Evidence Report/Technology Assessment 

Number 134 

B Vitamins and Berries and Age-Related 

Neurodegenerative Disorders 

Prepared for: 

Agency for Healthcare Research and Quality 

U.S. Department of Health and Human Services 

540 Gaither Road 

Rockville, MD 20850 

www.ahrq.gov 

Contract No. 290-02-0022 

Prepared by: 

Tufts-New England Medical Center Evidence-based Practice Center 

Boston, Massachusetts 

Investigators 

Ethan Balk, M.D., M.P.H., Principal Investigator 

Mei Chung, M.P.H., Research Associate 

Gowri Raman, M.D., Research Associate 

Athina Tatsioni, M.D., Research Associate 

Priscilla Chew, M.P.H., Research Associate 

Stanley Ip, M.D., Investigator 

Deirdre DeVine, M.Litt., Project Manager 

Joseph Lau, M.D., Project Director 

AHRQ Publication No. 06-E008 

April 2006
This report is based on research conducted by the Tufts-New England Medical Center 

Evidence-based Practice Center (EPC) under contract to the Agency for Healthcare Research 

and Quality (AHRQ), Rockville, MD (Contract No. 290-02-0022). The findings and 

conclusions in this document are those of the author(s), who are responsible for its content, 

and do not necessarily represent the views of AHRQ. No statement in this report should be 

construed as an official position of AHRQ or of the U.S. Department of Health and Human 

Services. 

The information in this report is intended to help clinicians, employers, policymakers, and 

others make informed decisions about the provision of health care services. This report is

intended as a reference and not as a substitute for clinical judgment. 

This report may be used, in whole or in part, as the basis for the development of clinical 

practice guidelines and other quality enhancement tools, or as a basis for reimbursement and 

coverage policies. AHRQ or U.S. Department of Health and Human Services endorsement of 

such derivative products may not be stated or implied. 
ii 

This document is in the public domain and may be used and reprinted without permission except 

those copyrighted materials noted for which further reproduction is prohibited without the 

specific permission of copyright holders. 

Suggested Citation: 

Balk E, Chung M, Raman G, Tatsioni A, Chew P, Ip S, DeVine D, Lau J. B Vitamins and 

Berries and Age-Related Neurodegenerative Disorders. Evidence Report/Technology 

Assessment No. 134. (Prepared by Tufts-New England Medical Center Evidence-based Practice 

Center under Contract No. 290-02-0022). AHRQ Publication No. 06-E008. Rockville, MD: 

Agency for Healthcare Research and Quality. April 2006. 

None of the investigators has any affiliations or financial 

involvement that conflicts with the material presented in 

this report. 
iii 

Preface 

The Agency for Healthcare Research and Quality (AHRQ), through its Evidence-Based 

Practice Centers (EPCs), sponsors the development of evidence reports and technology 

assessments to assist public-and private-sector organizations in their efforts to improve the 

quality of health care in the United States. This report on B Vitamins and Berries and AgeRelated Neurodegenerative Disorders was requested and funded by the National Center for 

Complementary and Alternative Medicine (NCCAM) and the Office of Dietary Supplements 

(ODS), National Institutes of Health. The reports and assessments provide organizations with 

comprehensive, science-based information on common, relevant scientific literature on topics 

assigned to them by AHRQ and conduct additional analyses when appropriate prior to 

developing their reports and assessments. 

 To bring the broadest range of experts into the development of the evidence reports and 

health technology assessments, AHRQ encourages the EPCs to form partnerships and enter into 

collaborations with other medical and research organizations. The EPCs work with these partner 

organizations to ensure that the evidence reports and technology assessments they produce will 

become building blocks for health care quality and improvement projects throughout the nation. 

The reports undergo peer review prior to their release. 

 AHRQ expects that the EPC evidence reports and technology assessments will inform 

individual health plans, providers, and purchasers as well as the health care system as a whole by 

providing important information to help improve health care quality. 

 We welcome comments on this evidence report. They may be sent to the Task Order Officer 

below at: Agency for Healthcare Research and Quality, 540 Gaither Road, Rockville, MD 

20850, or by e-mail to epc@ahrq.gov.

Carolyn M. Clancy, M.D. 

Director 

Agency for Healthcare Research and Quality 

Jean Slutsky, P.A., M.S.P.H. 

Director, Center for Outcomes and Evidence 

Agency for Healthcare Research and Quality 

Stephen E Straus, M.D. 

Director 

National Center for Complementary and 

Alternative Medicine 

National Institutes of Health 

Beth A. Collins Sharp, Ph.D., R.N. 

Acting Director, EPC Program 

Agency for Healthcare Research and Quality 

Paul M. Coates, Ph.D. 

Director 

Office of Dietary Supplements 

National Institutes of Health 

Margaret Coopey, M.P.S., M.G.A., R.N. 

EPC Program Task Order Officer 

Agency for Healthcare Research and Quality 
iv 

Acknowledgments 

We would like to acknowledge with appreciation the following members of the Technical Expert 

Panel for their advice and consultation to the Evidence-based Practice Center during preparation 

of this report. 

 

James Joseph, Ph.D.

Associate Professor 

Gerald J. and Dorothy R. Friedman School of 

Nutrition Science and Policy at Tufts University 

USDA Scientist 

Neuroscience Laboratory 

Jean Mayer USDA Human Nutrition Research 

Center on Aging at Tufts University 

Boston, Massachusetts 

Irwin H. Rosenberg, M.D. 

Senior Scientist and Director 

Nutrition and Neurocognition Laboratory 

Jean Mayer USDA Human Nutrition Research 

Center on Aging at Tufts University 

Boston, Massachusetts 

Alice H. Lichtenstein, D.Sc. 

Stanley N. Gershoff Professor of Nutrition Science 

and Policy 

Gerald J. and Dorothy R. Friedman School of 

Nutrition Science and Policy at Tufts University 

Senior Scientist, Director of the Cardiovascular 

Nutrition Laboratory 

Jean Mayer USDA Human Nutrition Research 

Center on Aging at Tufts University 

Boston, Massachusetts 

Thomas B. Shea, Ph.D. 

Center for Cellular Neurobiology and 

Neurodegeneration Research 

Department of Biological Sciences 

University of Massachusetts 

Lowell, Massachusetts 

Richard Nahin, Ph.D., M.P.H. 

Senior Advisor for Scientific Coordination 

National Center for Complementary and 

Alternative Medicine 

National Institutes of Health 

Bethesda, Maryland 

Anne Thurn, Ph.D. 

Director 

Evidence-Based Review Program 

Office of Dietary Supplements 

National Institutes of Health 

Bethesda, Maryland 

Henry W. Querfurth, M.D., Ph.D.

Associate Professor of Neurology and 

Neuroscience 

Tufts University School of Medicine 

Chief, Neurology Research 

Caritas St. Elizabeth’s Medical Center 

Boston, Massachusetts 

Nicholi Vorsa, Ph.D. 

Research Professor 

Plant Science 

Marucci Blueberry-Cranberry Research Center 

Plant Science/Chatsworth 

Chatsworth, New Jersey 

We would also like to acknowledge with appreciation the following person for her role as a Technical 

Expert Consultant to the EPC: 

Barbara Shukitt-Hale, Ph.D.

USDA Scientist, Neuroscience Laboratory, Jean Mayer USDA Human Nutrition Research 

Center on Aging at Tufts University, Boston, Massachusetts 
v 

Structured Abstract 

Objectives. To assess the effects, associations, mechanisms of action, and safety of B vitamins 

and, separately, berries and their constituents on age-related neurocognitive disorders – primarily 

Alzheimer’s (AD) and Parkinson’s disease (PD). 

Data Sources. MEDLINE® and CAB AbstractsTM. Additional studies were identified from 

reference lists and technical experts. 

Review Methods. Vitamins B1, B2, B6, B12, and folate, and a dozen types of berries and 

their constituents were evaluated. Human, animal, and in vitro studies were evaluated. Outcomes 

of interest from human studies were neurocognitive function or diagnosis with AD, cognitive 

decline, PD, or related conditions. Intervention studies, associations between dietary intake and 

outcomes, and associations between B vitamin levels and outcomes were evaluated. Specific 

mechanisms of action were evaluated in animal and in vitro studies. Studies were extracted for 

study design, demographics, intervention or predictor, and neurocognitive outcomes. Studies 

were graded for quality and applicability. 

Results. In animal studies, deficiencies in vitamins B1 or folate generally cause neurological 

dysfunction; supplementation with B6, B12, or folate may improve neurocognitive function. In 

animal experiments folate and B12 protect against genetic deficiencies used to model AD; 

thiamine and folate also affect neurovascular function and health. 

 Human studies were generally of poor quality. Weak evidence suggests possible benefits of 

B1 supplementation and injected B12 in AD. The effects of B6 and folate are unclear. Overall, 

dietary intake studies do not support an association between B vitamin intake and AD. Studies 

evaluating B vitamin status were mostly inadequate due to poor study design. Overall, studies do 

not support an association between B vitamin status and age-related neurocognitive disorders. 

 Only one study evaluated human berry consumption, finding no association with PD. Animal 

studies of berries have almost all been conducted by the same research group. Several berry 

constituents have been shown to affect brain and nerve tissue function. Blueberry and strawberry 

extract were protective of markers of disease, although effects on neurocognitive tests were less 

consistent. Berry extracts may protect against the deleterious effects of compounds associated 

with AD. 

Reporting of adverse events was uncommon. When reported, actual adverse events from B 

vitamins were rare and minor. 

Conclusions. The current research on B vitamins is largely inadequate to confidently assess 

their mechanisms of action on age-related neurocognitive disorders, their associations with 

disease, or their effectiveness as supplements. B vitamin supplementation may be of value for 

neurocognitive function, but the evidence is inconclusive. 

vii 

Contents 

Executive Summary.......................................................................................................................1 

Evidence Report...........................................................................................................................9 

Chapter 1. Introduction ...............................................................................................................11 

 Overview of Age-Related Neurodegenerative Disorders ......................................................11 

Proposed Mechanisms of the Effect of B Vitamins on Age-Related Neurodegenerative 

Disorders..........................................................................................................................13 

 Proposed Mechanisms of the Effect of Constituents in Berries on Age-Related 

 Neurodegenerative Disorders...........................................................................................15 

Chapter 2. Methods.....................................................................................................................17 

 Overview................................................................................................................................17 

 Key Questions Addressed in This Report..............................................................................17 

 B Vitamins .......................................................................................................................17 

 Berries..............................................................................................................................18 

 Approach To Analyzing the Literature..................................................................................18 

 Topic Refinement.............................................................................................................19 

 Eligibility Criteria ............................................................................................................19 

 Literature Search Strategy......................................................................................................22 

 Study Selection and Data Extraction .....................................................................................23 

 Data Extraction ................................................................................................................23 

 Grading of the Evidence ........................................................................................................24 

 Methodological Quality Grade (Human Studies) ............................................................24 

 Methodological Quality Grade (Animal / In Vitro Studies) ............................................25 

 Applicability Grade..........................................................................................................26 

 Reporting Results...................................................................................................................27 

 Outcomes Reported..........................................................................................................27

 Metrics Included ..............................................................................................................27 

 Evidence and Summary Tables........................................................................................28 

 Adverse Events Reporting ...............................................................................................29 

Chapter 3. Results .......................................................................................................................31 

 B Vitamins .............................................................................................................................31 

 Animal and In Vitro Studies: Mechanisms of Action.....................................................31 

Effects of B Vitamins on Cognitive Function, Movement Disorders, and Brain 

Neurotransmitters or Histopathology...................................................................32 

Effects of B Vitamins on the Expression or Function of Alzheimer’s 

Disease-Related Genes.........................................................................................40 

Effects of B Vitamins on Blood Brain Barrier or Cerebrovascular Endothelial 

Function ...............................................................................................................41 

 Human Studies.................................................................................................................44 

 Effect of B Vitamin Supplementation on Neurocognitive Function .........................46 

 Thiamine (Vitamin B1) Intervention Studies ......................................................46 
viii 

 Riboflavin (Vitamin B2) Intervention Studies.....................................................49 

 Vitamin B6 Intervention Studies .........................................................................49 

 Cobalamin (Vitmain B12) Intervention Studies ..................................................50 

 Folate Intervention Studies ..................................................................................56 

 Combined B Vitamins Intervention Studies ........................................................60 

 Association of Dietary Intake Levels of B Vitamins to Age-Related 

Neurodegenerative Diseases ................................................................................65 

 Longitudinal Studies ............................................................................................65 

 Cross-Sectional Studies .......................................................................................73 

 Association of Tissue Levels of B Vitamins to Age-Related Neurodegenerative 

Diseases................................................................................................................80 

 Thiamine (Vitamin B1) Level Association Studies.............................................80 

 Riboflavin (Vitamin B2) Level Association Studies ...........................................84 

 Vitamin B6 Level Association Studies................................................................84 

 Cobalamin (Vitamin B12) Level Association Studies.........................................89 

 Folate Level Association Studies.........................................................................99 

 B Vitamin-Homocysteine Interaction With Cognitive Function.......................108 

 B Vitamin Adverse Events.............................................................................................109 

 General Vitamin B Safety........................................................................................110 

Berries..................................................................................................................................112 

 Constituents in Berries...................................................................................................113 

 Antioxidants in Berries ............................................................................................114 

 Animal and In Vitro Studies: Mechanisms of Action...................................................115 

 Effects of the Constituents in Berries ......................................................................115 

 Effects of Berry Extract Supplementation ...............................................................119 

 Human Studies...............................................................................................................128 

 Berry Adverse Events ..............................................................................................128 

 

Chapter 4. Discussion ...............................................................................................................131 

Overview..............................................................................................................................131 

Main Findings ......................................................................................................................131 

 B Vitamins .....................................................................................................................131 

 Mechanisms of Action .............................................................................................131 

 B Vitamin Intervention Trials..................................................................................132 

 B Vitamin Dietary Intake Studies............................................................................134 

 B Vitamin Status Studies .........................................................................................134 

 Adverse Events ........................................................................................................136 

 Berries............................................................................................................................136 

 Constituents of Berries.............................................................................................136 

 Mechanisms of Action .............................................................................................136 

 Human Studies.........................................................................................................137 

 Adverse Effects........................................................................................................137 

Limitations ...........................................................................................................................137 

 Animal and In Vitro Studies ..........................................................................................137 

 Human Studies...............................................................................................................138 
ix 

Future Research ...................................................................................................................139 

 Human Studies...............................................................................................................139 

 Animal and In Vitro Studies ..........................................................................................140 

References and Included Studies ...............................................................................................143 

List of Acronyms/Abbreviations................................................................................................159 

 

Figures 

Figure 1. Summary findings of the effects of thiamine deficiency on rats’ cognitive 

function, movement disorders and brain histopathology.......................................................35 

Figure 2. Polyphenol family structure ......................................................................................115

Figure 3. Summary of the effects of blueberry extract supplementation on animal’s 

performance in neurocognitive testing or brain biochemistry or histology in 

adult or aged rat models.......................................................................................................122 

Figure 4. Summary of the effects of strawberry extract supplementation on animal’s 

performance in neurocognitive testing or brain biochemistry or histology in 

adult or aged rat models.......................................................................................................123 

Tables 

Table 1. Institute of Medicine Dietary Reference Intakes of B vitamins, functions, 

and sources.............................................................................................................................14 

Table 2. Thiamine deficient (intervention) vs. normal thiamine (control) diets.........................36 

Table 3. Vitamin B6 supplementation (intervention) vs. normal B6 (control) diets 

in healthy animals ..................................................................................................................37 

Table 4. Vitamin B12 supplements (intervention) vs. normal B12 (control) diets 

in diseased animals ................................................................................................................38 

Table 5. Folate deficiency (intervention) vs. normal folate (control) diets ................................39 

Table 6. Effects of B vitamins on blood brain barrier or cerebrovascular endothelial 

function ..................................................................................................................................43 

Table 7. Summary of intervention studies evaluating the effect of B vitamins on 

neurocognitive outcomes .......................................................................................................44 

Table 8. Summary of association studies evaluating the association of B vitamin intake 

or levels on neurocognitive outcomes....................................................................................45 

Table 9. Effect of thiamine (vitamin B1) intervention on cognitive function tests ....................48 

Table 10. Effect of vitamin B6 intervention on cognitive function tests....................................50 

Table 11. Effect of vitamin B12 intervention on cognitive function tests in randomized 

controlled trials ......................................................................................................................53 

Table 12. Effect of vitamin B12 intervention on cognitive function tests in 

non-randomized trials ............................................................................................................54 

Table 13. Effect of folic acid or folate intervention on cognitive function tests ........................58 

Table 14. Effect of combination B vitamin interventions on cognitive function .......................62 

Table 15. Association between dietary intake levels of vitamin B6 and neurodegenerative 

diseases or cognitive function in longitudinal studies ...........................................................68 
x 

Table 16. Association between dietary intake levels of vitamin B12 and neurodegenerative 

diseases or cognitive function in longitudinal studies ...........................................................70 

Table 17. Association between dietary intake levels of folate and neurodegenerative 

diseases or cognitive function in longitudinal studies ...........................................................71 

Table 18. Association between dietary intake of vitamin B1 (thiamine) and cognitive 

function in cross-sectional studies .........................................................................................75 

Table 19. Association between dietary intake of vitamin B2 (riboflavin) and cognitive 

function in cross-sectional studies .........................................................................................76 

Table 20. Association between dietary intake of vitamin B6 (pyridoxine) and cognitive 

function in cross-sectional studies .........................................................................................77 

Table 21. Association between dietary intake of vitamin B12 and cognitive function 

in cross-sectional studies........................................................................................................78 

Table 22. Association between dietary intake of folate and cognitive function in 

cross-sectional studies............................................................................................................79 

Table 23. Association of thiamine (vitamin B1) levels and prevalence of thiamine 

deficiency with cognitive function.........................................................................................81 

Table 24. Association of levels of thiamine or thiamine derivatives (vitamin B1) with 

diagnoses of age related neurocognitive disorders ................................................................82 

Table 25. Association of riboflavin (vitamin B2) levels with diagnosis of neurocognitive 

disorders.................................................................................................................................84 

Table 26. Association of serum PLP level with diagnosis of AD, dementia, cognitive 

decline and cognitive function status in longitudinal studies ................................................87 

Table 27. Association of serum PLP level with diagnosis of AD, cognitive impairment, 

dementia, and PD in retrospective cohorts, case-control, and cross-sectional studies ..........88 

Table 28. Association of serum vitamin B12 levels with diagnosis of AD, dementia, 

or cognitive decline in longitudinal studies ...........................................................................92 

Table 29. Association of serum vitamin B12 levels with cognitive function in 

cross-sectional studies............................................................................................................94 

Table 30. Studies reporting odds ratio (OR) or risk ratio (RR) for diagnosis of AD 

or cognitive impairment at threshold vitamin B12 serum levels ...........................................95 

Table 31. Studies reporting prevalence of subjects with threshold serum vitamin B12 

levels among those with dementia diagnoses ........................................................................96 

Table 32. Association of serum and CSF vitamin B12 levels with diagnoses of dementias 

in cross-sectional studies........................................................................................................97 

Table 33. Association of mean folate levels with diagnosis of age-related 

neurodegenerative disease ...................................................................................................101

Table 34. Prevalence of folate deficiency among subjects with dementia, cognitive 

impairment, and normal cognition.......................................................................................103 

Table 35. Folate level as a predictor of cognitive function in longitudinal studies..................105 

Table 36. Folate level as a predictor of cognitive function in case-control studies and 

cross sectional studies................................................................................................................107 

Table 37. Reported adverse events in B vitamin intervention studies......................................110 

Table 38. Institute of Medicine Dietary Reference Intakes of B vitamins and adverse 

 effects...................................................................................................................................112 

Table 39. USDA nutritional facts on selected raw berries (1 cup) ...........................................114 
xi 

Table 40. Effects of constituents in berries on animal’s performance in neurocognitive 

 testing or on their brain biochemistry ..................................................................................118 

Table 41. Effects of berry extracts on animal performance on neurocognitive testing 

 or brain biochemistry or histology.......................................................................................124 

Appendixes 

Appendix A: Literature Searches 

Appendix B: Sample Data Extraction Forms 

Appendix C: Evidence Tables 

Appendix D: Excluded Studies 

Appendix E: Peer Reviewers 

The Appendixes and Evidence Tables cited in this report are provided electronically at

http://www.ahrq.gov/downloads/pub/evidence/pdf/berry/berry.pdf

1 

Executive Summary 

Introduction 

 Disorders of the nervous system account for more long-term care, chronic suffering, and 

diminished quality of life than all other disorders combined. Age-related neurodegenerative 

disorders are chronic and progressive conditions that result from loss of the maintenance of 

neurons involved in cognitive, emotional, motor and sensory functions. The two most common 

age-related neurodegenerative disorders are Alzheimer’s (AD) and Parkinson’s diseases (PD). 

This report investigates the possible relationships both of B vitamin status and supplementation 

and of berry consumption with age-related neurodegenerative disorders. 

 This report was sponsored by the National Center for Complementary and Alternative 

Medicine (NCCAM) and the Office of Dietary Supplements (ODS), National Institutes of 

Health. 

Methods 

Key Questions 

B Vitamins 

1. What is the evidence regarding mechanisms of action of the B vitamins B1, B2, B6, B12, 

and folate (singly and in combination) for preventing, decreasing the rate of progression 

of, or reversing the neurological changes associated with age-related neurodegenerative 

conditions such as Parkinson’s or Alzheimer’s disease? 

2. What is the evidence that the B vitamins B1, B2, B6, B12, and folate can prevent, 

decrease the rate of progression of, or reverse the neurological changes associated with 

age-related neurodegenerative conditions such as Parkinson’s or Alzheimer’s disease in 

humans 

3. What adverse events in humans have been reported in the literature for supplementation 

with the B vitamins B1, B2, B6, B12, and folate? 

a. Do the frequency of adverse events vary with source, dose, or other 

 evaluated factors? 

Berries 

1. What are the constituents in berries with beneficial nerve- and brain-related health effects 

(from in vitro, animal, and human studies)? 

a. In what other food sources are these constituents found? 

2. What is the evidence regarding mechanisms of action of berry constituents for 

preventing, decreasing the rate of progression of, or reversing the neurological changes 

associated with age-related neurodegenerative conditions, including Parkinson’s or 

Alzheimer’s disease? 
2 

3. What is the evidence that the constituents of berries can prevent, decrease the rate of 

progression of, or reverse the neurological changes associated with age-related 

neurodegenerative conditions, including Parkinson’s or Alzheimer’s disease in humans 

a. Is the source, species, dose, composition, characteristics, or processing of berries 

and berry constituents related to the effect of the intervention? 

4. What adverse events in humans have been reported in the literature for the constituents in 

berries? 

a. Do the frequency of adverse events vary with source, dose, or other evaluated 

factors? 

 We reviewed all studies of berries and their constituents that addressed these questions, 

regardless of specific topic. However, for B vitamins we restricted the specific topics to the 

following: 

B Vitamins: Human Studies 

• Association between B vitamin treatment/intake with diagnosis or severity of AD or PD, 

cognitive function, or histopathology 

• Association of B vitamin status and AD or PD diagnosis, histopathology, severity of 

disease, or cognitive function 

B Vitamins: Animal / In Vitro Studies 

• Effect of B vitamin supplementation or deficiency on cognitive function, movement 

disorders, histopathology, etc., in appropriate models 

• Effect of B vitamins on the expression or function of AD-related genes 

• Blood brain barrier and cerebrovascular endothelial function in relation to B vitamins 

Approach To Analyzing the Literature 

General Inclusion Criteria 

Human studies. The common inclusion criteria for human studies consist of primary studies; 

English language publication, human adult subjects; analysis of the predictor or description, 

including quantification, of the intervention, and analysis of the following categories of 

outcomes: diagnosis or severity of AD, PD, other age-related neurocognitive disorders, or 

cognitive impairment; tests of cognitive function. We excluded other neuropsychiatric conditions 

and neuromotor diseases. For B vitamin interventions, we included only prospective trials. 

Animal / in vitro studies. Animal and in vitro studies had to be published in full form in English 

language journals. We included all animal and in vitro models of diseases of interest and all 

outcome measurements related to the outcomes and/or associations of interest. We excluded 

studies that used inappropriate animal or in vitro models. 

Literature Search Strategy. We conducted a comprehensive literature search to address the 

key questions. Final literature searches for English language publications on B vitamins and 

berries were conducted in MEDLINE® and the Commonwealth Agricultural Bureau (CAB) 
3 

AbstractsTM between February and March 2005. The searches included both human, animal, and 

in vitro studies. 

 Both the B vitamin and berry searches used a common neurocognitive model that included 

the following terms: nervous system diseases, cognitive disorders, neurodegeneration, dementia, 

Alzheimer, Parkinson, Lewy body, neuron/nerve cells, brain, and related terms. 

 Additional studies were sought by contacting members of the TEP, and from reference lists 

of selected included articles, review articles and meta-analyses. 

Data Extraction. The same data extraction forms were used for both the B vitamin and berry 

articles. Standard data extraction forms were used for human studies. For animal and in vitro 

studies, data extraction focused more on study hypotheses and conclusions than on design and 

quantitative results. 

Grading of the Evidence 

 We used a 3-category grading system (A, B, C) to denote the methodological quality of each 

study. This system, with variations in criteria, was used for both human and animal studies. 

Separate criteria were used for human intervention studies, human association studies, and 

animal studies to account for different issues related to these types of studies. 

A Category A studies have the least bias and results are considered valid. 

B Category B studies are susceptible to some bias, but not sufficient to invalidate the 

results. 

C Category C studies have significant bias that may invalidate the results. 

Human studies were also assessed for applicability: 

ddd Sample is representative of the target population. 

dd Sample is representative of a relevant sub-group of the target population. 

d Sample is representative of a narrow subgroup of subjects only. 

Results 

B Vitamins 

 For B vitamins, 85 human studies and 17 animal or in vitro studies were evaluated. Although 

the review covers both neurocognitive function related to AD and related diseases and the 

movement disorders and motor systems degeneration related to PD and related diseases, only 

scant evidence was found regarding PD-related conditions. 

Mechanisms of Action. Overall, research has shown that there were negative effects of 

thiamine, vitamin B6 and folate deficiency on animal’s clinical status and/or histopathology, 

although not all deficient animals had worse performance in neurocognitive tests. Studies have 

found some positive effects of the supplementations of vitamin B6, vitamin B12, and folate on 

animal’s performance in neurocognitive tests. Folate deficiency also showed a synergistic effect 

with both PD and AD pathology. Folate appears to protect against oxidative damage associated 

with ApoE gene knockout mouse models. Folate and B12 deficiency also induce presenilin-1, 

but do not appear to affect amyloid precursor protein. Thiamine (vitamin B1) is required for 
4 

active transport of pyruvate across the blood brain barrier and maintaining integrity and normal 

permeability of the blood brain barrier. Folate is protective against homocysteine-induced 

cerebrovascular damage. 

B Vitamin Intervention Trials 

Vitamin B1. Three randomized controlled trials (RCTs), one non-randomized comparative trial 

and one uncontrolled cohort study that assessed the effect of thiamine intervention among people 

with either probable or possible AD were heterogeneous in their outcomes. Most found 

improvements in cognitive function or a slowed rate of deterioration using some measures of 

cognitive testing, either compared to control or in uncontrolled studies. However, either no 

difference between treatment and control or no improvement with thiamine supplementation was 

found in all studies with other measures of cognitive function. Only the uncontrolled cohort 

study reported blood levels of thiamine before intervention and included AD subjects with 

normal levels. 

Vitamin B2. No prospective trial has evaluated the effect of B2 treatment on neurocognitive 

function. 

Vitamin B6. Only two RCTs of cognitively intact population investigated the effect of B6 

intervention on cognitive function. Participants had B6 levels within normal range in both trials. 

With treatment, a significant improvement was found in one of the RCTs with one cognitive 

function test. No other significant change was reported in the studies. 

Vitamin B12. Five RCTs, one non-randomized comparative trial, and seven cohort studies 

assessed the effect of B12 intervention on cognitive function. Seven of these studies recruited 

participants with low B12 levels, while the remaining five studies assessed individuals with 

normal B12 levels. There was a large degree of heterogeneity across the studies. Although 

several studies suggested some improvement in cognitive function, few reached statistical 

significance. Results were frequently conflicting. Vitamin B12 was given intramuscularly in the 

only RCT that found a significant effect in the treatment group compared with the controls. 

Similarly, only cohort studies that used intravenous or intramuscular vitamin B12 reported a 

significant effect on cognitive function scores. However, the lack of data directly comparing oral 

and injected routes of vitamin B12 and the paucity of controlled trials limits any conclusions 

regarding the utility of different routes of administration. 

Folate. Three RCTs and two uncontrolled cohort studies reported data on the effect of folate 

intervention. One RCT of subjects with dementia and normal folate levels found worse 

neuropsychological scores in the folate treatment group among subjects with dementia. Two 

other studies, one RCT and one cohort study, found significant improvement with folate 

supplementation compared to placebo in different populations. The study of patients with PD 

found no therapeutic benefit. Three studies reported blood folate levels before intervention, of 

which only two studies (one RCT and one cohort study) included patients with low folate levels. 

Combination of B vitamins. Three RCTs and three uncontrolled cohort studies assessed the 

effects of a combination of B vitamins as interventions on cognitive function. Each used 

different daily doses of various B vitamins including folate, B6, and B12. All but one found no 

significant change in cognitive function after combination B vitamin supplementation. Only one 
5 

RCT assessed the effects of combined vitamin intervention on patients with low blood folate 

levels; the remainder of the studies included patients with normal mean blood vitamin levels. 

B Vitamin Dietary Intake Studies. Five longitudinal studies and five cross-sectional studies 

examined the association between the dietary intake levels of B vitamins and cognitive function 

or the risk of age-related neurodegenerative diseases. No significant associations were found 

between dietary intakes of B6 or B12 and PD, AD, cognitive function, or cognitive decline 

across three studies. One additional study found dietary intakes of B6 and B12 were positively 

associated with improvements in some, but not all, cognitive function measures. Two studies 

found opposite relationships between dietary intakes of folate and cognitive function in aging 

populations. Among the five cross-sectional studies, one found that subjects with low intake of 

thiamine, vitamins B2, B6, and folate, but not B12, scored significantly worse on verbal memory 

than those with relatively high intake levels. A second study found an association between 

vitamin B2 intake and cognitive testing in women, but not men. No association between dietary 

intake of B12 and cognitive function or diagnosis of AD was found in all five cross-sectional 

studies. 

B Vitamin Status Studies 

Overall. The association between thiamine status and age-related cognitive disorders is unclear. 

Half the studies found no associations and half found lower levels of thiamine or thiamine 

derivatives in tissues of patients with AD, cognitively impairment, and PD. However, none of 

these studies could differentiate between cause and effect (e.g., low thiamine levels resulting in 

disease vs. changes due to disease, including nutritional intake, resulting in low thiamine levels). 

The studies also failed to adjust for potential confounders. The cross-sectional studies of vitamin 

B2 found no association with diagnosis of AD, but low levels among people with PD (mean 101 

ng/mL, where the normal range is 125 to 300 ng/mL). The large majority of vitamin B6 studies 

found no association between B6 status and the diagnosis of dementia or cognitive impairment, 

or cognitive function. A large number of studies have evaluated both vitamin B12 and folate 

status. Most of the longitudinal studies of vitamin B12 failed to find an association with 

diagnosis or severity of disease. While trends toward lower B12 levels among people with AD 

were found in cross-sectional studies, these associations were not consistent and proper 

adjustment for potential confounders was rarely performed. Both the longitudinal and casecontrol studies of folate status mostly reported an association between low folate levels (defined 

differently in different studies) and future diagnosis of AD and/or cognitive impairment. No 

association with PD was found. 

Berries 

 One human study and 18 animal or in vitro studies (with 19 experiments) were evaluated. 

Constituents of Berries. Only a limited number of the numerous constituents in berries have 

been examined separately from the rest of the fruit. These include tannins (procyanidin and 

prodelphinidin), anthocyanins and phenolics, from various berries. 

Mechanisms of Action 

Effects of the constituents in berries. One study showed that bilberry extract containing 

anthocyanins significantly increased rat brain uptake of triiodothyronine (T3). One study 
6 

reported that 18 plant tannins, including those found in blueberry, red currant, and gooseberry, 

generally inhibit brain protein kinase C to a similar degree; however, the biological significance 

in live animals of this in vitro inhibition is unknown. One study demonstrated that that the 

anthocyanins in blueberry extracts were able to cross the blood brain barrier and the number of 

the total anthocyanins measured in the brain is associated with rats’ learning performance. One 

study compared the effects of specific berry constituents on neurocognitive outcomes in rats. It 

did not appear that the anthocyanin component was solely responsible for improvements seen. 

Effects of berry extract supplementation. Berry extracts were used to supplement animals’ diet 

or added to in vitro study media in 14 studies with 15 experiments. Of these, only two studies 

used specific animal or in vitro models of AD. All of these studies were from the same group of 

investigators. 

 Blueberry and strawberry extract supplementation showed improved or protective effects on 

almost all biochemical markers and histology findings examined in the normal-aging rat brain, 

although only some of the neurocognitive tests and psychomotor functions were significantly 

improved. 

 Two studies used models of AD. The results suggested that it may be possible to reduce both 

the deleterious effects of dopamine and the putative toxic effects of amyloid β via various berry 

extracts. In mouse models with amyloid precursor protein and presenilin-1 mutations, blueberry 

extract supplementation seemed to prevent the deficits in Y-maze performance seen in the 

transgenic animals fed the control diets, although it did not affect amyloid β deposits. 

Human Studies. Only one study evaluated any association between berry (or berry constituent) 

intake and neurocognitive function. A case-control study of patients with PD found that the 

preference to consume blueberries or strawberries was not statistically significantly associated 

with PD. 

Adverse Events 

 Only 10 B vitamin studies reported adverse events among 254 subjects receiving B vitamin 

supplementation. These mostly reported no adverse events. The two studies reporting complaints 

cited mild gastrointestinal complaints in patients with AD taking high dose thiamine and possible 

mild neurological complaints with folate in patients with PD. 

Limitations 

Animal and In Vitro Studies 

 Few studies used specific, well-established models for AD or PD. Most were performed in 

normally aging rodents. It has also not yet to be established that the neurocognitive tests used in 

the experiments correspond to deficits seen in AD or PD. Most studies used models of severely 

vitamin deficient rodents. While these studies might elucidate which B vitamins are required for 

maintenance of brain function, they rarely addressed the question of the actual mechanism of 

action of the B vitamins. Almost all the studies of berries have been performed in a single 

laboratory. The grading of quality for animal and in vitro studies remains even less well 
7 

validated than grading of human studies; however, improvements are clearly needed in the 

design and reporting of these studies. 

Human Studies 

 Only a single, retrospective, human study of berries and PD has been reported. Among the 

human B vitamin studies, the majority were of poor quality. The majority of data come from 

cross-sectional studies, most of which failed to adjust for potential confounders. Among the trials 

of B vitamin supplementation, a large number were not RCTs. 

 All the B vitamin studies as a group also suffered from lack of standardization of B vitamin 

measurement technique, of normal ranges for B vitamins, of definitions of diagnoses of various 

dementias, and of tests of cognitive function. On the order of 50 different tests or subtests were 

used across the studies. There is scant evidence regarding the effect of B vitamins on PD. 

Conclusions 

 The current research is largely inadequate to confidently assess the associations between B 

vitamin status and either disease or severity of disease, the effectiveness of B vitamin 

supplementation to prevent or ameliorate AD or PD, or putative mechanisms of action of B 

vitamins on age-related neurocognitive disorders. 

 In animal models, B vitamin deficiencies cause reproducible deficits and lesions and there is 

evidence to suggest a role for folate and vitamin B12 in regulating some genes and gene products 

related to AD. 

 There is limited evidence that injected vitamin B12 supplementation is of clinical benefit 

among demented or cognitively impaired patients, particularly when given soon after diagnosis 

of disease; however, overall the studies of B12 supplementation are inconclusive and the relative 

value of injected versus oral B12 remains unclear. Similarly, folate supplementation may also 

improve cognitive function but the clinical importance of the results remains unclear. Of note, 

though one study of folate supplementation found a significant worsening of cognitive function 

in treated patients with dementia. Other B vitamin treatments, including combination treatments, 

have not been shown to affect AD. Insufficient studies evaluated PD and no study evaluated 

vitamin B2 supplementation. The available literature does not conclusively support associations 

of B vitamin status as having an effect on age-related neurocognitive disorders. Conclusions are 

limited largely due to the poor quality of the research. 

 Almost all studies of berries and neurocognitive function have been performed by a single 

group of researchers. The large majority of studies have used blueberry and strawberry extract 

supplementation, both of which produced positive effects on biochemical markers and histology 

findings, and some neurocognitive tests and psychomotor functions. In studies of specific rodent 

models of AD, various berry extracts ameliorated the deleterious effects of the AD-related 

genetic defects. The human data are insufficient to make conclusions. 
8 

Future Research 

Animal and In Vitro Studies 

 To clarify the actual biological or physiological responses that B vitamins may have on 

processes specific to age-related neurocognitive function, particularly PD, further studies would 

be needed. Studies in this field should be performed in a manner that will allow reproducibility, 

cross-species validation, and clear association with human brain processes. Likewise, 

understanding of what are the specific constituents in berries that appear to be of benefit, would 

require further investigation. Several questions of interest will continue to be difficult to address 

from human studies given ethical and practical limitations. Topics of particular interest that may 

be more suitable to animal research include sorting out the independent effects of elevated 

homocysteine and of low B vitamin levels and/or intake, and clarifying the relative harm of B 

vitamin deficiency (or benefit of B vitamin supplementation) in different stages of health or 

neurocognitive disease. Several large observational studies in humans have attempted to address 

the interaction with homocysteine, however, without the ability to closely control homocysteine 

and B vitamin levels (or intake) it is unlikely that human studies will definitively answer this 

question. 

Human Studies 

 Due to either the limited amount of available data or the poor quality of the bulk of the 

research to date, well-performed, well-analyzed, large, prospective studies would be needed to 

address all the questions posed regarding the effects and associations between either B vitamins 

or berries and age-related neurocognitive function. Future studies should use only well-verified 

and commonly used measurement criteria for both predictors and outcomes. This may require 

additional research to verify the value of measurement tools for neurocognitive function. Further 

cross-sectional studies are of very limited value. Any human studies of both B vitamins and 

berries should be more of practical than theoretical value. For example, both dietary and 

supplementation studies should evaluate doses that a normal person can both easily incorporate 

into their lifestyle and afford, instead of testing regimens that could not be reasonably followed 

by most people. 
EVIDENCE REPORT

11

Chapter 1. Introduction 

 The report on B Vitamins and Berries and Age-Related Neurodegenerative Disorders 

consists of 2 separate, but related, systematic reviews. Although sharing the same outcomes of 

interest, research on the effects of B vitamins and on the effects of berries do not overlap. 

However, given the shared outcomes of interest and the small amount of literature on berries 

research, this report covers both topics. The report is structured such that each chapter includes 

separate sections for information regarding both topics, for the B vitamin topic, and for the 

berries topic. In particular, the Results chapter is divided into 2 sections, one each for the B 

vitamin topic and the berries topic. 

 We begin with a general overview of age-related neurodegenerative disorders, followed by 

information on B vitamins and their proposed mechanisms of actions on age-related 

neurodegenerative disorders, and subsequently a brief introduction to berries and their proposed 

mechanisms of action. A detailed discussion about berry constituents is reserved for the Results 

chapter in response to the first berry Key Question. 

Overview of Age-Related Neurodegenerative Disorders 

 Disorders of the nervous system account for more long-term care, chronic suffering, and lost 

quality of life than all other disorders combined.1 Age-related neurodegenerative disorders are 

chronic and progressive conditions that result from loss of the maintenance of neurons involved 

in cognitive, emotional, motor and sensory functions.2 Different neurological disorders are 

associated with different patterns of cell loss and different intra- or extracellular deficiencies 

(such as changes in the intracellular signal transduction pathways and intercellular signal 

molecules) or deposits in the brain. The two most common age-related neurodegenerative 

disorders are Alzheimer’s and Parkinson’s diseases. 

 Alzheimer’s disease (AD) affects over 4 million people in the United States.2 It is the cause 

of about two-thirds of all cases of dementia.3

 The prevalence of AD rises exponentially with age 

among the elderly such that up to half of 95 year olds are affected.4 AD is a progressive 

neurological disease that results in the irreversible loss of brain neurons. It results in progressive 

impairment in memory, judgment, decision making, orientation to physical surroundings and 

language. Definitive diagnosis can be made only at autopsy, where the pathological hallmarks 

are neuronal loss, amyloid β-peptide plaques, and neurofibrillary tangles (or tau proteins). 

Human, animal model, and in vitro studies of AD generally focus on cognitive and language 

function or changes related to the pathological hallmarks. 

 The major dementia syndromes include AD, vascular disease, Lewy body dementia, 

Parkinson’s disease with dementia, frontotemporal dementias, and reversible dementias. The 

most common form of dementia among elderly is AD followed by the vascular dementia. AD 

has one or more of the following clinical features: a decrease in the level of cognition, behavioral 

disturbance, and interference to activities of daily living and independence. The most frequent 

clinical symptom is impairment in short and long-term memory. AD is synonymously known as 

dementia of Alzheimer disease, presenile and senile dementia, senile dementia of Alzheimer 

type, etc. AD is also categorized as type 1, type 2, type 3, and type 4 based on the age of onset, 

familial inheritance, genetic mutation, severity of disease and the rate progression. 
12

 The National Institute of Neurological and Communicative Disorders and Stroke and the 

Alzheimer’s Disease and Related Disorders Association (NINCDS-ADRDA) includes criteria 

for diagnosis of AD that has an 80% positive predictive value.5 The Diagnostic and Statistical 

Manual of Mental Disorders - Fourth Edition (DSM-IV) also includes criteria for diagnosis of 

AD. The diagnosis of AD in a clinical setting involves careful history preferably from the 

caretaker or family of the patient, assessment of cognitive function, physical and neurological 

examination, and laboratory and imaging work-up of the patient. The most frequently used test to 

assess neurocognitive function is the Mini-Mental Examination (MMSE). Extensive evaluation 

of the multiple domains of the cognitive function can also be done using a battery of 

neuropsychological tests such as Dementia Rating Scale (DRS), the Wechsler Adult Intelligence 

Scale-Revised (WAIS-R), among others. 

 Parkinson’s disease (PD) affects over 1 million people in North America,6 making it the 

second most common neurodegenerative disease.3 The prevalence of PD also rises with age, but 

at a much lower rate than AD; approximately 0.5 to 1 percent of 65 to 69 year olds are affected, 

rising to 1 to 3 percent among those 80 years and older.7 PD is characterized by resting tremor, 

bradykinesia (a decrease in spontaneity and movement), rigidity, and postural instability. Brain 

pathology is seen due to the loss of neurons in the substantia nigra in association with 

proteinaceous deposits known as Lewy bodies. Human, animal model, and in vitro studies of PD 

generally focus on related motor and neurological function or changes related to the pathological 

hallmarks. 

 A large number of other conditions result from progressive loss of neurons or neuronal 

function in various parts of the brain or due to numerous factors.8 These include mild “benign” 

motor and cognitive changes common among aging individuals and hundreds of rarely studied 

specific syndromes with heterogeneous clinical and pathological expressions. 

 Based on a recent review article, pharmacotherapy of AD and other dementias can only 

provide modest cognitive or disease-modifying benefits.9

 However, even modest benefits may 

have significant effects on quality of life, caregiver burden, and societal economic costs. The 

principle recommended initial treatment for patients with AD is a cholinesterase inhibitor, 

regardless of severity illness. Other interventions are commonly tried, although none is 

recommended, primarily due to lack of evidence of a benefit. These include, among other 

treatments, hormone replacement therapy, anti-inflammatory treatments, gingko biloba, and 

various vitamin supplementations. 

 Basic science research has established the important role of genetics in both AD and PD. For 

AD, hypotheses have been proposed that mutations in precursor proteins and genes are 

associated with increased cellular production of products that are toxic to neurons. The first gene 

linked to familial AD is located on chromosome 21 and encodes the β-amyloid precursor protein 

(APP), the source of the 40 to 42 amino acid amyloid β-peptide that forms insoluble amyloid 

plaques in the brain of all AD patients. Two other genes linked to early-onset familial AD are 

those encoding presenilin-1 (PS1, on chromosome 14) and presenilin-2 (PS2, on chromosome 

1).10 For PD, the alpha-synuclein gene (SNCA) has been implicated in autosomal dominant 

forms of the disease.11 There is a dosage effect according to the number of supernumerary copies 

of this gene (the number of gene duplications exceeding normal) in familial PD.12 Other factors 

that have been implicated in neuronal degeneration are mitochondrial dysfunction, oxidative 

stress, deficient neurotrophic support, and immune mechanisms.6

 

 Although the mechanisms responsible for the neuronal degeneration seen during both normal 

aging and neurodegenerative disease states are not fully understood, the degeneration is thought 
13

to be caused by increased vulnerability to metabolic and extra-metabolic sources of free radicals 

in aging brains.13-17 An example of the possible role of oxidative stress in dementia is suggested 

by a recent study that found an increased plasma homocysteine level to be an independent risk 

factor for the development of dementia and AD in 1,092 participants (mean age, 77 years) from 

the Framingham cohort with a median follow-up of 8 years.18 With the variety of different 

possible pathogenic mechanisms in neuronal damage, development of therapies for these agerelated neurodegenerative diseases will depend on further advances in our basic understanding of 

the underlying disease mechanisms. Such knowledge can potentially help in identifying high-risk 

individuals and lead to the development of therapies capable of halting the progression of the 

disorders before irreversible damage occurs. 

Proposed Mechanisms of the Effect of B Vitamins on 

Age-Related Neurodegenerative Disorders 

 Here and throughout the report, we focus of the specific B vitamins B1 (thiamine), B2 

(riboflavin), B6 (primarily pyridoxine), B12 (cobalamin), and folate (folic acid, tetrahydrofolate, 

etc.). Thiamine and riboflavin exist in a variety of food sources, including enriched and wholegrain cereals, organ meats, milk, and various vegetables. A balanced diet is generally sufficient 

for adequate intake of these vitamins. Dietary vitamin B6 and B12 generally come from animal 

protein foods (including meat, poultry, seafood, and eggs) and enriched cereals, and the major 

food sources of folate include green vegetables, citrus fruits, various whole grains, and, recently 

folate-enriched flour. 

 Thiamine and riboflavin, along with niacin, function in various biochemical pathways in the 

metabolism of glucose, amino acids, and fatty acids.19 Thiamine deficiency, particularly 

associated with alcohol abuse, can result in Wernicke-Korsakoff syndrome, a distinct condition 

including dementia and psychosis resulting from lesions and thinning in multiple areas of the 

brain. There is increasing research in high-dose thiamine or riboflavin treatments in patients with 

AD and PD, even though the underlying mechanisms of action are unknown.20 A recent 

Cochrane systematic review of the efficacy of thiamine for people with AD was inconclusive due 

to the small number of randomized controlled trials and poor reporting of results in the included 

trials.21 The most common clinical manifestations reported in humans during vitamin B6 

deficiency have been central nervous system changes and abnormal electroencephalography 

(EEG). Studies have showed that only 2 to 4 weeks of B6-depletion diet could result in abnormal 

EEG tracing in healthy young adults.22,23

 The coenzymes of vitamin B12, folate, and vitamin B6 (methylcobalamine, methyl 

tetrahydrofolate and pyridoxal-5’-phosphate, respectively), along with choline, interact to control 

serum homocysteine levels.19 Increased levels of homocysteine, a metabolite of the amino acid 

methionine, as well as decreased folate and vitamin B12 levels have been associated with normal 

aging. Correlations between high serum concentrations of homocysteine (in conjunction with 

low folate, vitamin B6 and vitamin B12) and decreased performance on cognitive tests have been 

reported.24,25 

 Older adults are at risk of vitamin B12 deficiency because its absorption may decline with 

aging. Vitamin B12 is necessary for folate metabolism. Methionine synthase, a vitamin B12-

dependent enzyme, facilitates the conversion of 5-methyltetahydrofolate to tetrahydrofolate by 

converting homocysteine to methionine. Derivatives of tetrahydrofolate are important for 
14

nucleotide biosynthesis. When deficiency of vitamin B12, dietary folate would stay 

methyltetrahydrofolate form in the body. The “methyltetrahydrofolate trap” phenomenon breaks 

the cycle of folate metabolism Folate acts as a cofactor in many biochemical reactions by 

donating and accepting one-carbon units.11 It is essential in nucleic acid synthesis and 

methylation reactions in the central nervous system. Animal and cell culture models of 

neurodegenerative disorders have shown that low-folate/high-homocysteine diets or folate 

deficiency may render neurons vulnerable to dysfunction and death. Specifically, dietary folate 

deficiency and elevated homocysteine levels were showed to promote accumulation of DNA 

damage and sensitizes neurons to amyloid β-peptide toxicity in experimental models of AD, and 

to endanger dopaminergic neurons in experimental models of PD.26,27 Also important to the 

evaluation of folate supplementation to prevent or treat neurodegenerative disorders is that 

excess folate intake can mask a vitamin B12 deficiency.19

 Recommended Daily Allowances (RDA), Upper Limits (UL), and selected food sources of 

the B vitamins, as compiled by the Institute of Medicine (IOM) are presented in Table 1. 

 Overall, the B vitamins are known to function in several anti-oxidant, anti-inflammatory 

mechanisms, along with nucleotide biosynthesis and nerve function. However, a complete 

understanding of the underlying mechanisms and the relationship between B vitamins and 

neurodegenerative disorders, however, is still lacking. 

Table 1. Institute of Medicine Dietary Reference Intakes of B vitamins, functions, and sources 

Nutrient Function Life Stage 

Group RDA ULa

 Selected Food Sources 

Males (mg/d) 

≥31 yr 1.2 nd 

Females 

Thiamine Coenzyme in the 

metabolism of 

carbohydrates and 

branched chain 

amino acids 

≥31 yr 1.1 nd 

Enriched, fortified, or whole-grain 

products; bread and bread 

products, mixed foods whose 

main ingredient is grain, and 

ready-to eat cereals 

Males (mg/d) 

≥31 yr 1.3 nd 

Females 

Riboflavin Coenzyme in 

numerous 

oxidation/reduction 

reactions ≥31 yr 1.1 nd 

Organ meats, milk, bread 

products and fortified cereals 

Vitamin B6 Males (mg/d) 

31-50 yr 1.3 100 

≥50 yr 1.7 100 

Females 

31-50 yr 1.3 100 

Comprises a group of 3 

vitamers: pyridoxal, pyridoxine, 

pyridoxamine; and 

5’-phosphate coenzymes of 

each vitamer 

Coenzyme in the 

metabolism of 

amino acids, 

glycogen and 

sphingolipid bases

≥50 yr 1.5 100 

Fortified cereals, organ meats, 

fortified soy-based meat 

substitutes 

Males (μg/d) 

≥31 yr 2.4 nd 

Females 

Vitamin B12 

Including its coenzymes 

methylcobalamin and 

adenosylcobalamin 

Coenzyme in amino 

acid and organic 

acid metabolism; 

prevents 

megaloblastic 

anemia 

≥31 yr 2.4 nd 

Fortified cereals, meat, fish, 

poultry 

Folate Males (μg/d) 

≥31 yr 400 1000

Females 

Note: Given as dietary folate 

equivalents (DFE). 1 DFE = 1 

μg food folate = 0.6 μg of folic 

acid from fortified food or as a 

supplement consumed with 

food. 

Coenzyme in the 

metabolism of 

nucleic and amino 

acids; prevents 

megaloblastic 

anemia 

≥31 yr 400 1000

Enriched cereal grains, grain 

products, and bread products; 

dark leafy vegetables 

Derived from Institute of Medicine report accessed at www.iom.edu/Object.File/Master/7/296/0.pdf via 

www.nal.usda.gov/fnic/etext/000105.html (accessed July 27, 2005). 

RDA = Recommended Daily Allowance; UL = Upper Limit. 
15

a UL = The maximum level of daily nutrient intake that is likely to pose no risk of adverse effects. Unless otherwise 

specified, the UL represents total intake from food, water, and supplements. Due to lack of suitable data, ULs could 

not be established for thiamin, riboflavin, or vitamin B12. In the absence of ULs, extra caution may be warranted in 

consuming levels above recommended intakes.

Proposed Mechanisms of the Effect of Constituents in 

Berries on Age-Related Neurodegenerative Disorders

 There is convincing epidemiological evidence suggesting that eating fruits and vegetables 

may reduce the risk of cardiovascular disease and many cancers.28 It has been hypothesized that 

these potential health benefits are due in part to the presence of antioxidant compounds in these 

foods. These beneficial compounds, such as carotenoids, vitamin C, vitamin E, polyphenols, and 

selenium, have been grouped together as dietary antioxidants. However, despite this grouping, 

these compounds can differ considerably from each another. Other non-antioxidant nutrients in 

fruits and vegetables, such as fiber, potassium and folate, have also been associated with several 

beneficial health effects.28 The discussion of primary constituents in berries being considered 

regarding an effect on neurocognitive function is in the Results chapter, in response to the berries 

Key Question 1 regarding this topic. 

 Briefly, there is considerable research demonstrating the increased susceptibility of the aging 

brain to both oxidative stress and inflammation.29 Data from animal and in vitro studies suggests 

that among the many sources of antioxidants, phytochemicals (flavonoids, phenolic acids and 

terpenes, derived from plants) have a beneficial role with respect to brain aging and 

neurodegenerative disorders through the combination of their anti-oxidative, anti-inflammatory, 

anti-viral, anti-proliferative, and anti-carcinogenic properties.30 Since oxidative stress and 

inflammation appear to be involved in brain aging and in neurodegenerative disease states,29 it is 

theorized that increased consumption of antioxidants may be effective in preventing or 

ameliorating these changes.

17

Chapter 2. Methods 

Overview 

 This evidence report on B vitamins and berries and age-related neurodegenerative disorders 

is based on a systematic review of the literature. The Tufts-New England Medical Center 

Evidence-based Practice Center (Tufts-NEMC EPC) held meetings and teleconferences with a 

technical expert panel (TEP) to identify specific issues central to this report. The TEP was 

comprised of technical experts in basic and clinical research in neuroscience, nutrition, 

B vitamins, and berries. A comprehensive search of the medical literature was conducted to 

identify studies addressing the key questions. Evidence tables of study characteristics and results 

were compiled, and the methodological quality and the applicability of studies were appraised. 

Study results were summarized with both qualitative and quantitative reviews of the evidence, 

evidence and summary tables 

 A number of individuals and groups supported the Tufts-NEMC EPC in preparing this report. 

The TEP served as our science partner. It included technical experts, representatives from the 

Agency for Healthcare Research and Quality (AHRQ), and both the National Center for 

Complementary and Alternative Medicine (NCCAM) and the Office of Dietary Supplements 

(ODS) at the National Institutes of Health (NIH). The TEP worked with the EPC staff to refine 

key questions, identify important issues, and define parameters for the report. Additional clinical 

domain expertise was obtained through local experts who joined the EPC. A draft version of this 

report was critically appraised by a panel of peer reviewers.*

 Revisions were made based on their 

comments; although all statements within the report are those of the authors only. 

 The review process and the report have been structured to account for the separate, but 

parallel, issues related to the effects of B vitamins and of berries. Processes related to 

neuroscience and to understanding animal and in vitro studies occurred in conjunction with all 

team members and relevant TEP members, whereas those related to either B vitamins or berries 

specifically occurred separately. Because of the small amount of literature related to berries and 

neurocognitive outcomes, the report encompasses both interventions. The report Introduction, 

Results, and Discussion chapters are structured such that common issues and topics are discussed 

first, followed by B vitamins, and then berries. 

Key Questions Addressed in This Report 

B Vitamins 

1. What is the evidence regarding mechanisms of action of the B vitamins B1, B2, B6, B12, 

and folate (singly and in combination) for preventing, decreasing the rate of progression 

of, or reversing the neurological changes associated with age-related neurodegenerative 

conditions such as Parkinson’s or Alzheimer’s disease? 

 

* Appendixes cited in this report are provided electronically at 

http://www.ahrq.gov/downloads/pub/evidence/pdf/berry/berry.pdf.
18

2. What is the evidence that the B vitamins B1, B2, B6, B12, and folate can prevent, 

decrease the rate of progression of, or reverse the neurological changes associated with 

age-related neurodegenerative conditions such as Parkinson’s or Alzheimer’s disease in 

humans 

3. What adverse events in humans have been reported in the literature for supplementation 

with the B vitamins B1, B2, B6, B12, and folate? 

a. Do the frequency of adverse events vary with source, dose, or other 

 evaluated factors? 

Berries 

1. What are the constituents in berries with beneficial nerve- and brain-related health effects 

(from in vitro, animal, and human studies)? 

a. In what other food sources are these constituents found? 

2. What is the evidence regarding mechanisms of action of berry constituents for 

preventing, decreasing the rate of progression of, or reversing the neurological changes 

associated with age-related neurodegenerative conditions, including Parkinson’s or 

Alzheimer’s disease? 

3. What is the evidence that the constituents of berries can prevent, decrease the rate of 

progression of, or reverse the neurological changes associated with age-related 

neurodegenerative conditions, including Parkinson’s or Alzheimer’s disease in humans 

a. Is the source, species, dose, composition, characteristics, or processing of berries 

and berry constituents related to the effect of the intervention? 

4. What adverse events in humans have been reported in the literature for the constituents in 

berries? 

a. Do the frequency of adverse events vary with source, dose, or other evaluated 

factors? 

Approach To Analyzing the Literature 

 To guide the assessment and synthesis of the literature, we used an expanded version of the 

generally-referred-to “PICO” method (Population, Intervention, Comparator, Outcomes) to 

define the parameters of interest. We used this approach for analysis of both human, animal, and 

in vitro studies. With input from the TEP, we asked the following questions to establish the 

literature review criteria: 

• What are the populations of interest? 

• What are the interventions of interest? 

• What are the comparators of interest? 

• What are the (marker/intermediate and clinical) outcomes of interest? 

• What are the health conditions of interest? 

• What are acceptable study designs? 
19

Topic Refinement 

 In regards to both studies that examine putative mechanisms of action on neurodegenerative 

disorders and to studies that examine associations and effects in humans on neurodegenerative 

disorders, there is a very broad range of related topics that have been studied. In an iterative 

process, the EPC worked with the TEP to focus the questions and the topics on those that are 

most likely to shed light on mechanisms of action and effects related to Alzheimer’s disease 

(AD), Parkinson’s disease (PD) and related neurocognitive disorders. Thus this report does not 

evaluate all mechanisms of action or all associations related to neurological function. Given the 

very large number of studies (both human and animal) related to B vitamins, and the small 

number of studies of berries, these caveats apply primarily to B vitamin topics. 

 The following topics were chosen, in consultation with the TEP, for evaluation: 

B Vitamins: Human Studies 

• Association between B vitamin treatment/intake with diagnosis of AD or PD, cognitive 

function, or histopathology (primary prevention of disease) 

• Association between B vitamin treatment/intake with severity of AD or PD, cognitive 

decline, or histopathology. (secondary prevention/treatment) 

• Association of B vitamin levels and AD or PD diagnosis, or histopathology 

• Association of B vitamin levels and AD or PD severity 

• Association of B vitamin levels and cognitive function 

B Vitamins: Animal / In Vitro Studies 

• Effect of B vitamin supplementation or deficiency on cognitive function, movement 

disorders, histopathology, L-dopa and pre-cursor levels, etc., in appropriate models 

• Effect of B vitamins on the expression or function of AD-related genes (presenilin, alpha2 macroglobulin, amyloid precursor protein, Apo E4) 

• Blood brain barrier function in relation to B vitamins 

• Cerebrovascular endothelial function in relation to B vitamins 

 Thus, the following potential topics (among others) are not reviewed: B vitamin-dependent 

enzyme levels or function; markers of inflammation or other potential causes of neurocognitive 

decline, including homocysteine, except as they relate to the association between B vitamins and 

neurocognitive status; B vitamin megadose-related toxicity; animal studies using B vitamin 

antagonists, brain lipid metabolism, animal perinatal and growth-related brain/nerve/cognition 

development; genes related to B vitamin function or enzymes such as MTHFR; GABA 

metabolism, or neuron ion channels. 

Berries. Given the small size of the relevant literature, all studies evaluating the effect or 

association of berries or constituents of berries with any neurological or cognitive outcome were 

included. 

Eligibility Criteria 

 This report encompasses evaluations of both clinical human studies and basic science studies 

performed in animal and in vitro models. Therefore, specific eligibility criteria were needed for 
20

each topic. We first describe the common eligibility criteria for any study included in this report, 

followed by additional specific criteria for each topic. 

Human Studies. The common inclusion criteria for human studies analyzed in this report 

consist of primary studies; English language publication, human adult subjects; analysis of the 

predictor or description, including quantification, of the intervention, and analysis of the 

following categories of outcomes: diagnosis or severity (degree) of AD, PD, other age-related 

neurocognitive disorder, or cognitive impairment; test of cognitive function. We excluded 

studies of mental retardation, including Down syndrome, Wernicke’s encephalopathy, subacute 

combined degeneration, vascular dementia, acute encephalopathy, and mixed causes of dementia 

lacking separate analyses for disease types. Also excluded were studies of peripheral neuropathy 

and other lower motor neurodegeneration not related to PD. However, studies that compared 

groups of patients with age-related neurocognitive disorders with groups of patients with other 

dementias were included. We also excluded case reports and studies of non-applicable 

populations, such as young patients with diabetes. Abstracts without an associated full report 

were excluded. Where studies were reported in multiple publications, the more completely 

reported and/or the report with the longer duration of follow-up were used; although data from 

multiple publications of the same study may be combined.

Animal / In Vitro Studies. Animal and in vitro studies had to be published in full form, 

excluding abstracts, in English language journals. We included all animal and in vitro models of 

diseases of interest and all outcome measurements related to the outcomes and/or associations of 

interest. We excluded studies that used inappropriate animal or in vitro models, such as immature 

animals and non-neuronal cells.

B Vitamin Topics 

Common criteria. The following B vitamins were investigated: 

• B1 (thiamine) 

• B2 (riboflavin) 

• B6 (pyridoxine and related compounds) 

• B12 (cyanocobalamin) 

• Folate 

We included evaluations of the single vitamins and combinations of the B vitamins. We 

excluded evaluations of “multivitamins” that included vitamins other than B vitamins. 

Evaluation of B vitamins could be from supplements (given by any route), food sources, or 

specific tissue concentrations. Evaluated body levels included blood, serum, plasma, 

cerebrospinal fluid, or tissue sample (including red blood cell) levels of the specific vitamins and 

commonly measured metabolites (i.e., pyridoxal-5’-phosphate, the active coenzyme form of B6, 

and thiamine pyrophosphate, the active coenzyme form of B1). We allowed any measurement 

methodology. We did not include other proxies for B vitamin levels (e.g., thiamine-dependent 

enzyme activity). 

Human intervention studies (trials). We included only prospective trials of clearly defined B 

vitamin interventions. We allowed randomized controlled trials (RCTs), prospective nonrandomized comparative trials, and prospective cohort studies (single arm studies without a 

control group). We allowed trials of both supplements and food sources. We excluded studies of 
21

the effect of B6 intake on Parkinsonian symptoms and L-dopa levels in patients using L-dopa 

treatment. (This issue is discussed in the adverse events section of the results.) 

Human association studies. Among studies that reported associations between B vitamin levels 

and neurocognitive outcomes, we included only those that included subjects with either AD or 

PD, or neurocognitive impairment, excluding studies focusing on cognitively normal 

populations. All studies, regardless of sample size, were included regarding PD or vitamins B1, 

B2, or B6 levels. For cross-sectional studies of either B12 or folate levels and subjects with 

either AD or cognitive impairment, we included only studies that evaluated both at least 100 

subjects total and 30 subjects with AD or cognitive impairment (not including vascular dementia, 

mental retardation, etc.). However, we included all longitudinal studies, regardless of sample 

size. 

 For studies evaluating B vitamin intake (i.e., by food frequency questionnaires), we included 

only studies with at least 50 subjects. We chose this arbitrary threshold to as a minimum number 

of subjects required to ensure adequate power for associations to be investigated in these 

retrospective studies. Studies of food intake (from food frequency questionnaires) must have had 

comparison groups of subjects with different levels of neurocognitive function. In addition we 

excluded cross-sectional intake studies that examined only dietary intake of patients with 

dementia. These studies evaluated nutritional deficiencies caused by poor diet due to dementia, 

which was not considered to be of interest. 

 For both human intervention and association studies, we did not include evaluations of 

outcomes related to depression, other psychiatric conditions, sleep, appetite, or other somatic 

conditions. We evaluated only diagnoses or measures of cognitive function or symptoms of PD. 

Animal / in vitro studies. We excluded animal or in vitro models specific to Wernicke’s 

encephalopathy; namely models of thiamine deficiency combined with ethanol. Although, if 

sufficient data regarding thiamine deficiency without ethanol was also included, these studies 

were reviewed. We also excluded animal and in vitro models that caused or exacerbated B 

vitamin deficiency with B vitamin antagonists. In addition, “case reports” or “case series” of B 

vitamin deficiencies in farm animals were excluded. 

Berry Topics 

Common criteria. After reviewing various definitions of berries and in consultation with the 

TEP, the following berries were included: 

• Bilberry 

• Black raspberry 

• Blackberry 

• Blueberry 

• Boysenberry 

• Cranberry 

• Currants 

• Gooseberry 

• Lingonberry 

• Marionberry 

• Raspberry 

• Strawberry 
22

 We recognized that these common terms for berries do not always match one-for-one with 

specific species. We allowed all fruits that are commonly designated among these berries. We 

included studies that used whole berries or specific constituents of berries. We did not include 

studies that evaluated constituents found in berries that were not derived from berries (e.g., 

purified quercetin). 

Human studies. We included any study that examined the effect of or association between 

berries and any neurocognitive outcome in any population. 

Animal / in vitro studies. We exclude studies using amphetamine- or lithium chloride-induced 

conditioned taste avoidance (CTA) as rats’ learning or behavioral outcome. The CTA paradigm 

measures the avoidance by rats of a sucrose solution that has been paired with a high dose of a 

drug, such as amphetamine. The LiCl is used as a control. “Learned safety” theory is the 

mechanism of CTA results;31 it is not related to age-related cognitive or behavioral function. 

Other Topics 

Constituents in berries. Regarding the berry Key Question 1 on the constituents in berries 

related to neurological effects, we evaluated introduction and discussion sections from articles 

reviewed for other berry topics and also searched for both systematic and general reviews of the 

topic. 

Adverse events. For both B vitamins and berries we included any adverse event data from 

otherwise evaluated human studies. We also reviewed other human studies that did not meet 

criteria for inclusion for other topics. In addition, we searched for both systematic and general 

reviews regarding adverse events in humans. We included all systematic reviews. General 

reviews were included on an ad hoc basis, depending on generalizability and adequacy of source 

material. We excluded adverse events related to pregnancy, children, contraception, cancer, and 

specific drug interactions (methotrexate, colon cancer chemotherapy, etc.). For berries, we also 

excluded allergies and issues related to food contaminants. 

Literature Search Strategy 

 We conducted a comprehensive literature search to address the key questions.* Final 

literature searches for English language publications on B vitamins were conducted in 

MEDLINE® and the Commonwealth Agricultural Bureau (CAB) AbstractsTM on February 2, 

2005 and for berries, in the same databases, on March 3, 2005. Search terms included subject 

headings and textwords with filters to limit the publications to English language. Subject 

headings and text words were selected so that the same set could be applied to both databases. 

The searches included both human, animal, and in vitro studies. Among the articles in 

MEDLINE®, specific article types were excluded, such as editorials, letters, and case reports, and 

other types that would not meet eligibility criteria. 

 

* Appendixes cited in this report are provided electronically at 

http://www.ahrq.gov/downloads/pub/evidence/pdf/berry/berry.pdf.
23

 Both the B vitamin and berry searches used a common neurocognitive model that included 

the following terms: nervous system diseases, cognitive disorders, neurodegeneration, dementia, 

Alzheimer, Parkinson, Lewy body, neuron/nerve cells, brain, and related terms. 

 The B vitamin search included both common and chemical names for all the B vitamins of 

interest. The berry search included both common and botanical names for all the berries of 

interest and the term “fruit,” excluding “fruit fly.” In addition, we included a list of 33 chemical 

terms for known berry constituents. 

 Additional studies were sought by contacting members of the TEP, and from reference lists 

of selected included articles and review articles and meta-analyses. Although the large majority 

of evidence regarding berries was from a single group of investigators, the decision was made 

with the TEP to maintain the restriction of eligible literature to published, peer-reviewed articles. 

 

Study Selection and Data Extraction 

 All citations identified through the literature search were screened according to the inclusion 

criteria. A low threshold for acceptance was used at this stage to maximize the retrieval of 

potentially useful studies. Retrieved articles were evaluated against the complete inclusion 

criteria. 

 A single reviewer extracted each eligible study.*

 Data extraction problems were addressed 

during weekly meetings. Occasional sections were re-extracted to ensure that uniform definitions 

were applied across extracted studies. Problems and corrections were noted through spot checks 

of extracted data and during the creation of summary and evidence tables. A second reviewer 

independently verified the data in the summary tables using the original article. 

Data Extraction 

 The same data extraction forms were used for both the B vitamin and berry articles. 

Human Studies. Two data extraction forms were created for human studies; one for 

interventions, and one for associations. These forms were designed in the format of an evidence 

table to allow simple conversion to these tables. In both forms, items extracted included: factors 

related to study characteristics (study design, duration, country, setting, funding source), 

population (age, sex, race), eligibility criteria, definitions of neurocognitive disorders, study 

sample (number enrolled, number analyzed, reasons for dropout), descriptions of interventions or 

predictors and of outcomes, limitations, comments, and an assessment of both study quality and 

applicability (see below).

 Intervention forms also captured results data related to baseline, follow-up, change, and net 

change in outcomes, along with standard deviation or standard error and statistical significance. 

Association forms captured results data related to mean outcome values of different groups, 

correlation values (r, odds ratio, relative risk, hazard ratio, etc.), and statistical significance of 

either differences or associations. 

 

* Appendixes cited in this report are provided electronically at 

http://www.ahrq.gov/downloads/pub/evidence/pdf/berry/berry.pdf.
24

Animal and In Vitro Studies. Animal and in vitro studies are usually designed to examine the 

proposed mechanisms or pathways for the observed effects of a substance on defined diseases or 

conditions in humans. These studies are generally not meant to provide precise estimates of 

effects, but instead to test alternative hypotheses. Therefore, the process in reviewing animal and 

in vitro studies is different than reviewing human clinical or epidemiological studies. In contrast 

to traditional systematic reviews of human studies where large heterogeneity across studies 

related to different models and outcomes being examined can be problematic, in basic science 

studies heterogeneity (such as different models) across studies is essential to test and eliminate 

alternative hypotheses (such as different outcomes), so long as the central hypothesis (e.g., the 

physiological application) is related.

 Thus, the goal of data extraction for these articles was not to extract the exact quantitative 

findings of each study. Instead, we extracted the following information to capture the concepts of 

importance. Namely, 

• What is the central hypothesis or stated purpose of the study? 

• What is the authors’ assessment of the gap between what is known and unknown? 

• What is the working model used in the study? 

• What is the study design (including characteristics, intervention, comparator, and 

outcomes, sample size, duration)? 

• What are the measurements or outcomes? 

• What are the results and authors’ conclusions? 

• What is the quality (including limitations) of the study? 

Grading of the Evidence 

 Studies accepted in evidence reports have been designed, conducted, analyzed, and reported 

with varying degrees of methodological rigor and completeness. Deficiencies in any of these 

components can lead to biased reporting and interpretation of the results. While it is desirable to 

grade individual studies to highlight the degree of potential bias, the grading of study quality is a 

challenging process. Most factors commonly used in quality assessment of RCTs do not 

demonstrate a consistent relationship to estimates of treatment effects.32 Thus, there is still no 

uniform approach to grade studies. For human studies of both B vitamins and berries, our EPC 

has adopted the following approach, as used in previous evidence reports. 

Methodological Quality Grade (Human Studies) 

 We used a 3-category grading system (A, B, C) to denote the methodological quality of each 

study. This grading system has been used in most of the previous evidence reports from the 

Tufts-NEMC EPC as well as in evidence-based clinical practice guidelines.33 This system 

defines a generic grading system that is applicable to varying study designs including RCTs, 

non-randomized comparative trials, cohort, and case-control studies: 

A Category A studies have the least bias and results are considered valid. A study that 

adheres mostly to the commonly held concepts of high quality including the following: 

clear description of the population, setting, interventions and comparison groups; 

sufficient power (arbitrarily defined as minimum sample size of 10 subjects); clear 
25

description of the content of the intervention or predictor used; appropriate comparator; 

appropriate measurement of outcomes; appropriate statistical and analytic methods and 

reporting; no reporting errors; less than 20% dropout; clear reporting of dropouts; and no 

obvious bias. Intervention trials must be double-blinded RCTs. Correlation analyses must 

use prospectively gathered data and must perform appropriate adjustment for potential 

confounders. 

B Category B studies are susceptible to some bias, but not sufficient to invalidate the 

results. They do not meet all the criteria in category A because they have some 

deficiencies, but none likely to cause major bias. The study may be missing information, 

making it difficult to assess limitations and potential problems. 

C Category C studies have significant bias that may invalidate the results. These studies 

have serious errors in design, analysis or reporting, have large amounts of missing 

information, or discrepancies in reporting. Specific criteria included large (>20%) or 

unequal dropout rate, large discrepancy in baseline and final numbers of subjects, nonrandomized or single-cohort intervention studies, dissimilar baseline values among 

cohorts, unclear duration or numbers of subjects, missing baseline data, or irreconcilable 

apparent differences between data in figures, tables, and text. 

In addition, cross-sectional association studies (between vitamin B level and either 

diagnosis or cognitive test score) that did not adjust for any potential confounders (i.e., 

performed only univariate analyses without relevant sub-analyses). 

 Methodological quality scoring was performed near the end of the review when we had the 

most experience and knowledge about the included studies. Each included study was graded by 

at least 2 people (with the exception of studies with major deficiencies, such as a noncomparative study design). When there were disagreements, 1 or 2 additional reviewers graded 

the studies and consensus was reached. Approximately half the studies had quality scoring by 3 

or more reviewers. 

Methodological Quality Grade (Animal / In Vitro Studies) 

 Although we used the same 3-category grading system (A, B, C) to denote the 

methodological quality of each study, the criteria used to assess the methodological quality of 

animal or in vitro studies are different from those used for human studies. Compared to human 

clinical trials, randomization of treatments and blinded analysis may be essential, but is often not 

applicable to animal or in vitro experiments. Therefore, we did not incorporate these factors into 

our quality grading system. This system defines a generic grading system that is applicable to 

both animal and in vitro studies: 

A Category A studies have the least bias and results are considered valid. A study should 

report comprehensive background information on animals or cell lines used. For animals, 

the information should include the animal source, strain, sex, age, body weight, housing 

condition (diet, light/dark cycle, number of animals per cage), and experimental 

environment (ambient temperature, time of day, and season). For cell lines, the 

information should include the origin, growth media, and experimental environment. The 
26

number of animals in the experiments and animals excluded from a study, and the 

reasons for their exclusion, must be reported. Controls should be contemporary and 

preferably be approximately equal in group size to the intervention groups. Treatments 

(e.g., the compositions of experimental and control diets) and outcome measures should 

be clearly defined and reported. Experimental models should be independent of each 

other. All experiments should have at least one repetition. 

B Category B studies are susceptible to some bias, but not sufficient to invalidate the 

results. They do not meet all the criteria in category A because they have some 

deficiencies, but none likely to cause major bias. The study may be missing information, 

making it difficult to assess limitations and potential problems. 

C Category C studies have significant bias that may invalidate the results. These studies 

have serious errors in design, analysis or reporting, have large amounts of missing 

information, discrepancies in reporting or irreconcilable apparent differences between 

data in figures, tables, and text. 

Applicability Grade 

 Only human studies were assessed for applicability. For animal and in vitro studies, no 

assessment was made as to the applicability of the experimental model. 

 Applicability addresses the relevance of a given study to a population of interest. Every study 

applies certain eligibility criteria when selecting study subjects. Most of these criteria are 

explicitly stated (e.g., disease status, age, sex). Some may be implicit or due to unintentional 

biases, such as those related to study country, location (e.g., community vs. specialty clinic), or 

factors resulting in study withdrawals. The question of whether a study is applicable to a 

population of interest (such as Americans) is distinct from the question of the study’s 

methodological quality. For example, due to differences in the background diets, an excellent 

study of Japanese men may be very applicable to people in Japan, but less applicable to Japanese 

American men, and even less applicable to African American men. The applicability of a study 

is thus dictated by the questions and populations that are of interest to those analyzing the 

studies. 

 In this report, the focus is on individuals at increased risk for, or diagnosed with, age-related 

neurocognitive disorders; in particular AD or PD. Even though a study may focus on a specific 

target population, limited study size, eligibility criteria, and the patient recruitment process may 

result in a narrow population sample that is of limited applicability, even to the target population. 

To address this issue, we categorized studies within a target population into 1 of 3 levels of 

applicability that are defined as follows: 

 

ddd Sample is representative of the target population. It should be sufficiently large to 

cover both sexes, an appropriate age range, and other important features of the 

target population (e.g., general health status). At least 30 subjects analyzed. 

dd Sample is representative of a relevant sub-group of the target population, but not 

the entire population. Limitations include such factors as narrow age range, single 
27

ethnicity, setting that applies to only a portion of the population (e.g., nursing 

home). At least 10 subjects analyzed. 

d Sample is representative of a narrow subgroup of subjects only, and is of limited 

applicability to other subgroups. For example, a study of the oldest-old men or a 

study of a population on a highly controlled diet. 

Reporting Results 

Outcomes Reported 

 For both human intervention studies and animal / in vitro studies we evaluated all outcomes 

relevant to neurocognitive function that were reported in studies. However, for human 

association studies regarding cognitive function, in consultation with the TEP, we focused the 

detailed evaluation to a limited number of outcomes. A large number of tests of cognitive 

function have been used by different study groups. Few of these have been validated in any 

systematic way. Interpretation of tests used by single groups or that have not been validated can 

be problematic. Thus we evaluated in detail the following tests of cognitive function: 

• Mini-mental status examination (MMSE) and modifications 

• Alzheimer’s Dementia Assessment Scale (ADAS) 

• Mattis’ Dementia Rating Scale (DRS) 

• Wechsler Adult Intelligence Scale (WAIS) 

Other cognitive tests are summarized qualitatively only. All relevant outcomes in studies of 

patients with PD are reported in detail, as are all associations between B vitamin levels and 

diagnoses of cognitive disorders. 

Metrics Included 

Human Intervention Trials. For controlled intervention trials the summary tables describe 3 

sets of data: the mean baseline levels in both intervention and control arms, within-cohort 

changes (e.g., InterventionFinal – InterventionInitial), the net change of the outcome, and the 

reported P values of both the within-cohort change and the net change. The net change of the 

outcome is the difference between the change in the intervention arm and the change in the 

control arm:

Net change = (InterventionFinal – InterventionInitial) – (ControlFinal – ControlInitial). 

For non-controlled interventions, we report the within-cohort changes and P values. For both 

types of studies we did not calculate any P values, but, when necessary, used provided 

information on the 95% confidence interval or standard error (SE) of the net difference to 

determine whether it was less than 0.05. We included any reported P value less than 0.10; those 

above 0.10 and those reported as “non-significant” were described as “NS” (non-significant) in 

the tables. 

Human Association Studies. For studies reporting mean B vitamin levels, mean cognitive 

function scores, or prevalence of disease in different groups of patients, these values are included 

in summary tables along with reported P values of differences among the groups. For studies that 

reported further analyses, such as odds ratio or relative risk, or correlation (r) between, for 
28

example, B vitamin level and cognitive test score, these values are reported, along with their 

statistical significance. When available, both unadjusted and adjusted values are included. 

Animal / In Vitro Studies. Numerical results are not reported for the basic science studies. We 

aimed to capture the direction and the statistical significance of all outcomes. For each analysis 

we report a symbol for the effect and the statistical significance (when reported). We used the 

following symbols:

+ Normal B vitamin animals/tissue performed better than B vitamin-deficient 

 animals/tissue, or

Berry-fed animals/tissue performed better than non-berry-fed animals/tissue 

0 No difference in performance 

— Normal B vitamin animals/tissue performed worse than B vitamin-deficient 

 animals/tissue, or

 Berry-fed animals/tissue performed worse than non-berry-fed animals/tissue 

The assessment of whether animals or tissue receiving the intervention performed better than 

controls was made based on a combination of the reported results, the statistical significance, and 

the conclusions of the authors. 

Units. For measures of B vitamin levels, the original units reported in the study were included in 

the evidence tables. However, all such measurements were converted to standard units (e.g., 

mg/dL) in the summary tables to facilitate comparisons. 

Evidence and Summary Tables 

 The evidence table offers a detailed description of the studies that addressed each of the key 

questions. The evidence table is available via the internet.*

 The tables provides all the 

information that was extracted from each study (as described above, under Data extraction). 

Each study appears once regardless of how many interventions or outcomes were reported. The 

evidence tables of human studies are ordered alphabetically by the first author, then by 

publication date. The evidence tables of animal and in vitro studies are categorized by topic and 

ordered chronologically, so as to capture the sequence of the research. 

 Summary tables are included in each Results section. They succinctly report summary 

measures of the main outcomes evaluated. They include information regarding study duration (as 

applicable), study size, intervention and control, outcomes, results, methodological quality, and 

study applicability. They are designed to facilitate comparisons and synthesis across studies. 

Studies reporting multiple predictors (e.g., B vitamins) may appear several times in summary 

tables. Blank cells indicate that the relevant data were not reported in the articles. 

 Studies that did not report detailed reports of interest to this report are included in the 

summary tables. The qualitative results – whether a significant or non-significant association – 

are included either as a paraphrase of or direct quote from the authors. 

 Within summary tables of human studies, studies were ordered first by outcome test (for 

cognitive tests: MMSE, ADAS, DRS, WAIS, then others), then from highest quality to lowest, 

then from highest applicability to lowest, then from largest to smallest number of subjects. 

Summary tables of animal and in vitro studies are ordered chronologically. 

 

* Appendixes cited in this report are provided electronically at 

http://www.ahrq.gov/downloads/pub/evidence/pdf/berry/berry.pdf.
29

Adverse Events Reporting 

 We used the term adverse event as defined by the World Health Organization (WHO) 

International Conference on Harmonization. An adverse event is “any untoward medical 

occurrence in a patient or clinical investigation subject administered a pharmaceutical product 

and which does not necessarily have to have a causal relationship with this treatment. An adverse 

event can therefore be any unfavorable and unintended sign (including an abnormal laboratory 

finding, for example), symptom, or disease temporally associated with the use of a medicinal 

product, whether or not considered related to the medicinal product.” An adverse drug reaction is 

any “noxious and unintended response to a medicinal product related to any dose...” 

(www.fda.gov/cder/guidance/iche2a.pdf). 

 We reviewed all accepted and rejected human studies of either B vitamins, berries, or berry 

constituents being used as an intervention for data on adverse events and drug interactions. These 

reports included randomized trials, cohorts, case-control studies, and individual case reports and 

series. We excluded allergies (except for anaphylaxis) and occupational exposures. 

 Since adverse event reporting was very limited among the reviewed studies, we also 

performed searches for both systematic reviews and review articles regarding adverse events due 

to either B vitamins or berries. We also performed a search of articles on berries that have been 

tagged by MEDLINE® or CAB AbstractsTM as addressing adverse events.

31 

Chapter 3. Results 

B Vitamins 

 In this section, we summarize the results from human and animal or in vitro studies of the 

B vitamins – B1 (thiamine), B2 (riboflavin), B6 (pyridoxine and related chemicals), B12 

(cobalamin), and folate – in relation to age-related neurodegenerative disorders (primarily 

Alzheimer’s disease [AD] and Parkinson’s disease [PD]). The three Key Questions to be 

answered are as follows: 

1. What is the evidence regarding mechanisms of action of the B vitamins B1, B2, B6, B12, 

and folate (singly and in combination) for preventing, decreasing the rate of progression 

of, or reversing the neurological changes associated with age-related neurodegenerative 

conditions such as Parkinson’s or Alzheimer’s disease? 

2. What is the evidence that the B vitamins B1, B2, B6, B12, and folate can prevent, 

decrease the rate of progression of, or reverse the neurological changes associated with 

age-related neurodegenerative conditions such as Parkinson’s or Alzheimer’s disease in 

humans 

3. What adverse events in humans have been reported in the literature for supplementation 

with the B vitamins B1, B2, B6, B12, and folate? 

a. Do the frequency of adverse events vary with source, dose, or other evaluated 

factors? 

 Findings are presented in the order of the Key Questions. 

 The final search of MEDLINE® and CAB AbstractsTM yielded 6,640 citations. This search 

included human, animal, and in vitro studies. After screening of the titles and abstracts, 183 

articles on human studies and 87 articles on animal or in vitro studies. An additional 15 human 

studies and 1 animal study were found from review articles, study reference lists, and domain 

experts. From these, 83 human studies and 27 animal or in vitro studies were included in this 

review. However, though the review covers both neurocognitive function related to AD and 

related diseases and the movement disorders and motor systems degeneration related to PD and 

related diseases, only scant evidence was found regarding PD-related conditions. 

 Qualifying studies are presented in summary tables in the appropriate sections. Details 

regarding all included studies are available in the evidence tables.*

 

Animal and In Vitro Studies: Mechanisms of Action 

 All studies related to mechanisms of action of B vitamins have been performed in animal or 

in vitro models. A total of 17 studies were included in this section. Of these, 10 examined the 

 

* Appendixes cited in this report are provided electronically at 

http://www.ahrq.gov/downloads/pub/evidence/pdf/berry/berry.pdf.
32 

effects of B vitamins on animals’ cognitive function, movement disorders and brain 

neurotransmitters or histopathology (Tables 2-5). Only one in vitro study and one animal study 

with three publications examined the effects of B vitamins on the expression or function of ADrelated genes. Five studies examined the effects of B vitamins on the blood brain barrier (BBB) 

or cerebrovascular endothelial function (Table 6). 

Effects of B Vitamins on Cognitive Function, Movement Disorders, 

and Brain Neurotransmitters or Histopathology 

Study Descriptions. The effects of B vitamins on cognitive function, movement disorders and 

brain neurotransmitters or histopathology in animal and in vitro models were described in 10 

studies in 11 publications.26,27,34-42 Four studies in five publications used thiamine deficient 

models in rats. Three studies were of moderate quality, and one was of poor quality (Table 2). 

Two examined the effects of B6 treatments on animals’ performances in neurocognitive tests. 

One was of high quality and the other one was of moderate quality (Table 3). One high quality 

study used models of vitamin B12 supplementation in rats.(Table 4). Three studies used folate 

deficient models alone or in combination with PD or AD models in mice or rats. Three studies 

were of high quality and one of moderate quality (Table 5). We found no study that examined the 

effects of riboflavin (vitamin B2) or mixed vitamin B treatments on outcomes of interest.

Overall Effects 

Thiamine (B1). The overall findings of the effects of thiamine deficiency are summarized in 

Figure 1. Of the four studies (in five publications) using thiamine-deficient models, two 

examined the rats’ clinical status and/or histopathology after 44 days or 35 weeks of thiaminedepleted diets, and three examined rats’ performance in neurocognitive tests (Table 2).34-36,38,39

The two studies that examined the rats’ clinical status and/or histopathology found that a diet 

without thiamine significantly damaged the rats’ brains and/or caused serious neurological 

pathology, including death. In the other two studies that examined the effects of thiamine 

deficiency on rats’ performance in neurocognitive tests, the deficient regimens varied widely. 

Specifically, Terasawa 1999 fed the rats a low-thiamine diet (30 mg per 100 g diet) for 

approximately 42 days, and Ciccia 2000 fed the rats a vitamin-fortified chow in combination 

with a thrice-weekly thiamine injection (1 mg per kg body weight) for three episodes of thiamine 

deficiency. Each episode lasted about 4.5 weeks. Terasawa 1999 found rats fed thiaminedeficient diets had significantly impaired performances in the neurocognitive tests when 

compared to the control rats. Ciccia 2000 found that rats with three separate episodes of thiamine 

deficiency had significantly impaired performance in two of eight neurocognitive tests. 

Pyridoxine (B6). Two studies used a vitamin B6-supplementation model in mice or rats and both 

studies examined different doses of B6 supplementation on performances in neurocognitive tests 

(Table 3).41,42 No significant effects of B6 supplementation were found for rat learning or 

cognitive function. Dietary B6 supplementations showed some positive effect on motor function 

or behavior, although the effects were not consistent across the two studies. The studies did not 

find a linear dose-response relationship for the effects; however, the results suggested worse 

motor function was associated with a lower dose of dietary B6 supplementation.

Cyanocobalamin (B12). One study examined the effects of low-dose vitamin B12 

supplementation on spontaneous movements and performance in the Morris Water Maze in rats 
33 

with nucleus basalis magnocellularis (NBM) lesions (an animal model that mimics some of the 

cholinergic hypofunction and memory loss associated with AD; Table 4).37 The study found that 

low dose (1 mg per kg diet) vitamin B12 supplementation alone had no significant effect on 

spontaneous movements and did not improve memory in rats with NBM lesions. 

Folate. Three studies examined the effects of folate deficiency on animal performance in 

neurocognitive tests and on brain neurotransmitters or histopathology; two used a normal animal 

model, one used a PD model and one used an AD model (Table 5).26,27,40 Kim 2002 conducted a 

electron microscopic experiment comparing the cerebrocortical microvascular wall in brain cross 

sections with rats fed a diet without folate to that of rats fed a diet with folate (4 mg per kg diet). 

After 8 weeks of dietary treatments, a degenerative appearance of the cerebrocortical 

microvascular wall occurred in rats fed folate-deficient diet, while rats fed a diet with folate had 

a normal cerebral capillary wall. Duan 2002 tested the effects of folate deficiency using a rat 

model of PD. After 3 months of dietary treatments, both experiment and control animals received 

two intraperitoneal injections of 20 mg 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) 

per kilogram body weight. The MPTP toxin induced PD-like pathology and behavioral 

symptoms. In contrast to mice on the control diet that were resistant to the sub-toxic dose of 

MPTP, mice maintained on the folate-deficient diet exhibited profound motor dysfunction as 

indicated by a decrease in the period of time in which they were able to maintain themselves on 

the rotarod and by an increased number of falls. However, folate deficiency alone did not impair 

rats’ performance on rotarod tests. Kruman 2002 examined the effects of folate deficiency on 

brain histology findings in amyloid precursor protein (APP) mutant mice. These mice developed 

age-dependent deposition of amyloid β-peptide in their brains. There was no significant 

difference in the levels of amyloid β deposition between APP mutant mice on the folate-deficient 

diet and those on the control diet. However, the analyses in the CA3 region of the hippocampus 

revealed a highly significant 20 percent loss of neurons in APP mutant mice on the folatedeficient diet compared with those on the control diets. These results suggested that folate 

deficiency renders hippocampal CA3 neurons in APP mutant mice vulnerable to death by a 

mechanism that does not involve increased amyloid β production or deposition. 

Summary. Of the four studies that used thiamine-deficient models, two examined the rats’ 

clinical status and/or histopathology after thiamine-depletion diets and all found that thiaminedepletion diets significantly damaged brain and/or cause serious neurological pathology, 

including death. The remaining two studies that examined rat performance in neurocognitive 

tests found that thiamine deficiency had significantly impaired performance in some 

neurocognitive tests. 

 Two studies used a B6-supplementation model in mice or rats to examine the effects of B6 

treatments on performance in neurocognitive tests. Both studies that used the B6-

supplementation model examined various doses of B6 supplementation on animal performance 

in neurocognitive tests. No significant effects of B6 supplementation were found on rats learning 

or cognitive function. Dietary B6 supplementations showed some positive effect on animal 

motor function or behavior, although the effects were not consistent across the two studies and 

did not show a linear dose-response relationship. 

 One study showed that low dose (1 mg per kg diet) vitamin B12 supplementation alone had 

no significant effect on spontaneous movements and did not improve memory in rats with NBM 

lesions. 
34 

 Of the three studies that examined the effects of folate deficiency on animal performance in 

neurocognitive tests and brain neurotransmitters or histopathology, two used a normal animal 

model, one each used a PD model and an AD model. Results from the normal animal model 

showed a degenerative appearance of the cerebrocortical microvascular wall was shown in rats 

fed a folate-deficient diet for 8 weeks, but 3-month folate-deficient diet did not impair rats’ 

performance on rotarod tests. The one study that tested the effects of folate deficiency using a rat 

model of PD found that mice which had been maintained on the folate-deficient diet exhibited 

profound motor dysfunction induced by MPTP, in contrast to mice on the control diet that were 

resistant to the sub-toxic dose of MPTP. The results from the one study that used an AD model 

to examine the effects of folate deficiency on brain histology findings in APP mutant mice 

suggested that folate deficiency renders hippocampal CA3 neurons in APP mutant mice 

vulnerable to death by a mechanism that dose not involve increased amyloid β production or 

deposition. 

 We found no study that examined the effects of riboflavin (B2) or mixed B vitamin 

treatments on outcomes of interest. 

 Overall, research has shown that there were negative effects of thiamine and folate deficiency 

or deprivation on animal’s clinical status and/or histopathology, although not all deficient 

animals had worse performance in neurocognitive tests. Studies have found some positive effects 

of the supplementations of B6, B12, and folate on animal’s performance in neurocognitive tests, 

but studies did not show a dose-response relationship. Only folate deficiency was examined in 

animal models of AD and PD; the results showed a synergistic effect with both PD and AD 

pathology. 

Summary Findings From Studies Using Immature Animals. Eight studies in nine 

publications were not included in detail in this review because immature rodents were used.43-51

In these studies, young rodents were treated for a short period time and tested before their growth 

ceased. Though these studies are not applicable to questions concerning “age-related 

neurodegenerative” changes, it is of interest how these studies compare to those with more 

appropriate models. Of the eight studies, three used thiamine-deficient models, two used B6-

deficient models, two used a B12-supplementation model, and one used folate-deficient model. 

The results from these studies were similar to those summarized in this report. Detailed data can 

be found in the evidence tables.*

 

 

* Appendixes cited in this report are provided electronically at 

http://www.ahrq.gov/downloads/pub/evidence/pdf/berry/berry.pdf.
35 

Figure 1. Summary findings of the effects of thiamine deficiency on rats’ cognitive function, movement 

disorders and brain histopathology 

Thiamine

deficiency

Bain

histopathology or

neuronal damages

+(2)

Neurological pathology +(2) +0(1)

Death or moribund +(1, 2)

Time to lever press to stop aversive

electrical stimulation +(3)

Response time of spontaneous activity 0(4)

Spontaneous alternation 0(4)

NMTP acquisition trials 0(4)

Delayed NMTP trials 0(4)

Reversal learningMTP 0(4)

Delayed MTP trials +(4)

2nd reversal learning 0(4)

References: Overall task failure rate +(4)

(1) Jolicoeur, 1979

(2) Zimitat, 1990

(3) Terasawa, 1999

(4) Ciccia, 2000 Clinical signs of neurological or behavioral

disturbances +(4)

+ Normal thiamine animals performed better than thiamine-deficient animals 

0 No difference between groups 

– Normal thiamine animals performed worse than thiamine-deficient animals 
36

Table 2. Thiamine deficient (intervention) vs. normal thiamine (control) diets Study, Year 

Model 

Age/Weight 

Duration Intervention (B1 dose) N Control (B1 dose) N Neurocognitive Test / Clinical Pathology Results P Hist

Mea

Neurological pathologyc followed by 

deaths 

+ <.05 Jolicoeur, 

1979 (2 papers) 

Rats 

Male 

Sprague 

Dawley, 

275-350 g 

44 

days 0 6 Purina Rat Chow (nd) 6 Catalepsy, rigidity, 

and landing foot spread 

0 

Zimitat, 1990 Rats 

Female 

Wistar, 

9 wk 

35 

wk 0 36 /11d 8 or 50 mg/kg of diete 36/17d Ataxia, opisthotonus, moribund + <.001 Hemor

necrosvacuol

Terasawa, 1999 Rats Wistar, 260-300 g ~42 days 30 mg/100 g of diet 5 60 mg/100 g of diet 5 Time to lever press to stop aversive electrical stimulation + nd 

Response time of spontaneous activity 0 Spontaneous alternation 0 NMTP acquisition trials 0 Delayed NMTP trials 0 Reversal learning MTP 0 Delayed MTP trials + <.0001 2nd reversal learning 0 Overall task failure rate + nd 

Ciccia, 2000 Rats 

Male Sprague Dawley, ~2 mo 

8 mo 

Vitamin-fortified 

chow + 

3 episodes of TD, 

each of which 

lasted ~4.5 wk at 

wk 10, 18, and 26 

of treatment 

~12f

Vitaminfortified 

chow + 

1 mg/kg BW 

i.p. 

3 times/wk 

(Monday, 

Wednesday, 

Friday) 

~14f

Clinical signs of neurological or behavioral disturbances 

+ nd 

Model=Animal, Strain; BW = body weight; i.p. = intraperitoneal; NMTP = nonmatching-to-position; MTP = matching-to-position; wk = week c Less locomotor activity, lost the righting reflex, displayed impaired weight shift responses d Number tested for clinical symptoms / Number tested for histopathology e Control group = 8 mg/kg, 2 thiamine fortified groups = 50 mg/kg. No difference among these groups f At different stages of behavioral testing, 5 control rats and 2 thiamine deficient rats either died of unknown causes or developed tumors and were killed. Thus, group 

behavioral task are different 

g Pathologies seen primarily in the medial vestibular nucleus 
37

+ Normal thiamine animals performed better than thiamine-deficient animals 0 No difference between groups – Normal thiamine animals performed worse than thiamine-deficient animals Table 3. Vitamin B6 supplementation (intervention) vs. normal B6 (control) diets in healthy animals 

Study, 

Year 

Model 

Age/Weight 

Duration Intervention (B6 dose) N Control (B6 dose) N Neurocognitiv e Test 

Groups 

3 μg/day B6-HCla 15 15 μg/day B6-HCla 20 

Active escape learning: mean score & variance 

All 

150 μg/day B6-HCla 15 

None Passive 

avoidance learning: mean score & variance 

All 

Locomotor 

activity: mean score 

All 

3 μg 

15 μg 

Tunnicliff, 1972 Mice 

Male C57BL/6J & DBA/2J inbred strain, 9 wk 

4 wk 

Locomotor 

activity: variance 150 μg 

15 μg/15 g diet 6 15 μg 30 μg/15 g diet 6 30 μg 45 μg/15 g diet 6 45 μg 60 μg/15 g diet 6 60 μg 75 μg/15 g diet 6 75 μg 90 μg/15 g diet 6 

Activity and 

curiosity 

90 μg 

Driskell, 1973 Rats 

Female, 220 g 3 wk None 6 

T maze All 

B6-HCl = pyridoxine hydrochloride; i.p.= intraperitoneal a The amount of B6 was estimated based on each animal drank approximately 5 mL of water and ate about 5 g of food each day 

+ B6 supplemented animals performed better than normal B6 (or reference) animals, or normal B6 animals performed better than B6-deficient animals 

0 No difference between groups – B6 supplemented animals performed worse than normal B6 (or reference) animals, or normal B6 animals performed worse than B6-deficient animals 
38

Table 4. Vitamin B12 supplements (intervention) vs. normal B12 (control) diets in diseased animals 

Study, 

Year 

Model 

Age/Weight 

Duration Intervention (B12 dose) N Control (B12 dose) N Neurocognitive Test 

Spontaneous movements Morris water maze – 

Acquisition 

Masuda, 1998 Rats Wistar w/ NBM 

lesions 

10-18 days 1.0 mg/kg 10 

Standard rat chow 

(0.001 mg/ 

kg B12) 

10 

Morris water maze – 

Retention 

i.p. = intraperitoneal; NBM = nucleus basalis magnocellularis; Model = Animal, Strain or cell + B12 supplemented animals performed better than normal B12 animals 0 No difference between groups – B12 supplemented animals performed worse than normal B12 animals 
39

Table 5. Folate deficiency (intervention) vs. normal folate (control) diets 

Study, Year Model Age/Weight Duration Intervention (folate dose) N Control (folate dose) N Neurocognitive test Results P Biochemic

Histolog

measure 

Deficient – normal animal modelKim, 2002 Rats’ brains 

Male 

Sprague 

Dawley, 

6 mo 

8 wk 0 8 4 mg folate/kg diet 8 

Degenerativappearance cerebrocortmicrovascuwall 

Rotarod apparatus (time) 0

Duan, 2002 Mice 

C57B1/6, 

2 mo, 

21-23 g 

3 mo 0 10 2 mg folate/kg diet 10 Rotarod apparatus 

(number of falls) 

0

Loss of dopaminergneurons in substantia nigra 

Deficient – Parkinson’s disease model

Rotarod apparatus (time) + <.01 

Duan, 2002 Mice 

C57B1/6 

2 mo / 

21-23 g 

3 mo 0 mg folate/kg diet + 2 i.p. MPTP (20 mg/kg B.W.) 10 

2 mg 

folate/kg diet 

+ 2 i.p. 

MPTP (20 

mg/kg B.W.) 

10 Rotarod 

apparatus (number of falls) 

+ <.01 

Loss of dopaminergneurons in substantia nigra 

Deficient – Alzheimer’s disease model

Aβ depositiAβ1-42/Aβ140 ratio Loss of neurons in regions CAof hippocampu

Kruman, 2002 Mice 

“Swedish” 

APP 

mutant, 

7 mo 

3 mo 0 mg folate/kg + 4.5 gm/kg Hcy diet nd 

Standard 

mouse diet 

(folate: nd; 

Hcy : 0 

mg/kg diet) 

nd 

Loss of neurons in regions CAof hippocampu

i.p. = intraperitoneal; Model=Animal, Strain; B.W.=body weight; APP=amyloid precursor protein; Hcy=homocysteine; Aβ=amyloid β-peptide; mo = months; wk = weeks 

+ Normal folate animals performed better than folate deficient animals 0 No difference between groups – Normal folate animals performed worse than folate deficient animals 
40 

Effects of B Vitamins on the Expression or Function of Alzheimer’s 

Disease-Related Genes 

Study Descriptions. Only one animal study with 3 publications52-54 and one in vitro study55

examined the effects of B vitamins on the expression or function of AD-related genes. Both are 

of high quality. 

Overall Effects. Shea et al. published a series of papers to test a hypothesis that deficiencies in 

apolipoprotein E gene (ApoE) function are associated with increased oxidative stress in the 

central nervous system (CNS). ApoE can promote neuronal survival and outgrowth and may play 

important roles in adaptive responses to aging and brain injury.11 The experiments were carried 

out by comparing the responses of transgenic mice lacking ApoE with those of normal mice of 

the identical genetic background to dietary oxidative stress induced by folate deprivation and by 

inclusion of excess iron in their diet. The mice used in this series of experiments were 

overlapped. (The source of this information was a personal communication with the authors.) 

Both transgenic mice and normal mice were fed either an experimental diet (without folate) or a 

control diet (with 4 mg folic acid per kilogram of diet) for 1 month; then harvested total CNS 

tissue was analyzed for thiobarbituric acid-reactive substances (TBARS, an end-point index of 

oxidative damage), and total antioxidant capacity in CNS. ApoE-deficient mice were found to 

have significantly increased TBARS when challenged with iron (which induces oxidation) in the 

absence of folate, in contrast to ApoE-deficient mice challenged with iron in the presence of 

folate and to normal mice, regardless of folate or iron status. Furthermore, antioxidant capacity 

was lower in ApoE-deficient mice receiving iron in the absence of folate compared to same mice 

receiving folate or compared to normal mice, regardless of folate status. These results suggest 

that the genetic deficiency of a complete absence of ApoE could be alleviated with 4 mg/kg body 

weight folic acid repletion for 1 month. This is proposed as a partial explanation as to why 

certain ApoE alleles are associated with increased prevalence and earlier onset of AD. 

 Fuso 2005 conducted an in vitro study using neuroblastoma cell lines and examined the 

effects of folate and vitamin B12 deficiency on AD gene and protein expression. Specifically, 

they examined APP, presenilin-1 (PS1) and presenilin-2 (PS2), the genes linked to familial AD.11

For the purpose of this review, we chose the most appropriate comparisons for our questions of 

interest, which were the results from cells grown in the vitamin deprived media versus cells 

grown in the differentiation media, because the only difference in the contents of these two 

media are the amount of folate and B12. The results showed that folate and vitamin B12 

deprivation did not change APP or PS2 gene and protein expressions, but increased PS1 gene 

and protein expression. 

Summary. A series of animal experiments showed that ApoE-gene knockout mice are less 

capable of buffering oxidative challenge in CNS than the normal mice, and the genetic 

deficiency of a complete absence of ApoE could be alleviated with folate repletion. The results 

from the other in vitro study demonstrated that an increase in PS1 gene could be induced by 

folate and vitamin B12 deprivation. The other genes involved in APP processing, and APP itself 

seemed to be independent of folate and vitamin B12 deprivation. 
41 

Effects of B Vitamins on Blood Brain Barrier or Cerebrovascular 

Endothelial Function 

Study Descriptions. Five studies on the effects of B vitamins on BBB or cerebrovascular 

enthothelial function are included in this section (Table 6).56-60 Of these, two moderate quality 

studies and one high quality study examined BBB transport and permeability in normal and 

thiamine-deficient rats. Two high quality studies examined the effects of dietary folate 

supplementation on cerebral endothelial function and cerebral vascular damage induced by 

hyperhomocysteinemia in vivo. 

Overall Effects 

Thiamine (B1) deficiency. Warnock 1968 examined pyruvate metabolism and the differences in 

pyruvate transport across BBB, comparing normal rats to thiamine-deficient rats.58 The results 

showed that labeled pyruvate entered the brain directly in adult thiamine-deficient animals, while 

it did not directly enter the brain of normal adult animals. This indicated that selective transport 

across BBB was not functioning in a normal fashion in thiamine-deficient rats. Robertson 1971 

evaluated the presence or absence of extravascular fluorescence bound to intraperitoneally 

administered bovine albumin in relation to the severity of BBB lesions.60 They found that 

extravascular fluorescence was present in one of 24 rat brains from animals with early stage of 

thiamine deficiency (as indicated histologically by slight edema, or more marked spongy 

reticulation, frequently accompanied by vascular congestion). Extravascular fluorescence was 

present in 12 of 22 rat brains from animals with late stage of thiamine deficiency (as indicated 

histologically by hemorrhages, tissue degradation and neuronal fallout). There was no 

extravascular fluorescence seen in rat brains from control animals. These results suggested that 

BBB is intact with respect to albumin in the early lesions of thiamine deficiency. Thus 

intracellular edema associated with early deficiency results from a defect in cell membrane 

transport rather than a vascular leak of the inflammatory type across BBB. A follow-up study by 

Manz 1972 employed a similar protocol to further define the nature and sequence of permeability 

changes of the BBB, using horseradish peroxidase (a low molecular weight protein marker).59 It 

was found that control rats and rats with early stages of thiamine deficiency had “qualitatively 

and quantitatively” the same pattern of peroxidase granules in phagocytes. None of the rats with 

early stage of thiamine deficiency had parenchymatous infiltration, while 21 of 30 rats with late 

stage thiamine deficiency did. Furthermore, control rats and rats with early stage of thiamine 

deficiency were devoid of peroxidase in the vascular basement membrane and the neural 

parenchyma. Although the interendothelial junctional complexes were morphologically intact in 

rats with late stage of thiamine deficiency, reaction product was deposited in the contraluminal 

side basement membrane zone of intercellular gaps. These results suggested that BBB damage 

seen in later stages corresponds to damage seen from cold-injury edema and other models of 

cerebral edema. The leakage of BBB appears to be predominantly through the mechanism of 

pinocytosis (introduction of fluids into a cell by invagination of the cell membrane, followed by 

formation of vesicles within the cells), not disruption of interendothelial junctions. 

Folate supplementation. Lee et al. conducted a series of studies to examine the effects of dietary 

folate supplementation on cerebral endothelial function and cerebral vascular damage induced by 

hyperhomocysteinemia in vivo. Before allocation to dietary intervention, all rats were fed a diet 

with added homocysteine (3.0 g per kg diet) for 2 weeks to induce hyperhomocysteinemia along 
42 

with the hyperhomocysteinemia-induced cerebrovascular endothelial dysfunction. The first study 

found that 2 weeks of dietary folate supplementation significantly ameliorated the 

hyperhomocysteinemia-induced cerebrovascular endothelial dysfunction, characterized by 

reduced endothelial nitric oxide synthase (eNOS) activity and glucose transporter protein 

(GLUT-1) activity. Specifically, the level of brain eNOS protein expression increased by 44 

percent (P=0.04) and the GLUT-1 level increased by 27 percent (P=0.04), in the comparison of 

rats fed an additional 8 mg per kg diet of folate to those on homocysteine diet. However, an 

unexpected result was observed for the cerebral content of the vascular cell adhesion molecule 

(VCAM-1). Rats fed an additional 8 mg per kg diet of folate had a 43 percent (P=0.04) decrease 

in VCAM-1 level. A subsequent study evaluated the effects of 8 weeks of dietary folate 

supplementation on cerebral vascular damage induced by hyperhomocysteinemia in vivo, in 

particular, investigating the structural features of the cerebral vasculature by electron 

microscopy. Consistent with the results from the first study, folate supplementation significantly 

increased the cerebral GLUT-1 protein, which had been decreased by a homocysteine diet. In the 

folate supplemented group, damaged vessels, annihilation of cell organelles, degeneration of 

mitochondrial bilayer, and perivascular detachment were also observed, although the damage of 

the cerebral vasculature was described as “more serious” in rats fed homocysteine-supplemented 

diet. In addition, dietary supplementation with folate for 8 weeks significantly reduced the 

percentage of damaged vessels.

Summary. Three studies examined BBB transport and permeability showed an abnormal 

selective transport of pyruvate across BBB in adult thiamine-deficient animals and intracellular 

edema associated with early deficiency results from a defect in cell membrane transport rather 

than a vascular leak of the inflammatory type across BBB. The leakage of BBB appears to be 

predominantly through the mechanism of pinocytosis, not disruption of interendothelial 

junctions. Two studies examined the effects of dietary folate supplementation on cerebral 

endothelial function and cerebral vascular damage induced by hyperhomocysteinemia in vivo. 

The results suggest that folate supplementation may ameliorate the hyperhomocysteinemiainduced cerebrovascular endothelial dysfunction and reduce cerebrovascular damage induced by 

hyperhomocysteinemia. 
43 

Table 6. Effects of B vitamins on blood brain barrier or cerebrovascular endothelial function 

Study, 

Year

Model 

Age/Weight 

Duration 

Intervention 

(vitamin B 

dose) 

N 

Control 

(Vitamin 

B dose) 

N BBB or cerebrovascular endothelial 

function outcomes 

Results

P 

Quality 

Thiamine deficiency in normal animals 

Warnock, 

1968 Rats 

Male 

S-D, 50-

65 g 

nda

“Thiamine 

deficient 

diet” 

15 

“Thiamine 

adequate 

diet” 

10 

Pyruvate-2-14C entered the brain 

directly in adult thiamine deficient 

animals 

+ nd B 

Early stage of TD: 

slight edema; marked 

spongy reticulation 

Refc

Robertson, 

1971 Rats 

Female 

Long 

Evans or 

Wistar 

Furth 

strains, 

Immature 

28-

46 

days 

Synthetic 

thiaminefree diet 

(0) 

46 

Interventi

on diet w/ 

thiamine 

HCl 40 

μg/100 g 

B.W. i.p. 

10 

Integrity of 

BBB with 

respect to 

absence of 

extravascular 

plasma 

proteins 

Late stage of TD: 

hemorrhages, tissue 

degradation and 

neuronal fallout 

+

<.001 B

Controls and early 

stage of TD (edema 

only) 

Ref Diffuse 

parenchymatous infiltration 

of the 

vestibular area 

Late stage of TD: 

hemorrhage and 

necrosis 

+ 

<.001 

Manz, 

1972 Rats 

Female 

Wistar 

Furth 

strains, 

Immature 

30-

45 

days 

Synthetic 

thiaminefree diet 

(0) 

37 

Interventi

on diet w/ 

thiamine 

HCl 40 

μg/100 g 

B.W. i.p. 

12 

Peroxidase was deposited in the contraluminal 

side basement membrane zone of intercellular 

gaps, but interendothelial junctional complexes 

were morphologically intact, in rat brains with 

late stage of TD

nd 

A

Folate Supplementation in deceased animals 

Cerebral expression level of GLUT-1 + .04 

Lee, 2004 Rats Cerebral expression level of VCAM-1 – .04 b Male SD, 8 wk 2 wk 8 mg/kg diet 

+ 0.3% Hcy 6 0.3% Hcy 6 

Endothelial nitric oxide synthase + .04 

A

Cerebral expression level of GLUT-1 + <.05 

Damaged cerebral capillary wall 

structure + nd Lee, 2005 Ratsb Male SD, 8 wk 8 wk 8 mg/kg diet 

+ 0.3% Hcy 4 0.3% Hcy 4 

% Damaged vessels in the 

hippocampus + <.05 

A

BBB = blood brain barrier; S-D=Sprague-Dawley; Hcy=homocysteine; GLUT-1=glucose transporter protein; 

VCAM-1= vascular cell adhesion molecule; i.p.= intraperitoneal; B.W.=body weight; TD=thiamine deficiency 

a At first signs of polyneuritis 

b Rats were fed a diet with 0.3% Hcy for 2 weeks before allocated to the intervention or control diets described in the 

table. All rats had induced hyperhomocysteinemia before the allocation. 

c Extravascular fluorescence was not seen in control animals (n=10) 

+ B vitamin deficient animals have abnormal function while normal B vitamin animals have normal function, or 

B vitamin supplemented animals have better function than normal B vitamin animals 

0 No difference between groups 

– B vitamin supplemented animals have worse function than normal B vitamin animals 
44 

Human Studies 

 The human studies addressing the evidence of the effect of B vitamins on age-related 

neurodegenerative conditions fall into three types, which will be discussed in the following 

order: intervention trials, studies of associations between B vitamin intake and neurocognitive 

function, and studies of association B vitamin tissue levels and neurocognitive function. 

 Among the 85 human studies reviewed, 30 were intervention trials, eight were B vitamin 

intake association studies, and 52 were B vitamin level association studies. Five studies reported 

data on both interventions and associations (at baseline). The large majority of studies were 

deemed to be of poor quality. Overall, three studies were of good quality, 25 of fair quality, and 

57 of poor quality. The most common reasons for grading study quality poor were lack of 

randomization or control in intervention studies, lack of adjustment for potential confounders in 

association studies, and poor or inadequate reporting of study design and results. Overall, 23 

studies had broad applicability, 40 had moderate applicability, and 23 had narrow applicability, 

often due to small sample size or focus on a specific population of diseased individuals. (One 

article contained two studies with different applicability ratings.) 

 Tables 7 and 8 provide an overall summary of the number of studies, number of subjects, 

quality, applicability, and summarized results of the evidence for B vitamin intervention (Table 

7) and B vitamin intake and levels associations (Table 8) with neurocognitive conditions. 

Table 7. Summary of intervention studies evaluating the effect of B vitamins on neurocognitive outcomes. 

INTERVENTION STUDIES

Change Severity Prevent/Delay Disease

Vitamin Studies 

N 

Quality Applicability Results Studies 

N 

Quality Applicability Results 

A 0 III 0 A 0 III 0 

B1 5 79 B 0 II 2 ↔ B 0 II 1 ↑

C 5 I 3 

1 32

C 1 I 0 

 

B2 0 

 

0 

 

A 0 III 0 

B6 2 151 B 1 II 1 ↔ 

C 1 I 1 

0 

 

A 1 III 0 A 0 III 0 

B12 12 492 B 2 II 5 ↔ B 0 II 0 ↔

C 10 I 8 

1 14

C 1 I 1 

A 0 III 0 

Folate 5 168 B 2 II 3 ↔ 

C 3 I 2 

0 

 

A 0 III 1 

Mix 6 462 B 2 II 4 ↔ 

C 4 I 1 

0 

 

Quality: A = good quality; B = fair quality; C = poor quality. 

Applicability: III = widely applicable; II = moderately applicable; I = narrowly applicable. 

Results: ↑ = treatment with, higher intake of, or higher level of associated with beneficial outcome (lessened severity, 

lower incidence) 

 ↔ = no association 

 ↓ = associated with worsened outcome (increased severity, higher incidence). 
45

Table 8. Summary of association studies evaluating the association of B vitamin intake or levels on neurocognitive outcomes. 

INTAKE STUDIES LEVELS STUDIE

Associated w/Severity Associated w/Prevalence or Incidence Associated w/Diagnosis A

Vitamin 

Studies N 

Quality 

Applicability 

Results 

Studies N 

Quality 

Applicability 

Results 

Studies N 

Quality 

Applicability 

Results 

Studies 

 A 0 III 0 A 0 III 0 A 0 III 2 

B1 3 727 B 2 II 3 ↔ 1 62 B 0 II 1 ↔ 7 394 B 1 II 2 ↔ 1 

 C 1 I 0 C 1 I 0 C 3 I 3  A 0 III 0 A 0 III 0 A 0 III 0 

B2 3 727 B 2 II 3 ↔ 1 62 B 0 II 1 ↔ 2 154 B 0 II 2 ↔ 

 C 1 I 0 C 1 I 0 C 2 I 0  A 0 III 0 A 1 III 2 A 0 III 2 

B6 4 539 B 3 II 3 ↔ 2 136,185 B 0 II 0 ↔ 8 1,587 B 2 II 3 ↔ 2 

 C 1 I 1 C 1 I 0 C 6 I 3  A 0 III 0 A 1 III 1 A 1 III 12 

B12 3 530 B 3 II 2 ↔ 2 136,120 B 0 II 1 ↔ 26 8,093 B 9 II 10 ↔ 7 

 C 1 I 1 C 1 I 0 C 16 I 4  A 0 III 0 A 1 III 2 A 1 III 10 

Folate 3 530 B 3 II 2 ↔ 3 136,248 B 0 II 1 ↔ 28 8445 B 11 II 17 ↑ 6 

 C 1 I 1 C 2 I 0 C 16 I 1 

Quality: A = good quality; B = fair quality; C = poor quality. Applicability: III = widely applicable; II = moderately applicable; I = narrowly applicable. Results: ↑ = treatment with, higher intake of, or higher level of associated with beneficial outcome (lessened severity, lower incidence)

↔ = no association ↓ = associated with worsened outcome (increased severity, higher incidence).
46 

Effect of B Vitamin Supplementation on Neurocognitive Function 

Thiamine (Vitamin B1) Intervention Studies 

Study Descriptions. Three randomized controlled trials (RCTs),61-63 one non-randomized 

comparative trial (N-RCT),62 and one uncontrolled cohort study64 reported data on thiamine 

supplementation among patients with probable or possible AD in four articles. All studies 

included subjects whose mean ages were greater than 70 years, and who met standard criteria for 

diagnosis of probable or possible dementia. Their average mini-mental status examination 

(MMSE) scores ranged from 14 to 18, indicating moderate to mild dementia. All RCTs tested 

three divided doses of 3 g per day thiamine, the N-RCT tested a maximum of 8 g per day 

thiamine and the single arm intervention trial tested a dose of 750 mg of a thiamine derivative. 

Thus, most studies used high-dose interventions compared to the US Recommended Daily 

Allowance (RDA) of 1.1 to 1.2 mg daily. The primary outcome for all studies was cognitive 

function (measured with MMSE or Alzheimer’s Disease Assessment Scale [ADAS]). In 

addition, two of the studies evaluated outcomes on behavior and/or emotion.61,64 All studies had 

small sample sizes (fewer than 25 subjects). All studies were assessed to poor quality (C). Two 

studies have moderate applicability and three narrow applicability. 

Overall Effect. Three of the five studies reported statistically significant effects in cognitive 

function after intervention with thiamine for short durations (1 to 3 months).61,62,64 Meador 1993 

reported statistically significant improvement of cognitive score (ADAS) in the initial months 

with reduced deterioration at 11 to 13 months, suggesting some beneficial effect of high dose of 

thiamine in decreasing the rate of progression of AD. This study also reported clinically 

significant effect of thiamine supplementation in the majority of subjects at dosages above 4 g 

per day. 

 Among these, Blass 1988 was a randomized crossover trial. The study did not document a 

wash out phase and compared thiamine to the intervention of niacinamide 750 mg as an active 

placebo. The follow-up study to Blass 1988, by Nolan 1991, was an RCT with parallel design 

that compared thiamine treatment to lactose placebo. It found no significant effects on cognitive 

function after treating to the same dose of thiamine for one year. 

 Meador 1993 reported two different experiments, and tested higher doses of thiamine 

(greater than 3 g per day). The first was a crossover RCT that compared thiamine to placebo 

without a washout phase between treatments. The second was a non-randomized comparative 

trial, which gave AD subjects sequentially higher doses of thiamine followed by placebo, and 

reported statistically significant improvements in the cognitive score (ADAS) at 3 dosages of 4 g 

per day or more thiamine. Of note this thiamine supplementation study reported improvement in 

the scores of Clinical Global Impression of Change (CGIC), which is a physician rated 

assessment of overall change from the baseline. However the study reported results among fewer 

than 10 subjects for dosages of 7 g or more between 8 to 13 months. 

 Mimori 1996 was an uncontrolled cohort study that used fursultiamine, a thiamine derivative 

that is easily converted into an active form of thiamine in the body. They evaluated nine people 

with AD and normal mean levels of blood thiamine. The study reported a statistically significant 

improvement in cognitive function (MMSE) and the emotional component of the GottfriesBrane-Steen (GBS) score after the intervention with fursultiamine. Blood thiamine levels 

increased markedly after fursultiamine intervention. 
47 

Interactions and Covariates. In its second experiment, Meador 1993 tested a maximum dose of 

thiamine for 13 months. The first phase of the study the thiamine dose was incrementally 

increased each month to a maximum of 6 g per day. In the second phase a “best dose” (defined 

as achievement of best ADAS scores) was used, and in the third phase a maximum dose of 8 g 

per day was achieved. However, after month 5, the results for the doses greater than 6 g of 

thiamine were reported only in a small subset of two to six subjects. High dose thiamine 

significantly reduced ADAS scores compared to baseline, but MMSE showed no significant 

change. No other interactions were reported in the studies. Only the uncontrolled cohort study 

reported blood levels of thiamine before intervention, and included subjects with normal blood 

levels. All the studies of thiamine intervention used tests of the same domain and measured 

global cognitive function as the outcome.

Summary. Five poor quality studies assessed in four articles reported data on the effect of 

thiamine intervention among people with probable or possible AD. Overall, two RCTs, and one 

cohort study reported improvement in cognitive function during short-term treatment of 

thiamine. However, without a comparable control group, it is difficult to assess the validity of the 

uncontrolled cohort study given the variable course of dementia over time. Two long-term 

studies failed to show any discernable differences in cognitive function as measured by MMSE. 

However the N-RCT that supplemented AD subjects with progressively higher doses of thiamine 

followed by placebo reported statistically significant improvement of cognitive score (ADAS) in 

the initial months with reduced deterioration at 11 to 13 months, suggesting some beneficial 

effect of high dose of thiamine intervention. This study also reported long-term clinical benefit 

from thiamine intervention. 
48 

Table 9. Effect of thiamine (vitamin B1) intervention on cognitive function tests 

Design Change Net Change 

Author 

Year 

Duration 

Intervention 

Dose g/day 

Control 

Route N Test /Subtest 

Maximum Score 

Base value 

Value 

P value

Change 

Value 

P value

Net Change 

Population 

Mean Age (yr) 

Applicability 

Quality 

RCT a 

3 14.2 +1.3 .08 +0.7 <.00

1 Blass 

1988 3 mo 

Niacinamide 750 mg 

po 

1

1 MMSE  30

14.2 +0.5 NS

A

D 72d C

3 18 0 NS +1 nd 

Placebo po 

1

7 MMSE  30 18 -1 nd 

3 69%↓ b NS -10%↓ b NS 

Meador 

1993 

Study 1 

1 mo 

Placebo 

po 

1

7 MMSE  30

79%↓ b <.03 

A

D 71ddC

Nolan 3 5 16.6 -6.2 <.05 -4.8 nd 

1991 

12 

mo Placebo po 5 MMSE  30 16.0 -1.4 <.05

A

D 76d C

3 36 +2.1 nd -3 nd 

Placebo po 

1

7 ADAS  120 36 +6.7 

3 56%↓ c NS -19%↓ c <.02 

Meador 

1993 

Study 1 

1 mo 

Placebo 

po 

1

7 ADAS  120

75%↓ c <.04 

A

D 71ddC

3 7.4 +0.1 NS +0.6 NS 

Niacinamide 750 mg po 

1

1 Blessed  nd 7.4 -0.5 NS 

3 11.1 +2.3 NS +1.2 NS 

Blass 

1988 3 mo 

Niacinamide 750 mg po 

1

1 Haycox  nd 11.1 +1.2 NS 

A

D 72d C

N-RCT 

4 1

7 21.2 +0.5 NS +0.1 nd 

Placebo 

po 1

5 

MMSE  30

21.5 +0.4 NS 

5 1

7 21.2 +0.6 NS +0.2 nd 

Placebo 

po 1

5 

MMSE  30

21.5 +0.4 NS 

6 1

7 21.2 +0.5 NS +0.1 nd 

Meador 

1993 

Study 2 

1 mo d

Placebo 

po 1

5 

MMSE  30

21.5 +0.4 NS 

A

D 71ddC

4 1

6 27.2 -3.8 ≤.01 -1.7 nd 

Placebo 

po 1

3 

ADAS  120

26.2 -2.1 NS 

5 1

6 27.2 -3.8 ≤.05 -1.7 nd 

Placebo 

po 1

3 

ADAS  120

26.2 -2.1 NS 

6 1

6 26.6 -2.3 NS -0.2 nd 

Meador 

1993 

Study 2 

1 mo d

Placebo 

po 1

3 

ADAS  120

26.2 -2.1 NS 

A

D 71ddC

Cohort 

MMSE  30.

0 17.2 +2.2 <.05 

Hasegawa Dementia 

Scale 

32.

5 17.0 +0.6 NS 

Mimori 

1996 3 mo Fursultiamine 

100 mg e po 9 

GBS  228 59.8 -7.4 <.10 

A

D 72d C
49 

 Higher score indicates better cognitive function.  Lower score indicates better cognitive function. MMSE, minimental status examination; ADAS, Alzheimer disease assessment scale; Blessed, behavioral rating according to 

Blessed et al.; GBS, Gottfries-Brane-Steen scale; Haycox, behavioral scale of Haycox; mo, month; po, orally.

a

 Blass 1988, and Meador 1993 are crossover trials. 

b

 Proportion (or calculated net proportion) of patients with lower MMSE score (deterioration). c

 Proportion of patients with ADAS higher score (deterioration). 

d

 The different doses of thiamine were supplemented sequentially, for one month each, followed by placebo. e

 Fursultiamine (thiamine tetrahydrofurfuryl disulfide hydrochloride) a derivative of thiamine. 

Riboflavin (Vitamin B2) Intervention Studies 

No prospective trial has evaluated the effect of vitamin B2 treatment on neurocognitive function.

Vitamin B6 Intervention Studies 

Study Descriptions. Two RCTs assessed the effect of B6 intervention on cognitive function in 

humans.65,66 They included 75 and 38 cognitively intact subjects in the intervention arm 

respectively. One RCT used 75 mg of B6 per day for 5 weeks while the other trial administered 

20 mg of B6 per day for 12 weeks. Both doses are considerably higher than the US RDA dose of 

1.3 to 1.7 mg daily. One study used digit symbol coding, vocabulary test, and digit spanbackwards from WAIS III as well as the Stroop test for executive function and initial letter for 

verbal fluency. The second RCT applied the Associate Recognition Task and the Long Term 

Memory Storage to assess cognitive function. The trials were of moderate (B) and low (C) 

quality and had narrow and moderate applicability, respectively. 

Overall Effect. Deijen 1992 reported a significant decrease in Long Term Memory Storage for 

the intervention group, which corresponds to memory improvement (P<0.03). However, no 

significant effect was recorded in the Associate Recognition Task for the intervention group in 

the same study. However, no formal comparison between intervention and placebo group was 

provided in the article and no information is given for the significance of the changes in the 

placebo group. 

Interactions and Covariates. There is no adequate evidence to support any dose effect of B6 on 

the outcomes. There was no evidence across studies of differences in effect on tests of different 

cognitive domains. No other interactions were reported in the studies. 

Summary. Two RCTs of moderate and low quality, with narrow and moderate applicability for 

cognitively intact populations investigated the effect of B6 intervention on cognitive function in 

humans. With treatment, a significant improvement was found with one cognitive function test. 

It is uncertain whether this change is of any clinical benefit. It is also unclear whether the 

changes with treatment were significantly different than changes in the control arm in the same 

study. No other significant effect was reported in the studies. Because of the very limited 

evidence no conclusions can be drawn for the effect of B6 on preventing cognitive function 

decline. 
50 

Table 10. Effect of vitamin B6 intervention on cognitive function tests 

Design Change Net Change 

Author 

Year 

Duration Intervention 

Dose 

mg/day 

Control 

Route 

N Test /Subtest 

Maximum Score 

Base value 

Value 

P valu

e

Chan

ge 

Value 

P value

Net Change 

Population 

Mean Age (yr) 

Applicability 

Quality 

RCT 

75 po 63.4 +7.3 NS +2.5 NS 

Placebo 

75 Digit-Symbol Coding 

(WAIS III) 

nd

62.3 +4.8 NS

75 po 22.1 +0.6 NS +0.8 NS 

Placebo 75 

Verbal Ability: 

Vocabulary  (WAIS 

III) 

nd 21.9 -0.2 NS

75 po 6.1 0 NS -0.4 NS 

Placebo 75 Digit Span-Backwards

 (WAIS III) nd 7.1 +0.4 NS

75 po 2.34 -0.06 NS +0.06 NS 

Placebo 75 Stroop  nd 2.51 -0.12 NS

75 po 29.3 +1.2 NS -2.1 NS 

Bryan, 

2002 

5 

wk 

Placebo 75 Verbal Fluency: Initial 

letter  nd 23.7 +3.3 NS

Normal 74 d B 

20 38 9 3.2 b +0.1 NS +1.2 nd 

Placebo 38 

Associate Recognition 

Task a  3.9 b -1.1 nd

20 38 9 0.35 -0.35 <.03 -0.8 nd 

Deijen, 

1992

12 

wk 

Placebo 

po 

38 

Long Term Memory 

Storage c  0.45 +0.45 nd

Normal 83 dd C 

 Higher score indicates better cognitive function.  Lower score indicates better cognitive function. WAIS, Wechsler 

Stroop, Stroop Color-word Test; po, orally

a

 Test of long term verbal memory, same as Associate Learning Task with 1 hour delay. b

 Results reported graphically. 

c

 Difference (by subtraction) between Associate Learning and Recognition Tasks (what is forgotten), also known as 

Forget Score.

Cobalamin (Vitamin B12) Intervention Studies 

Study Descriptions. Five RCTs, one N-RCT, and seven uncontrolled cohort studies assessed the 

effect of B12 intervention on cognitive function in humans.65,67-78 Among the RCTs (Table 11) 

sample size ranged from 18 to 70 in the intervention arms. Two RCTs recruited cognitively 

intact participants with normal B12 while another two recruited cognitively intact subjects with 

low B12 levels. Low B12 levels was defined as 136 to 203 pg/mL in one RCT and less than 163 

pg/mL in the other. The fifth RCT included subjects with cognitive impairment. The five RCTs 

used different doses and routes of B12 interventions ranging from 0.01 mg B12 per day orally to 

1 mg 3 times per week B12, intramuscularly. Two trials used oral B12, the remainder 

intramuscular. B12 doses were higher than the US RDA of 2.4 μg per day. Almost all trials 

implemented more than one cognitive function test. MMSE was used by three trials, several parts 

of the Wechsler Adult Intelligence Scale (WAIS) by two trials while a number of miscellaneous 

tests were also reported (Table 12)., including the Cognitive Subscale of Cambridge Examination 

for Mental Disorders of the Elderly (CAMCOG), 12 word learning test – immediate and delayed 

– Stroop, initial letter from verbal fluency, memory quotient, lower and upper limit of retention 

span, visual and verbal memory, verbal and performance Intelligence Quotient (IQ). RCTs were 

of moderate to low quality (1A, 2B, 2C) and had narrow to moderate applicability. 

 Among the N-RCT and the cohort studies (Table 12), sample size ranged between 14 and 56. 

Three studies recruited demented participants, regardless of specific diagnosis. Two selected 
51 

only participants with low serum B12 levels defined as less than 200 pg/mL in one trial and less 

that 300 pg/mL in the other trial. There were three additional trials that included subjects with 

low B12 levels (less than approximately 200 pg/mL); one recruited cognitively impaired 

individuals with B12 less than 203 pg/mL and the other included cognitively intact persons with 

B12 values equal or less than 203 pg/mL while the third one evaluated patients with AD or other 

dementias and B12 values less than 190 pg/mL. Two other studies included subjects with AD, 

regardless of B12 status. As with the RCTs, cobalamin doses were considerably higher than the 

RDA. Almost all trials implemented more than one cognitive function test (Table 12). MMSE 

was used by five trials, Mattis’ Dementia Rating Scale (DRS) by two studies, WAIS by one trial, 

GBS by two trials while a number of miscellaneous tests were also reported, including 

CAMCOG, Interview for Deterioration in Daily living activities in Dementia (IDDD) -Initiative, 

IDDD-Performance, Revised Memory and Behavioral Problems (RMBPC) -Memory, RMBPCDisruptive behavior, delayed verbal word learning test, verbal fluency, similarities, trail making 

test, Rivermead behavioral face recognition test, Hasegawa’s Dementia Rating Scale (HDS), and 

Consortium to Establish a Registry for Alzheimer's Disease (CERAD). The N-RCT was of low 

quality and had moderate applicability. Cohort studies were (by definition) of low quality (C) 

and had narrow to moderate applicability. 

Overall Effect. Only one RCT (Hvas 2004) found a significant difference in effect on 12 word 

learning test at 15 minutes between the B12 and the control groups among cognitively impaired 

subjects. With other tests, some significant changes were found either with or without B12 

supplementation, but these changes were not significantly different than each other. Kwok 1998, 

which included cognitively intact participants with low B12 (<163 pg/mL) revealed a significant 

improvement for B12 group in performance IQ; however, this was not significantly higher than 

the change in the control group. No other significant effects were reported in the RCTs. 

 Among the seven uncontrolled cohort studies, Teunisse 1996 reported that MMSE score was 

significantly worse after treatment among demented individuals with low B12 levels (<200 

pg/mL). Ikeda 1992 found a significant improvement in Mattis’ DMR scale at 2 months among 

people with AD, which however, was not maintained 4 months after the end of treatment. In the 

same study, GBS and HDS were also significantly improved at the end of treatment, but their 

improvement was also not maintained 4 months later. Van Asselt 2001, in the N-RCT, found that 

after treatment, performance on the delayed recall of verbal word learning test, similarities and 

verbal fluency test was significantly improved among cognitively intact subjects with low B12 

(<203 pg/mL). In contrast, Teunisse 1996 noted significant deterioration in several tests 

including IDDD-Initiative, IDDD-Performance, and RMBPC-Disruptive behavior. The other 

five cohort trials found no change in cognitive function after B12 treatment. 

Interactions and Covariates. RCTs reached statistical significance less often than cohort studies. 

When they reported significant changes, RCTs usually implied an improvement of cognitive 

function. Significant changes for cohort studies were not consistent, some finding improvement, 

some decline of cognitive function scores. There is large heterogeneity among RCTs and cohort 

studies in terms of dose, route, and duration of treatment and it would be difficult to support any 

conclusion about a potential dose effect. However, the only significant changes in cognitive 

score were found when B12 was injected rather than given orally. Seal 2002 directly evaluated 

the effect of B12 oral supplementation in two intervention arms, one receiving double the dose of 

the other, and compared these groups with placebo. No significant change was found when 
52 

MMSE score differences of the three groups were compared. In the cohort study by Mitsuyama 

1988 five of the 14 demented participants were orally supplemented with 2 mg B12 daily while 

nine subjects had an additional B12 injection of 0.5 mg. Only those receiving B12 injections 

showed an improvement from baseline in GBS (P value not reported). 

 Ito 2001 analyzed the results based on the severity of dementia of Alzheimer’s type. Both 

subjects with questionable or mild AD and participants with moderate or severe AD had nonsignificant improvement in MMSE after treatment. Abyad 2002 analyzed the results according to 

treatment duration for dementia before the trial. Both subjects with short-term treatment and 

subjects with long-term treatment improved MMSE; short-term treatment participants had a 

significant increase. Martin 1992 evaluated separately patients with cognitive impairment of long 

duration and patients with cognitive impairment of short duration. Only the subjects with disease 

of short duration showed a significant improvement in Mattis’ DRS. 

 There was no evidence across studies of differences in effect on tests of different cognitive 

domains. 

Summary. Five RCTs of narrow to moderate quality, one non-randomized comparative study, 

and seven cohort studies assessed the effect of vitamin B12 intervention on cognitive function in 

humans. All studies had narrow to moderate applicability. They evaluated populations that 

included normal participants, subjects with cognitive impairment, dementia, or AD. Several 

studies recruited only individuals with low B12 levels, however the definition for low B12 levels 

varied. There was large heterogeneity among studies in terms of dose and route of intervention as 

well as the cognitive function assessment instrument. Although several of the studies showed 

small changes in cognitive function, few reached statistical significance. Across studies that 

assessed similar populations after implementing the same test, results were conflicting. Several 

cohort studies revealed significant improvement while a smaller number of cohorts reported a 

significant decline in scores for cognitive function. However, the interpretation of these studies is 

difficult because they analyzed subjects who may have had variable courses of dementia over 

time, without using a control group for comparison. Vitamin B12 was given intramuscularly in 

the only RCT that found a significant effect in the treatment group compared to controls. 

Similarly, only cohort studies that used intravenous or intramuscular vitamin B12 reported a 

significant effect on cognitive function scores. However, given the lack of data directly 

comparing oral and injected routes of vitamin B12 and the paucity of controlled trials limits any 

conclusions regarding the utility of different routes of administration. There was very limited 

evidence whether other covariates may interact with B12 supplementation. Most studies did not 

take into consideration potential factors such as disease duration that may interfere with B12 

effect.
53 

Table 11. Effect of vitamin B12 intervention on cognitive function tests in randomized controlled trials. 

Change Net 

Change 

Autho

r 

Year 

Duration 

Intervention 

Dose mg/da

y 

Control 

Route N Test /Subtest

Maximum Score 

Base value 

Value 

P value

Change 

Value 

P value

Net Change 

Population 

Mean Age (yr) 

Applicability 

Quality 

1/wk b Hvas, IM 70 26 +0.3 NS +0.1 NS 75 

2004 4 wk a

Placebo 70 MMSE  30 27 +0.2 NS 

Cognitive 

impairment 74 ddA

0.01 10 15.4 0 -1.6 82 

0.05 po 10 19.7 +1.0 -0.6 nd 85 Seal, 

2002 ~4 wk 

Placebo 11 

MMSE  30 

19.6 +1.6 

NS c Normal with 

low serum 

B12 d 78 

d B

1/mo e IM 27 22.2 +0.1 NS -0.1 NS Kwok, 

1998 

3-6 m

o Control 23 MMSE  30 23.8 +0.2 NS 

Normal with 

low 

serum B12 f

77 ddC

0.015 po 62.5 +6.9 NS +2.1 NS 

Placebo 75 

Digit-Symbol 

Coding 

(WAIS III) 

nd 62.3 +4.8 NS 

0.015 po 23.3 -0.3 NS +0.2 NS 

Placebo 75 Vocabulary 

(WAIS III) 

nd 21.9 -0.5 NS 

0.015 po 6.7 +0.2 NS -0.2 NS 

Bryan, 

2002 5 wk 

Placebo 75 

Digit SpanBackwards 

(WAIS) 

nd 7.1 +0.4 NS 

Normal 74 d B

1/mo e IM 27 10.4 +0.3 NS +1.3 NS Kwok, 

1998 

3-6 m

o Control 23 

Digit Span 

(WAIS) 

nd 11.6 -1.0 NS 

Normal with 

low 

serum B12 f

77 ddC

1/wk b IM 70 89 +1.3 .04 -0.6 NS 75 

Placebo 70 CAMCOG  100 89 +1.9 .001 74 

1/wk b IM 70 5 +0.2 NS -0.2 NS 75 

Placebo 70 

12 word 

learning test, 

immediate 

12 5 +0.4 .04 74 

1/wk b IM 70 2 +0.2 NS -0.5 0.04 75 

Hvas, 

2004 4 wk a

Placebo 70 

12 word 

learning test, 

15 min 

12 2 +0.7 .001

Cognitive 

impairment 

74 

ddA

0.015 po 2.50 -0.03 NS +0.0

9 NS 

Placebo 

75 Stroop  nd 

2.51 -0.12 NS 

0.015 po 29.3 -0.1 NS -3.4 NS 

Bryan, 

2002 5 wk 

Placebo 75 

Verbal 

Fluency: 

Initial letter 

nd 23.7 +3.3 NS 

Normal 74 d B

0.1x5 /wk g IM 18 90 -3 NS -7 NS 

Control 22 

Memory 

Quotient  100 88 +4 ND

0.1x5 /wk g IM 18 38 -12 NS -8 NS 

Control 22 

Lower limit of 

retention  nd 45 -4 NS 

0.1x5 /wk g IM 18 48 -6 NS -1 NS 

Kral, 

1970 

3-6 

mo 

Control 22 

Upper limit of 

retention  nd 45 -5 NS 

Normal nd d C

1/mo e IM 27 12.7 -3.0 NS +0.7 NS 

Control 23 

Visual 

Memory  nd 15.3 -3.7 NS 

1/mo e IM 27 7.8 -1.1 NS +1.0 NS 

Control 23 

Verbal 

Memory  nd 11.4 -2.1 NS 

1/mo e IM 27 58.2 +1.1 NS +2.3 NS 

Control 23 Verbal IQ  nd 60.1 -1.2 NS 

1/mo e IM 27 74.9 +5.8 <.00

5 +7.3 NS 

Kwok, 

1998 

3-6 m

o 

Control 23 

Performance 

IQ  nd 

84.3 -1.5 NS 

Normal with 

low serum 

B12 f 77 ddC
54 

 Higher score indicates better cognitive function.  Lower score indicates better cognitive function. MMSE, minimental status examination; WAIS, Wechsler Adult Intelligence Scale CAMCOG, Cambridge Subscale of CAMDEX, 

assesses orientation, language, memory, praxis, attention, abstract thinking, perception and calculation (includes 

MMSE); Stroop, Stroop Color-word Test; po, orally; IM, intramuscular; IV, intravenous 

a

 4 wk of treatment were followed by 3 mo follow-up without treatment; results are reported at baseline and at the end 

of 3 mo follow-up. 

b

 1 mg weekly for 4 weeks. 

c

 ANOVA, comparing all 3 groups simultaneously. 

d

 136-203 pg/mL. 

e

 1 mg 3x in week 1, then 1/week x 3 weeks, then 1/month. f

 <163 pg/mL. 

g

 100 μg x 5 times /wk x 14 wk. 

Table 12. Effect of vitamin B12 intervention on cognitive function tests in non-randomized trials 

Intervention Change 

Author 

Year 

Duration 

Dose 

mg/day 

Route 

N Test 

/Subtest 

Maximum Score 

Base value 

Value 

P value

 Change 

Population 

Mean Age (yr) 

Applicability 

Quality 

Non-randomized comparative trial 

1 IM 16 MMSE  nd No change 

1/wk a IM 16 

Forward & 

Backward 

Digit Span 

(WAIS-R) 

nd No change 

+5 

1/wk a IM 16 

Verbal Word 

Learning 

Test 

(Delayed 

recall) 

nd 6 

+1 

0.03

-2 0.03 1/wk a IM 16 

Verbal 

Fluency  nd 20 -5 

0 1/wk a IM 16 

Similarities

 nd 7 -2 0.04

1/wk a IM 16 Trail Making 

Test  nd No change 

van Asselt, 

2001 5 mo 

1/wk a IM 16 

Rivermead 

Behavioral 

Face 

Recognition 

Test 

nd No change 

Normal 

Low serum B12 b 71 dd C 

Cohort studies 

1.5 – 3 c nd 14 MMSE  30 10.1 +0.3 NS AD d 78 

1.5 – 3 c nd 6 MMSE  30 17.3 +0.4 NS Questionable or mild 

AD d 78 Ito, 2001 4 wk 

1.5 – 3 c nd 8 MMSE  30 4.8 +0.1 NS Moderate or severe 

AD d 78 

dd C 

Teunisse, 

1996 6 mo 1 e IM 19 MMSE  30 17.5 -1.8 <0.05 Dementia 

Low serum B12 f 76 dd C 

Continued 
55 

Table 12. Effect of vitamin B12 intervention on cognitive function tests in non-randomized trials (Continued) 

Intervention Change 

Author 

Year 

Duration 

Dose 

mg/day 

Route 

N Test 

/Subtest 

Maximum Score 

Base value 

Value 

P value

 Change 

Population 

Mean Age (yr) 

Applicability 

Quality 

1/mo g IV 56 MMSE  30 14.5 +0.5 nd Dementia 

Low serum B12 h 82 

1/mo g IV 22 MMSE  30 19 +6 .007

Dementia 

(Short-term Tx) 

Low serum B12 h

Abyad, 82 

2002 12 mo 

1/mo g IV 34 MMSE  30 18 +4 NS 

Dementia 

(Long-term Tx) 

Low serum B12 h 82 

d C 

1.5/wk k IV 19 MMSE  30 20 L +1 NS 

Ikeda, 1992 8 wk j

1.5/wk k IV 19 

Mattis’ 

DRS  150 112 L +3 <.05

AD 71 d C 

1/mo m IM 13 

Mattis’ 

DRS  144 108 -3 NS 

Cognitive impairment 

(long duration) 

Low serum B12 n Martin, 

1992 >7 mo 

1/mo m IM 5 

Mattis’ 

DRS  144 108 +20 .008

Cognitive impairment 

(short duration) 

Low serum B12 n

79 d C 

2 + 0.5 po + 

IM 9 GBS  nd Improvement 

from baseline o Mitsuyama, 

1988 2 mo 

2 po 5 GBS  nd No change from 

baseline o

Dementia 53 dd C 

Ikeda, 1992 8 wk j

 1.5/wk k IV 19 GBS  nd 90 -10 L <0.05 AD 71 d C 

1 e IM 19 CAMCOG  106 64.9 -1.4 NS 

1 e IM 19 

IDDDInitiative  36 13.8 -4.9 <0.05

1 e IM 19 

IDDDPerformanc

e 

44 12.7 -7.8 <0.05

1 e IM 19 

RMBPCMemory  28 17.5 -0.4 NS 

Teunisse, 

1996 6 mo 

1 e IM 19 

RMBPCDisruptive 

behavior 

32 4.4 -2.6 <0.05

Dementia 

Low serum B12 f 76 dd C 

Ikeda, 1992 8 wk j

 1.5/wk k IV 19 HDS  nd 28 +5 L <0.05 AD 71 d C 

Carmel, 

1995 6-8 mo 1/wk p IM 14 CERAD  nd

Improvement: 1 

subject q

No change: 12 

subjects q

Worse: 1 

subject q

AD, Dementia 

Low serum B12 r 71 d C 

 Higher score indicates better cognitive function.  Lower score indicates better cognitive function. CAMCOG, 

Cambridge Subscale of CAMDEX, assesses orientation, language, memory, praxis, attention, abstract thinking, 

perception and calculation (includes MMSE); MMSE, mini-mental status examination; IDDD, Interview for 

Deterioration in Daily living activities in Dementia, caregiver assessment of functioning in the past week; subscales 

for initiative and performance; RMBPC, Revised Memory and Behavioral Problems; 3 subscales for memory, 

depression (not included here), and disruptive behavior; CERAD battery includes MMSE, 15-item naming task, verbal 

fluency task, verbal memory task, visuoconstructive task; GBS, Gottfries-Brane-Steen scale; HDS, Hasegawa’s 

Dementia Rating Scale; WAIS-R, Wechsler Adult Intelligence Scale - Revised; Mattis’ DRS, Mattis’ Dementia Rating 

Scale. 
56 

a

 1 mg weekly x 4 weeks, then monthly x 4 months. 

b ≤ 203 mg/mL. c

 1.5 mg/day x 2 weeks, then 3.0 mg/day x 2 weeks. 

d

 Dementia of Alzheimer’s Type (DAT); Clinical Dementia Rating (questionable dementia 0.5 points, mild 1, 

moderate 2, severe 3). 

e

 1 mg/day x 5 days, then per month, or 1mg/week x 5 weeks, then bi-monthly. f

 <200 pg/mL. 

g

 1 mg IV daily for 1 week; then weekly for 1 month; then monthly thereafter. h

 <300 pg/mL. 

j

 There is also follow-up for 4 months after treatment completion: NS results compared to baseline were reported at 

the end of that period. 

k

 500 μg 3x/week x 8 weeks. 

L

 Results are presented graphically. 

m 1 mg/day for 1 week, weekly for 1 month, then monthly ≥6 months. n

 <203 pg/mL. 

o

 Results not reported. 

p

 1 mg weekly for 8 weeks, then monthly for ≥4 months. q

 Results on CERAD scores are not reported. 

r

 <190 pg/mL. 

Folate Intervention Studies 

Study Descriptions. Three RCTs65,79,80 and two uncontrolled cohort studies81,82 reported data on 

folate supplementation and the effect on cognitive function or therapeutic benefit. Two studies 

were conducted among subjects with dementia, one among cognitive impaired, one among 

normal subjects, and the fifth among those with PD. All but one study included subjects whose 

mean ages were 60 years and above; the remaining study did not document mean age. The 

studies tested various doses of folic acid or folate ranging from 0.75 to 20 mg daily. These doses 

are all substantially larger than the US RDA of 0.4 to 1 mg per day. Study durations ranged from 

5 to 17 weeks. The primary outcome for three studies was cognitive function measured with 

WAIS-R and/or other cognitive tests. One study also evaluated therapeutic benefit. About 130 

subjects were tested in five studies. All studies were of moderate to poor quality (2 B, 3 C). 

Three studies have moderate, and two narrow applicability. 

Overall Effect. Among the five studies that measured cognitive function in people with 

dementia, cognitive impairment, or no disease, one RCT found a trend towards worsening of 

neuropsychological scores in the folic acid treatment group, suggesting a negative benefit of high 

dose folate among subjects with dementia. Two other studies, one RCT and one uncontrolled 

cohort studies found statistically significant improvement with folic acid or folate treatment 

compared with placebo among demented, cognitive impaired, and normal subjects, but did not 

report any clinical benefit. The study of patients with PD found no therapeutic benefit. 

 Fioravanti 1997 compared the effects of folic acid intervention with placebo among 

cognitively impaired subjects who had serum folate levels below 3 ng/mL. Cognitive function 

was assessed using six components of the Randt Memory Test (RMT). Compared to baseline the 

folic acid treatment group showed significant improvement in Attention Efficiency score, one of 

the six components of RMT, after 60 days treatment. However comparison between folic acid 

and placebo groups showed significant changes in the actively treated group with improvement 

in four out of six cognitive components of RMT. 

 Bryan 2002 was a double blind, placebo controlled randomized trial conducted to assess the 

effect of vitamin supplementation and dietary intake among normal women. The study utilized a 

mixed factorial design with four treatment groups (B6, B12, folate, and placebo) and three age 
57 

groups (younger, middle-aged, and older) to assess the effect on cognitive performance. Here we 

summarize the results from the subgroup of older women who were treated with a small dose of 

folate (0.75 mg). In post hoc comparisons of two measures of memory, Rey Auditory-Verbal 

Learning Test (RAVLT) immediate recall and recognition list, and verbal ability (verbal fluencyinitial letter), older women in the folate treatment group identified significantly more words 

when compared to the placebo group. No significant effect was observed in other tests. 

 Sommer 2003, in a very small double blind RCT, compared 20 mg per day of folic acid to 

placebo in seven subjects who fulfilled the standard diagnostic criteria for dementia. There were 

small trends towards a negative effect on cognitive abilities with folic acid treatment in two of 

the cognitive tests, the Associated Learning subtest that measures verbal learning, and Trails B 

that measures perpetual motor speed. 

 Rapin 1988 recruited subjects with dementia and low red blood cell (RBC) folate levels. This 

study was an uncontrolled cohort study that treated dementia subjects with 50 mg per week of 

folinic acid for about 17 weeks. Treated subjects had a significantly improved performance in 

five of 16 cognitive tests. They also reported improved feeling of well-being. 

 The single study of patients with PD, by McGeer 1972, was a cohort study of 15 mg per day 

of folic acid among 18 subjects. The study found that the folic acid intervention provided slight 

to no therapeutic benefit assessed by subjective or objective change in PD symptoms. 

Interactions and Covariates. The intervention trials did not provide adequate evidence to 

support any dose effect of folate on the outcomes. However, Fioravanti 1997 found that the 

cognitive improvement after folate intervention was correlated in a linear fashion with the low 

levels of folate at baseline. One RCT80 and one uncontrolled study82 studied the effect of folic 

acid intervention on cognitive function among subjects with low serum or RBC folate levels, and 

one RCT among those with normal folate levels.79. Two other studies did not provide data on 

blood folate levels before or after intervention. One RCT and one uncontrolled cohort study 

reported significant effects in the same cognitive domain. 

Summary. A total of five studies of moderate to poor quality reported data on the effect of folate 

intervention among normal people or those with dementia, cognitive impairment, or PD. Overall, 

one RCT among subjects with dementia and normal folate levels found a trend towards worse 

performance in the cognitive function scores with folic acid intervention. Two studies, one RCT 

and one uncontrolled cohort study found statistically significant improvements in the cognitive 

scores in the actively treated groups among demented, cognitive impaired, and normal subjects 

and the last found no benefit among PD subjects. However, interpretation of the cohort studies is 

difficult without a comparable control group given the variable course of dementia over time. 

None of the studies provided data on clinically significant effect after the vitamin intervention. 
58 

Table 13. Effect of folic acid or folate intervention on cognitive function tests 

Design Change Net 

Change 

Author 

Year 

Duration Intervention 

Dose 

mg/day 

Control 

Route N Test /Subtest 

Maximum Score 

Base value 

Value 

P value

Change 

Value 

P value 

Net Change 

Population 

Mean Age (yr) 

Applicability 

Quality 

RCT 

WAIS-R 

0.75 7

5 nd 62.5 +6.9 nd +2.1 NS 

Placebo 

po n

d 

Digit Symbol Coding (120 s) 

 62.3 +4.8 

0.75 7

5 nd 6.7 +1.7 nd +1.3 NS 

Bryan 

2002 

5 

wk 

Placebo 

po n

d 

Digit span - Backwards 

 7.1 +0.4 

Normal 74d B

20 4 nd 4.9 0 nd -1.7 NS 

Placebo po 3 

Wechsler Memory Scale  -

Logical Memory Subtest 4.6 +1.7 

20 4 nd 16.6 -7.8 nd -7.5 .08 

Placebo po 3 

Wechsler Memory 

Scale  - Associate Learning 

Subtest 11.0 +0.3 

20 4 nd 107.

8 -2.5 nd +10.

0 NS 

Sommer 

2003 

10 

wk 

Placebo 

po 

3 

Pro-rated Verbal IQ 

(WAIS-R)  110.

0 

+12.

5 

Dementia

Normal 

folate 

77d C

Miscellaneous 

15 1

6 nd 55.3 +4.2 nd +5.5 <0.00

7 

Placebo 

po 1

4 

Acquisition & recall a  

 62.1 -1.2 

15 1

6 nd 56.1 +7.4 nd +7.4 <0.00

7 

Placebo 

po 1

4 

Delayed recall a  

 63.0 0 

15 1

6 nd 49.3 +6.8 nd +6.3 <0.00

2 

Placebo 

po 1

4 

Memory index a  

 57.1 0.5 

15 1

6 nd 4.3 +0.5 nd +0.7 <0.00

5 

Placebo 

po 1

4 

Encoding a 

 5.3 -0.2 

15 1

6 nd 3.28 +0.6

3 nd +0.5

7 NS 

Placebo 

po 1

4 

Cognitive efficiency a  

 4.25 +0.0

6 

15 1

6 nd 6.40 +1.12 

<0.0

5

+0.9

7 NS 

Fioravanti 

1997 

60 

d 

Placebo 

po 1

4 

Attention efficiency a  

 6.83 +0.0

7 NS

Cognitive 

impaired 

Low 

folate b

80ddB

0.75 7

5 nd 2.50 -0.03 nd +0.0

9 NS 

Placebo 

po n

d 

Executive function Stroop 

 2.51 -0.12 

Bryan 

2002 

5 

wk 

0.75 po 7

5 Verbal fluency: Initial letter  nd 29.3 -0.1 nd -3.4 NS 

Normal 74d B
59 

Design Change Net 

Change 

Author 

Year 

Duration Intervention 

Dose 

mg/day 

Control 

Route N Test /Subtest 

Maximum Score 

Base value 

Value 

P value

Change 

Value 

P value 

Net Change 

Population 

Mean Age (yr) 

Applicability 

Quality 

Placebo n

d 23.7 +3.3 

0.75 po 7

5 nd 23.3 -0.3 nd -0.1 NS 

Placebo n

d 

Verbal ability - Vocabulary 

 21.9 -0.1 

20 po 4 nd 40.8 +1.2 nd -0.2 NS 

Placebo 3 

Boston Naming 

Test  42.3 +1.4 

20 po 4 nd 29.5 +3.3 nd +8.3 NS 

Placebo 3 

Controlled Oral Word 

Association Test  36.0 -5.0 

20 po 4 nd 233.

0 

+14.

8 nd +31.

5 NS 

Placebo 3 

Speed/Concentration: 

Trails A  277.

7 -16.7 

20 po 4 nd 373.

0 

+20.

3 nd +75.

0 .08 

Placebo 3 

Speed/Concentration: 

Trails B  412.

0 -54.7 

20 po 4 nd 38.4 -1.5 nd +6.9 NS 

Sommer 

2003 

10 

wk 

Placebo 3 

Speed/Concentration: 

Finger Tapping Test  32.7 -8.4 

Dementia

Normal 

folate 

77d C

Continued 
60 

Table 13. Effect of folic acid or folate intervention on cognitive function tests (Continued) 

Design Change Net Change 

Author 

Year 

Duration Intervention 

Dose 

mg/day 

Control 

Route N Test 

/Subtest 

Maximum Score 

Base value 

Value 

P value

Change 

Value 

P value 

Net Change 

Population 

Mean Age (yr) 

Applicability 

Quality 

Cohort 

McGeer

1972 45 d 15 po 18 Therapeutic benefit 

33% No therapeutic benefit 

61%: Slight subjective benefit, no objective change 

5%: Worsening of gait. 

PD ndddC

Rapin 

1988 120 d ~7 c po 38 Battery of 

cognitive tests

Significant improvement in 5 of 16 tests, including 

tests of visuo-spatial memory and organization, 

associative memory, and logical reasoning. 

No change in 11 other tests. 

Dementia

Low 

folate d 62ddC

 Higher score indicates better cognitive function.  Lower score indicates better cognitive function. d: days; N: 

number; NS: non-significant; nd: not documented; po, orally; wk: week; WAIS-R, Wechsler Adult Intelligence ScaleRevised 

a

 Part of Randt Memory Test. 

b

 <3 ng/mL. 

c

 Folinic acid 50 mg/week. 

d

 RBC folate <300 ng/mL. 

Combined B Vitamins Intervention Studies 

Study Descriptions. Six studies, including 3 RCTs83-85 and 3 uncontrolled cohort studies86-88

assessed the effects of a combination of B vitamins as interventions on cognitive function in 

elderly subjects. Four trials included subjects with AD and/or mixed dementia,83,85,86,88 one with 

cognitive impairment,87 and one without dementia.84 All studies used different daily doses of 

various B vitamins in the ranges of 0.8 to 15 mg folic acid or folate, 3 to 80 mg B6, and 0.1 to 2 

mg B12; all substantially over the US RDA. Three used a combination of folic acid , B6, and 

B12, two used folic acid and B12, and one used folate and B12. All but one study treated 

subjects with oral vitamin supplementation; Shaw 1971 used a combination of B12 injection and 

oral folate. All studies included subjects whose mean ages were greater than 70 years. The 

primary outcome for all studies was cognitive function. About 470 subjects were tested in six 

studies. All studies were of moderate to poor quality (2 B, 4 C). One study has broad 

applicability, four moderate, and two narrow applicability. 

Overall Effect. Five of the six studies found no significant change in cognitive function, 

generally measured with MMSE or WAIS, after combination B vitamin supplementation. 

 The single study to find a significant improvement, Nilsson 2001, was an uncontrolled cohort 

study. This study found significant changes in the cognitive score performance among subjects 

with mild-moderate dementia and elevated plasma homocysteine concentration with a significant 

global clinical improvement after vitamin intervention. There was a four point increase in the 

mean MMSE score from a baseline score of 17. However the same study failed to show any 

improvement among patients with severe dementia or those with mild-moderate dementia and 

normal plasma homocysteine levels with a mean baseline score of 21 after combined vitamin 

intervention. 
61 

 Lewerin 2005, a RCT, compared moderate doses of vitamins supplementation to placebo 

among ambulatory normal subjects, and measured cognitive function with a battery of nine tests. 

The placebo arm performed better in three of the tests compared to the actively treated group. 

Two other RCTs reported no significant changes in cognitive function in either intervention arms 

after vitamin supplementation. The remaining two cohort studies, Aisen 2003 and Lehmann 

2003, reported no observable differences after treatment. 

Interactions and Covariates. There was no dose related responses discussed in the studies. Only 

Nilsson 2001, an uncontrolled cohort study reported a difference in cognitive function with 

relation to severity of dementia, and with the levels of plasma homocysteine (<2.69 versus >2.69 

mg/L) after combined B vitamin intervention. This study also reported a significant improvement 

in alertness, orientation in time and space, recent memory and fewer clinical fluctuations among 

subjects with dementia after combined vitamin intervention. One RCT85 used a combination of 

B12 injection and oral folate among senile dementia with high and low RBC folate levels; 

remainder of the studies evaluated combined vitamin intervention among those with normal 

blood vitamin levels. There was no evidence across studies of differences in effect on tests of 

different cognitive domains. 

Summary. Six studies of moderate to poor quality reported data on the effect of combined B 

vitamin intervention among normal people, cognitively impaired, and those with AD and/or 

mixed dementia. The three RCTs found no benefit in the actively treated arm compared to 

placebo. Only one of the uncontrolled cohort studies found both statistically and clinically 

significant large benefit. However, interpretation of the cohort studies is difficult without a 

comparable control group given the variable course of dementia over time. The two other 

uncontrolled cohort studies reported no benefit after intervention. 
62

Table 14. Effect of combination B vitamin interventions on cognitive function 

Design Intervention Dose/day Change Net Change 

Control 

Author 

Year 

Duration 

 B1 (g) 

 B2 (mg) 

 Folate mg) 

 B6 (mg) 

 B12 (mg) 

Route N Test /Subtest 

Maximum Score 

Base value 

Value 

P value

Change 

Value 

P value 

Net Change 

RCT 

2 1 po 74 30 21 nd NS 

Placebo 75 MMSE 

2 1 po 74 70 27 nd NS 

Clarke 2003 

12 

wk 

Placebo 75 ADAS 

0.8 3 0.5 po 115 9 5.8 +0.2 .09 -0.1 NS 

Placebo 64 Digit Span Forward (WAIS)  5.9 +0.3 NS 

0.8 3 0.5 po 115 8 4.4 +0.25 .09 +0.03 NS 

Placebo 64 Digit Span Backward (WAIS)  4.6 +0.22 NS 

0.8 3 0.5 po 114 42 18. 5 +1.0 NS +0.2 NS 

Placebo 61 

Block Design (WAIS)  20.

0 +0.8 NS 

0.8 3 0.5 po 113 90 35. 1 +0.9 NS -1.4 .09 a

Placebo 62 

Digit Symbol (WAIS)  38.

0 +2.3 NS 

0.8 3 0.5 po 115 60 23. 3 +0.1 NS -1.4 .04 a

Placebo 61 

Identical Forms  24.

8 +1.5 NS 

0.8 3 0.5 po 113 14 6.9 +0.6 NS 0 NS 

Placebo 62 Visual Reproduction  7.0 +0.6 NS 

0.8 3 0.5 po 110 30 22. 5 +0.31 NS -1.0 .02 a

Placebo 61 

Synonyms  22.

4 +1.3 NS 

0.8 3 0.5 po 115 28 20. 3 +1.7 NS -1.7 NS 

Placebo 63 

Thurstone’s Picture Memory Test  21.

1 +2.4 NS 

0.8 3 0.5 po 113 30 15. 8 +1.5 NS +0.9 NS 

Lewerin 2005 

4 mo 

Placebo 62 

Figure Classification  16.

8 +0.6 NS 
63

Design Intervention Dose/day Change Net Change 

Control 

Author 

Year 

Duration 

 B1 (g) 

 B2 (mg) 

 Folate mg) 

 B6 (mg) 

 B12 (mg) 

Route N Test /Subtest 

Maximum Score 

Base value 

Value 

P value

Change 

Value 

P value 

Net Change 

12 

wk 15 1 b po IM 

 Placebo 

17 Dementia Scale  The means were unchanged in both groups 

12 

wk 15 1 b po IM Mild increase, not statistically significant 

Shaw 1971 

 Placebo 

17 

Blessed Information-Memory 

Concentration Test 

S

Hi
64

Table 14. Effect of combination B vitamin interventions on cognitive function (Continued) 

Design Intervention Dose/day Change Net Change 

Control 

Author 

Year 

Duration 

 B1 (g) 

 B2 (mg) 

 Folate mg) 

 B6 (mg) 

 B12 (mg) 

Route N Test /Subtest 

Maximum Score 

Base value 

Value 

P value

Change 

Value 

P value 

Net Change 

Population 

Cohort Aisen 2003 8 wk 5 50 1 po 63 MMSE  30 19.2 +0.1 NS AD 

5 1 11 30 21.3 -0.4 NS Mixed Dementia Hcy 

Placebo po 17 MMSE  17.2 +4.2 <.01 Mixed Dementia Hcy 

5 1 11 27 15.6 -0.8 NS Mixed Dementia Hcy 

Nilsson 2001 2 mo 

Placebo po 17 SKT  18.5 -3.9 <.01 Mixed Dementia Hcy 

Lehmann MMSE  26.3 +0.1 NS 2003 c 270 d d 10 80 2 po 30 CSF-tau 30 529 -39 NS Mild cognitive im

 Higher score indicates better cognitive function.  Lower score indicates better cognitive function. CSF: cerebrospinal fluid; d: days; H

intramuscular; MMSE, mini mental status examination; nd: not documented; NS: non-significant; po, orally; SKT: a short cognitive test fo

attention; WAIS: Wechsler Adult Intelligence Scale 

a Placebo better than B vitamin. b B12 injections of hydroxycobalamin 1000 mg daily for 1st week and weekly for 11 weeks thereafter. c Used 35 healthy controls for CSF tau; no data documented for controls. d Mean. Range = 110-740 days.
65 

Association of Dietary Intake Levels of B Vitamins to Age-Related 

Neurodegenerative Diseases 

 In this section, we summarize the findings from five (retrospective and prospective) 

longitudinal studies89-91 and five cross-sectional studies65,92-96 that examined the association 

between the dietary intake levels of B vitamins and cognitive function or the risk of age-related 

neurodegenerative diseases. We included all populations from longitudinal studies, while only 

non-institutionalized or free-living populations were included from cross-sectional studies in 

order to assess their “usual” dietary intake levels. All dietary assessment methods have certain 

strengths and limitations; thus it is important to choose an appropriate method depending on the 

study design and research questions.97 For example, a food record or diet recall is appropriate for 

estimating the mean dietary intakes in the study population. Food frequency questionnaire (FFQ) 

is a semi-quantitative instrument and it is designed to estimate the long-term usual intake. FFQ is 

good for ranking subjects’ intake levels, but might not be appropriate for estimating the mean 

dietary intake levels. 

Longitudinal Studies 

Study Descriptions. One prospective nested case-control study, three prospective cohort studies, 

and one retrospective case-control study examined the association between dietary intake levels 

of B vitamins and neurodegenerative diseases or cognitive function (Tables 15-17). Each study 

associated the B vitamin intake levels with different outcomes, including the risk of newly 

developed PD cases, rates of cognitive change per year, follow-up cognitive function examined 

by various cognitive tests, and a diagnosis of probable AD. Two studies were of good quality, 

one study was of moderate quality, and the other two studies were of poor quality. 

Overall Effects. Chen 2004 conducted a nested case-control study to investigate whether intake 

of folate or related B vitamins involved in folate and homocysteine metabolism was associated 

with PD risk, using two large cohorts in the US – the Health Professionals Follow-up study 

(1986-2000) and the Nurse’s Health Study (1980-1998).89 The two cohorts were analyzed 

separately and then pooled analyses were also performed. Participants’ dietary intakes were 

assessed by a food frequency questionnaire during the previous 12 months. It was found that 

controlling for age, smoking, alcohol consumption, caffeine intake and lactose intake, there were 

no significant associations found between the baseline intake of folate, vitamin B6, or vitamin 

B12 and relative risk of PD in either study. Several sensitivity analyses were also performed for 

different levels of folate intake. Individuals at either the low end (≤200 μg/day) or the high end 

(>1000 μg/day) of folate intake had a PD risk similar to that of people with normal folate intake, 

controlling for various possible confounders. Furthermore, in a separate analysis, supplemental 

intake of folate, vitamin B6, or vitamin B12 was also not related to the risk of PD. Compared 

with non-supplemented participants, individuals whose supplemental folate intake was more than 

400 μg per day had a pooled RR of 1.0. 

 Morris 2005 conducted a prospective longitudinal cohort study to examine the associations of 

dietary folate and vitamin B12 with 6-year cognitive change in the participants of the Chicago 

Health and Aging Project.98 Change in cognitive function measured at baseline, 3-year and 6-

year follow-ups, using the average z score of four tests: the East Boston Tests of immediate and 

delayed recall, the Mini-Mental State Examination, and the Symbol Digit Modalities Test. The 
66 

median dietary intake of folate ranged from 175 to 382 μg/day for first and last quintile 

respectively. The median intake of folate, from food and supplements, ranged from 186 to 742 

μg/day for first and last quintile respectively. At baseline, it was found that persons with high 

intake of total folate (from food and supplements) tended to have a more favorable risk profile 

for cognitive change (more years of education, higher baseline cognitive scores, and greater 

consumption of vitamin E and vitamin C) than persons with low intake. After a median followup of 5.5 years, unexpectedly, high folate intake from food sources and/or supplements was 

associated with a faster rate of cognitive decline in a mixed models adjusted for multiple risk 

factors. Further sensitivity analyses showed no change in the effect estimates after restricting the 

analyses in persons who reported poor health status or with low baseline cognitive scores 

(bottom 15% of the distribution) at baseline. Intake of vitamin B12, with or without vitamin 

supplementation, was not significantly associated with cognitive change in the multivariate 

model or with adjustment for folate intake (data not shown). 

 Part of Tucker 2005 study examined the association between dietary B6, B12 and folate 

intakes and 3-year changes in cognitive measures in the Veterans Affairs Normative Aging, a 

longitudinal cohort consists of 321 aging men at baseline.96 Cognitive function was assessed with 

the MMSE and on the basis of measures of memory, verbal fluency, and constructional praxis, 

which were adapted from the revised WAIS and the CERAD batteries at 2 time points. 

Improbable dietary intakes (total energy >16.75 or <2.51 MJ) were excluded from further 

analysis. Over a mean 3-year follow-up, changes in constructional praxis measured by spatial 

copying were significantly associated with dietary folate, B6 and B12. The mean dietary folate, 

B6 and B12 was 440 μg/day, 3.98 mg/day and 9.57 μg/day, respectively. Dietary folate remained 

independently protective against a decline in spatial copying score after adjustment for other 

vitamins and for plasma homocysteine. Dietary folate was also protective against a decline in 

verbal fluency. There was no other significant association found between dietary folate, B6, or 

B12 and changes in other cognitive measures. The major limitation of these analyses is that 

dependent biases might occur, since the dietary intakes and cognitive measures were both 

assessed by self-administered instruments. 

 Deijen 2003 conducted a prospective cohort study to examine the relation between nutritional 

intake and daily functioning in elderly people being evaluated in a psychogeriatric nursing 

home.90 During the study 60 percent of the dropouts “became ill” compared to 34 percent of the 

subjects who completed the study. Participants’ dietary intakes were assessed by a combination 

of a 3-day record and weighing-back methods at baseline, weeks 8, 16 and 24, recorded by 

nurses. An analysis was performed to test for associations with change in ZIG-scores. Two 

experimental groups were formed based on high (>1.0 mg/day) and low intakes (≤1.0 mg/day) of 

B6 compared to their median intakes at baseline. There were no interactions between intake 

groups and week, indicating that the high and low intake groups had the same pattern of ZIGscores across the 6-month experimental period. There was deterioration in cognitive, physical 

and social functioning with time. However, this study had several limitations. Dropouts had 

worse health status than completers; it is unclear whether the nurses who assessed exposure and 

outcomes were the same; and the restriction to nursing home residents limits applicability. 

 Mizrahi 2003 conducted a retrospective case-control study compared patients with AD to 

healthy controls.(Mizrahi, 2003 2188 /id} Both proxy and surrogate respondents of cases and 

controls were asked to recall their food consumptions using a food frequency questionnaire 

during three age periods: 20 to 39, 40 to 59 and 60 or more years old. It was found that those 

with AD had lower mean dietary vitamin B6 and folate intake compared to controls in the over 
67 

60 years of age period (P=0.05 and 0.01, respectively), but not in younger age periods. No 

statistically significant correlations were found between homocysteine levels and dietary vitamin 

B6 and folate intake in the three age periods for those with AD and controls. This study was 

deemed to be of poor quality due to serious recall biases. Specifically, controls might have had 

more accurate recalls than cases, because cases’ intakes were estimated by proxy or surrogate 

respondents, and all respondents might remember the food consumption during more recent age 

period better than distant age periods. Finally, the recall periods were too long to obtain accurate 

food consumption data. 

Summary. No significant associations were found between dietary intakes of B6 or B12 and PD, 

AD, cognitive functioning, or cognitive decline across three studies. One additional study found 

higher dietary intakes of B6, B12, and folate were associated with improvements in some, but 

not all, cognitive function measures. In three separate studies, folate intake was not associated 

with PD or AD; however, in one study, higher folate intake from food sources and/or 

supplements was associated with a faster rate of cognitive decline after adjusting for multiple 

risk factors. 
68

Table 15. Association between dietary intake levels of vitamin B6 and neurodegenerative diseases or cognitive function in long

Re

Author 

Year 

Country Baseline Population 

Baseline 

Mean Age (yr) N Study Design (Follow-up 

Duration) 

Dietary 

Assessment 

Method 

Outcomes 

Mean Daily Intake 

(mg/day) 

RR 

/OR, 

βi

Pb

(95%

Quintile 1 nd 1.0b RQuintile 2 nd 1.1 (0.8, Quintile 3 nd 1.3 (0.9, Quintile 4 nd 0.9 (0.7, 

Normal, all 30- 75 136,057 

Quintile 5 nd 1.0 (0.7, 

Quintile 1 3.6a 1.0b RQuintile 2 4.3a 1.3 (0.8, Quintile 3 5.6a 1.3 (0.9, Quintile 4 7.9a 0.8 (0.5, 

Normal, men 40- 75 47,341 

Quintile 5 22.1a 1.0 (0.6, 

Quintile 1 1.6a 1.0b RQuintile 2 1.9a 0.9 (0.5, Quintile 3 2.3a 1.4 (0.8, Quintile 4 3.3a 1.1 (0.7, 

Chen, 2004 US 

Normal, women 

30-

55 88,716 

Prospective 

nested casecontrol study 

(Mean follow-up 

12.7 yr in men & 

17.3 yr in 

women) 

Food frequency 

questionnaire, 

validated 

Risk of newly 

developed PD cases 

analyzed by Cox 

proportional hazard 

models 

Quintile 5 5.8a 1.1 (0.7, 

Constructional praxis: 

spatial copying, sum 

of drawings 

0.30j <.

Language: verbal 

fluency, no. correct 0.81j <.

Working memory: 

backward digit span, 

longest span recalled 

0.04 j N

Recall memory: word 

lists, total of 3 trials 0.21j N

Tucker, 2005 Normal, men 67 241- 287 

Prospective 

longitudinal 

cohort study 

(mean 3 yr) 

Food frequency 

questionnaire, 

validated 

Mini-Mental State 

Examination 

4.0 ± 7.2 SD 

(range 0.5-85.5) 

(N=321) 

-0.05j N

Low intake ≤1.0 Deijen, g

2003 Netherlands 

Mixed 83 90 

Prospective 

cohort study 

(6 mo) 

3-day food 

records, weighing 

food 

Zorg Index Geriatrie 

(ZIG)-scalesf  High intake >1.0g nd N
69

Table 15 Association between dietary intake levels of vitamin B6 and neurodegenerative diseases or cognitive function 

(Continued) 

R

Author 

Year 

Country 

Baseline 

Population 

Baseline 

Mean Age (yr) N Study Design (Follow-up Duration) Dietary Assessment Method Outcomes Mean Daily Intake (mg/day) RR /OR, βi

20-39 yr 0.90d 40-59 yr 0.90d 

ADf 

 74 <64c

60+ yr 0.96d

nd 

20-39 yr 0.90d 40-59 yr 0.95d 

Mizrahi, 2003 US Normal 75 <64c

Retrospective casecontrol study 

(3 age periods: 20-39, 

40-59; 60+ yr old) 

Food frequency 

questionnaire 

Diagnosis of probable 

AD, fulfilling 

NINCDS/ADRDA 

criteria 

60+ yr 1.10d

nd 

 Lower score indicates better cognitive function. Ref=reference group for comparisons a Median intake b All RRs were adjusting for age, smoking, total energy intake, alcohol consumption, caffeine intake, and lactose intake c Missing data on dietary intake for some of the participants resulted in different sample sizes for the various time periods d Values were estimated from graphs. Intake amount is per 1000 Kcal e Two-sample t-tests were used to compare the mean levels of dietary folate or vitamin B6 for AD patients and controls (reference group

separately. These analyses were not adjusted for any confounders f The ZIG-scale consists of ZIG-A scale (cognitive functioning), ZIG-B scale (social functioning) and the ZIG-C scale (social functioning). 

scales are from 6 to 24. The higher the score, the worse the outcome. For the purpose of this review, we only look at the results of ZIG-A 

g Mean intake was averaged for each subject across the 12 assessments: 3 across 1 week, 4 across 24 weeks h Repeated measurements analyses were carried out with ZIG-scores as repeated measurement factor and 3 comparisons were separa

low/high intake groups of vitamin B6 as between subjects factor 

i Slope for the multivariate linear regression model j Final cognitive measures regressed onto baseline diet, adjusted for baseline cognitive measures, age, education, smoking, alcohol inta

no), systolic blood pressure, time of second measure relative to folic acid fortification, time interval between the 2 cognitive measures, an

outcomes and dietary intake measures were log-transformed. 
70

Table 16. Association between dietary intake levels of vitamin B12 and neurodegenerative diseases or cognitive function in lon

R

Author 

Year 

Country Baseline Population 

Baseline 

Mean Age (yr) N Study Design (Follow-up Duration) Dietary Assessment Method Outcomes Mean Daily Intake (μg/day) RR /OR, 

βd

Quintile 1 nd 1.0b Quintile 2 nd 1.2 (Quintile 3 nd 1.0 (Quintile 4 nd 0.9 (

Normal, all 30- 75 136,057 

Quintile 5 nd 1.0 (

Quintile 1 8.6a 1.0b Quintile 2 9.4a 1.1 (Quintile 3 10.4a 0.8 (Quintile 4 13.1a 0.9 (

Normal, men 40- 75 47,341 

Quintile 5 21.9a 1.0 (

Quintile 1 5.5a 1.0b Quintile 2 6.1a 1.5 (Quintile 3 6.8a 1.5 (Quintile 4 9.2a 1.0 (

Chen, 2004 US 

Normal, women 

30-

55 88,716 

Prospective nested 

case-control study 

(Mean 12.7 yr in 

men & 17.3 yr in 

women) 

Food frequency 

questionnaire, 

validated 

Risk of newly 

developed PD cases 

analyzed by Cox 

proportional hazard 

models 

Quintile 5 17.1a 1.0 (

Constructional praxis: spatial copying, sum of drawings 

0.37c 

Language: verbal fluency, no. correct 0.38c Working memory: backward digit span, longest span recalled 

0.12c 

Recall memory: word lists, total of 3 trials -0.01c 

Tucker, 2005 Normal, men 67 241- 287 Prospective longitudinal cohort study (mean 3 yr) Food frequency questionnaire, validated 

Mini-Mental State Examination 

9.6 ± 5.7 SD 

(range 1.4-57.0) 

(N=321)

0.14c 

Ref=reference group for comparisons a Median intake b All RRs were adjusting for age, smoking, total energy intake, alcohol consumption, caffeine intake, and lactose intake c Final cognitive measures regressed onto baseline diet, adjusted for baseline cognitive measures, age, education, smoking, alcohol inta

no), systolic blood pressure, time of second measure relative to folic acid fortification, time interval between the 2 cognitive measures, an

outcomes and dietary intake measures were log-transformed. d Slope for the multivariate linear regression model 
71

Table 17. Association between dietary intake levels of folate and neurodegenerative diseases or cognitive function in longitudi

R

Author 

Year 

Country Baseline Population 

Baseline 

Mean Age (yr) N Study Design (Follow-up Duration) Dietary Assessment Method Outcomes Mean Daily Intake (μg/day) RR /OR, 

βi

P

(9

Quintile 1 nd 1.0b Quintile 2 nd 1.2 (0.Quintile 3 nd 1.4 (1.Quintile 4 nd 1.3 (0.

Normal, all 30- 75 136,057 

Quintile 5 nd 1.2 (0.

Quintile 1 244a 1.0b Quintile 2 317a 1.2 (0.Quintile 3 388a 1.4 (0.Quintile 4 517a 1.2 (0.

Normal, men 40- 75 47,341 

Quintile 5 841a 1.1 (0.

Quintile 1 158a 1.0b Quintile 2 217a 1.3 (0.Quintile 3 277a 1.6 (0.Quintile 4 393a 1.5 (0.

Chen, 2004 US 

Normal, women 

30-

55 88,716 

Prospective nested 

case-control study 

(Mean 12.7 yr in 

men & 17.3 yr in 

women) 

Food frequency 

questionnaire, 

validated 

Risk of newly 

developed PD cases 

analyzed by Cox 

proportional hazard 

models 

Quintile 5 699a 1.4 (0.

Quintile 1 186a -- Quintile 2 251a -0.01h Quintile 3 311a -0.01h Quintile 4 419a -0.02h Quintile 5 742a -0.02h Quintile 1 175g,a -- Quintile 2 227g,v -0.01h Quintile 3 258g,a -0.01h Quintile 4 312g,a -0.01h Quintile 5 382g,a -0.02h 

0 -- 

1-200 -0.01h 

201-399 -0.01h 

400 -0.01h 

Morris, 2005 US 

Normal, all 74 3,718 

Prospective 

longitudinal cohort 

study (median 5.5 

yr) 

Food frequency 

questionnaire, 

validated 

Rates of cognitive 

changej per year 

analyzed by 

multivariate mixed 

effect model 

Supplement 

dose 

401-1200 -0.03h 
72

Table 17 Association between dietary intake levels of folate and neurodegenerative diseases or cognitive function in longitudin

R

Author 

Year 

Country 

Baseline 

Population 

Baseline 

Mean Age (yr) N Study Design (Follow-up Duration) Dietary Assessment Method Outcomes Mean Daily Intake (μg/day) RR /OR, βi

Constructional praxis: 

spatial copying, sum 

of drawings 

0.67k 

Language: verbal 

fluency, no. correct 1.44k 

Working memory: 

backward digit span, 

longest span recalled 

0.11k 

Recall memory: word 

lists, total of 3 trials 0.31k 

Mini-Mental State 

Examination 

440 ± 202 SD 

(range 80-1216) 

(N=321) 

0.08k 

Tertile 1 <339 -0.55l Tertile 2 339-523 -0.25m 

Tucker, 2005 Normal, men 67 241- 287 Prospective longitudinal cohort study (mean 3 years) Food frequency questionnaire, validated 

Change in figure 

copying score Tertile 3 >523 +0.25m 

20-39 yr 155d 40-59 yr 170d 

ADf 

 74 <64c

60+ yr 210d

nd 

20-39 yr 150d 40-59 yr 150d 

Mizrahi, 2003 US Normal 75 <64c

Retrospective casecontrol study 

(3 age periods: 20-39, 

40-59; 60+ yr old) 

Food frequency 

questionnaire 

Diagnosis of probable 

AD, fulfilling 

NINCDS/ADRDA 

criteria 

60+ yr 155d

nd 

Ref=reference group for comparisons a Median intake b All RRs were adjusting for age, smoking, total energy intake, alcohol consumption, caffeine intake, and lactose intake c Missing data on dietary intake for some of the participants resulted in different sample sizes for the various time periods d Values were estimated from graphs. Intake amount is per 1000 Kcal e Two-sample t-tests were used to compare the mean levels of dietary folate or vitamin B6 for AD patients and controls (reference group

separately. These analyses were not adjusted for any confounders f The ZIG-scale consists of ZIG-A scale (cognitive functioning), ZIG-B scale (social functioning) and the ZIG-C scale (social functioning). 

scales are from 6 to 24. The higher the point, the worse the outcome. For the purpose of this review, we only look at the results of ZIG-A 

g Folate from food intake only (or excluding intake from supplements) h Multiple-adjusted model includes terms including age, quintiles of folate intake, time, total energy, sex, education, race, vitamin E intake 

intake, and time interactions with all covariates. The model from folate intake from food sources also includes terms for multivitamin use 

i Slope for the multivariate linear regression model j Changes in the computed z scores for the 4 cognitive tests and averaged the scores for a global measure of cognitive function. The 4 c

East Boston Tests of immediate and delayed recall, the Mini-Mental State Examination, and the Symbol Digit Modalities Test of perceptu
73 

k

 Final cognitive measures regressed onto baseline diet, adjusted for baseline cognitive measures, age, education, 

smoking, alcohol intake, BMI, diabetes (yes or no), systolic blood pressure, time of second measure relative to folic 

acid fortification, time interval between the 2 cognitive measures, and total energy intake. All outcomes and dietary 

intake measures were log-transformed. 

l

 Mean change in score from baseline 

m Estimated value from graphs 

Cross-Sectional Studies 

Study Descriptions. Five cross-sectional studies examined the association between the dietary 

intake levels of B vitamins and cognitive function or the risk of age-related neurodegenerative 

disease.65,92-95 Of the five studies, three were of fair quality and two were of poor quality. 

Overall Effects 

Thiamine (B1). Three studies associated participants’ dietary intake levels of thiamine to their 

cognitive function scores.92,93,95 One additional study compared the dietary intake levels of 

thiamine in participants with AD to that in normal participants (Table 18).94 No statistically 

significant association was found between the dietary intake levels of thiamine and cognitive 

function scores, except for Goodwin 1983 that found that participants who were in bottom 5 

percent of thiamine intake levels had significantly worse Wechsler verbal memory test scores 

than those who were in the top 90 percent. Renvall 1989 found that participants with AD had 

similar dietary intake levels of thiamine as normal participants. 

Riboflavin (B2). The same four studies that evaluated thiamine also assessed participants’ 

dietary intake levels of vitamin B2 (Table 19).92-95 Similar results were found except that 

Goodwin 1983 found that participants who were in bottom 10 percent of vitamin B2 intake 

levels had significantly worse Wechsler verbal memory test scores than those who were in the 

top 90 percent. In addition, Lee 2001 found that, adjusting for age, the dietary intake levels of 

vitamin B2 increased with MMSE scores among women, but not among men. 

Pyridoxine (B6). Three studies associated participants’ dietary intake levels of vitamin B6 with 

cognitive function scores (Table 20).65,92,95 No statistically significant association was found 

between the dietary intake levels of vitamin B6 and cognitive function scores, except for 

Goodwin 1983, which found that participants who were in bottom 10 percent, but not the bottom 

5 percent, of B6 intake levels had significantly worse Wechsler verbal memory test scores than 

those who were in the top 90 percent. 

Cyanocobalamin (B12). Three studies associated participants’ dietary intake levels of vitamin 

B12 to their cognitive function scores (Table 21).65,92,95 One additional study compared the 

dietary intake levels of vitamin B12 in participants with AD to that in normal participants.94 No 

statistically significant association was found between the dietary intake levels of vitamin B12 

and cognitive function scores or AD. 

Folate. The same four studies that evaluated vitamin B12 intake also tested folate intake (Table 

22)65,92,94,95 No statistically significant association was found between the dietary intake levels of 

folate and cognitive function scores, except for Goodwin 1983 that found that participants who 

were in bottom 5 percent of folate intake levels had significantly worse Wechsler verbal memory 
74 

test scores than those who were in the top 90 percent. Renvall 1989 found that participants with 

AD had similar dietary intake levels of folate as normal participants. 

Summary. Among the five studies, only two found any significant associations between vitamin 

B intake and cognitive function scores. One study found that subjects with low intake of vitamins 

B1, B2, B6, and folate, but not vitamin B12, scored significantly worse on verbal memory than 

those with relatively high intake levels. One study also found association between vitamin B2 

intake and MMSE score in women, but not in men. No association between dietary intake of B12 

and cognitive function or diagnosis of AD was found in all five studies. 
75

Table 18. Association between dietary intake of vitamin B1 (thiamine) and cognitive function in cross-sectional studies 

Re

Author 

Year 

Country Population 

Mean Age 

(yr) N Dietary 

Assessment 

Method 

Subgroups Mean Cognitive Score, 

Cognitive Score Used, 

or Cut-off 

Vitamin B1 

Intake 

(mg/day) 

Mean±SD 

n r 

All subjects Wechsler verbal memory test (WMT)  nd 260 -0.02 Mean intake ≤5% WMT score  = ~4.8f nd nd Mean intake ≤10% WMT score  = ~5.3f nd nd 

Goodwin, 1983 US 

Normal 72 260 3-day food records, weighing food 

Mean intake >90% WMT score  = ~6.2f nd nd 

MMSE  ≥ 28a 1.12 ± 0.34 nd Age<75th %tile MMSE  < 28 1.05 ± 0.29 nd MMSE≥28 1.12 ± 0.44 nd 

Requejo, 2003 Spain 

Normal ≥65 168 5-day food records, weighting food 

Age≥75th %tile MMSE< 28 0.96 ± 0.23 nd 

Normal MMSE-K  ≥ 24 0.95 ± 0.35 136 

Normal, men 72 210 Inadequate MMSE-K  19-24 0.91 ± 0.34 48 

Poor MMSE-K  ≤ 19 0.82 ± 0.27 26 

0.083c 

Normal MMSE-K  ≥ 24 0.91 ± 0.39 86 Inadequate MMSE-K  19-24 0.90 ± 0.63 79 

Lee, 2001 Korea 

Normal, women 

70 239 

Single 24-hr dietary 

recall 

Poor MMSE-K  ≤ 19 0.71e ± 0.35 74 

0.13c 

SDATd 77 <22b Renvall, SDAT nd 1.40 ± 0.50 15 

1989 US Normal 71 <41b 3-day food records Normal nd 1.20 ± 0.40 33  Higher score indicates better cognitive function.  Lower score indicates better cognitive function. %tile=percentile; SDAT=senile dem

type; Ref=reference group for the comparisons; MMSE-K= Mini-Mental State Examination for Koreans ↑ Increase of the intake level correlate with a better outcome, or decrease of the intake level correlate with a worse outcome 

↔ No association between the intake level and the outcome ↓ Increase of the intake level correlate with a worse outcome 

a Folstein’s MMSE was used. Points are awarded between 0 and 35, with 28 or more considered as normal. b Only subjects who had both dietary and biochemical data were analyzed. c Controlling for age d Free living subjects 

e Mean was significantly lower (Duncan’s multiple other groups. f Values were estimated from graphs g The study also performed a multivariate analysis 

sex of the subject and the correlation remained no

h Adjusted for unequal variances
76

Table 19. Association between dietary intake of vitamin B2 (riboflavin) and cognitive function in cross-sectional studies 

R

Author 

Year 

Country Population 

Mean Age (yr) N Dietary Assessment Method Subgroups Mean Cognitive Score, Cognitive Score Used, or Cut-off Vitamin B2 Intake (mg/day) Mean±SD n r 

All subjects Wechsler verbal memory test (WMT)  nd 260 0.02 Mean intake ≤5% WMT score  = ~4.5f nd nd Mean intake ≤10% WMT score  = ~4.25f nd nd 

Goodwin, 1983 US 

Normal 72 260 3-day food records, weighing food 

Mean intake >90% WMT score  = ~6.3f nd nd 

MMSE  ≥ 28a 1.43 ± 0.40 nd Age<75th %tile MMSE  < 28 1.39 ± 0.35 nd MMSE  ≥ 28 1.52 ± 0.43 nd 

Requejo, 2003 Spain 

Normal ≥65 168 5-day food records, weighting food 

Age≥75th %tile MMSE  < 28 1.46 ± 0.38 nd 

Normal MMSE-K  ≥ 24 0.87 ± 0.46 136 

Normal, men 72 210 Inadequate MMSE-K  19-24 0.77 ± 0.37 48 

Poor MMSE-K  ≤ 19 0.74 ± 0.32 26 

+0.08c 

Normal MMSE-K  ≥ 24 0.68 ± 0.33 86 Inadequate MMSE-K  19-24 0.72 ± 0.50 79 

Lee, 2001 Korea 

Normal, women 

70 239 

Single 24-hr dietary 

recall 

Poor MMSE-K  ≤ 19 0.50e ± 0.32 74 

+0.11c 

SDATd 77 <22b Renvall, SDAT nd 1.60 ± 0.60 14 

1989 US Normal 71 <41b 3-day food records Normal nd 1.50 ± 0.60 37  Higher score indicates better cognitive function.  Lower score indicates better cognitive function. %tile=percentile; Ref=reference gro

SDAT=senile dementia of the Alzheimer’s type; MMSE-K= Mini-Mental State Examination for Koreans ↑ Increase of the intake level correlate with a better outcome, or decrease of the intake level correlate with a worse outcome 

↔ No association between the intake level and the outcome ↓ Increase of the intake level correlate with a worse outcome 

a Folstein’s MMSE was used. Points are awarded between 0 and 35, with 28 or more considered as normal. b Only subjects who had both dietary and biochemical data were analyzed. c Controlling for age d Free living subjects 

e Mean was significantly lower (Duncan’s multiple other groups. f Values were estimated from graphs g The study also performed a multivariate analysis 

sex of the subject and the correlation remained no

h Adjusted for unequal variances
77

Table 20. Association between dietary intake of vitamin B6 (pyridoxine) and cognitive function in cross-sectional studies 

Re

Author 

Year 

Country Population 

Mean Age (yr) N Dietary Assessment Method Subgroups Mean Cognitive Score, Cognitive Score Used, or Cut-off Vitamin B6 Intake (mg/day) Mean±SD n r 

All subjects Wechsler verbal memory test (WMT)  nd 260 -0.02 Mean intake ≤5% WMT score  = ~5.5f nd nd Mean intake ≤10% WMT score  = ~4.8f nd nd 

Goodwin, 1983 US 

Normal 72 260 

3-day food 

records, weighing 

food 

Mean intake >90% WMT score  = ~6.2f nd nd 

MMSE  ≥ 28 Age<75th a 1.40 ± 0.39 nd 

%tile MMSE  < 28 1.39 ± 0.32 nd 

MMSE  ≥ 28 1.36 ±0.48 nd 

Requejo, 2003 Spain 

Normal ≥65 168 

5-day food 

records, 

weighting food Age≥75th

%tile MMSE < 28 1.40 ±0.31 nd 

Intake in 1st

quartile 1.20 ± 0.20 nd 

Intake in 2nd

quartile 1.60 ±0.10 nd 

Intake in 3rd

quartile 2.10 ±0.10 nd 

Bryan, 2002 Australia 

Normal 74 75 

Food frequency 

questionnaire, 

validated 

Intake in 4th

quartile 

Digit Symbol-Coding, Digit Span-Backwards, Digit-Symbol-Coding, and Vocabulary from Wechsler Adult Intelligence Scale-III; Stroop Test; Verbal Fluency; Initial Letter Fluency 



2.80 ±0.40 nd 

 Higher score indicates better cognitive function.  Lower score indicates better cognitive function. %tile=percentile; Ref=reference gro

↑ Increase of the intake level correlate with a better outcome, or decrease of the intake level correlate with a worse outcome 

↔ No association between the intake level and the outcome ↓ Increase of the intake level correlate with a worse outcome

a Folstein’s MMSE was used. Points are awarded between 0 and 35, with 28 or more considered as normal. 

f Values were estimated from graphs g The study also performed a multivariate analysis controlling for age and sex of the subject and the correlation remained not significant. h Adjusted for unequal variances 
78

Table 21. Association between dietary intake of vitamin B12 and cognitive function in cross-sectional studies 

Author 

Year 

Country Population 

Mean Age (yr) N Dietary Assessment Method Subgroups Mean Cognitive Score, Cognitive Score Used, or Cut-off Vitamin B12 Intake (μg/day) Mean±SD n r 

All subjects Wechsler verbal memory test (WMT)  nd 260 0.0Mean intake ≤5% WMT score  = ~5.8 f nd nd Mean intake ≤10% WMT score  = ~5.9f nd nd 

Goodwin, 1983 US 

Normal 72 260 

3-day food 

records, weighing 

food 

Mean intake >90% WMT score  = ~6.1f nd nd 

MMSE  ≥ 28 Age<75th a 7.3 ± 7.9 nd 

%tile MMSE  < 28 5.9 ± 5.6 nd 

MMSE  ≥ 28 7.3 ± 5.4 nd 

Requejo, 2003 Spain 

Normal ≥65 168 

5-day food 

records, weighting 

food Age≥75th

%tile MMSE  < 28 7.4 ± 8.0 nd 

Intake in 1st

quartile 2.1 ±0.6 nd 

Intake in 2nd

quartile 3.3 ± 0.3 nd 

Intake in 3rd

quartile 4.2 ± 0.4 nd 

Bryan, 2002 Australia 

Normal 74 75 

Food frequency 

questionnaire, 

validated 

Intake in 4th

quartile 

Digit Symbol-Coding, Digit Span-Backwards, Digit-Symbol-Coding, and Vocabulary from Wechsler Adult Intelligence Scale-III; Stroop Test; Verbal Fluency; Initial Letter Fluency 



8.4 ± 5.2 nd 

SDATd 77 <22b Renvall, SDAT nd 2.3 ± 1.8 21 

1989 US Normal 71 <41b

3-day food 

records Normal nd 2.9 ± 2.3 22 

 Higher score indicates better cognitive function.  Lower score indicates better cognitive function. %tile=percentile; Ref=reference gro

↑ Increase of the intake level correlate with a better outcome, or decrease of the intake level correlate with a worse outcome 

↔ No association between the intake level and the outcome ↓ Increase of the intake level correlate with a worse outcome

a Folstein’s MMSE was used. Points are awarded between 0 and 35, with 28 or more considered as normal. 

b Only subjects who had both dietary and biochemical data were analyzed. d Free living subjects f Values were estimated from graphs g The study also performed a multivariate analysis controlling for age and sex of the subject and the correlation remained not significant. h Adjusted for unequal variances 
79

Table 22. Association between dietary intake of folate and cognitive function in cross-sectional studies 

Re

Author 

Year 

Country Population 

Mean Age (yr) N Dietary Assessment Method Subgroups Mean Cognitive Score, Cognitive Score Used, or Cut-off Folate Intake (μg/day) Mean±SD n r 

All subjects Wechsler verbal memory test (WMT)  nd 260 -0.06 Mean intake ≤5% WMT score  = ~4.5f nd nd Mean intake ≤10% WMT score  = ~5.4f nd nd 

Goodwin, 1983 US 

Normal 72 260 

3-day food 

records, weighing 

food 

Mean intake >90% WMT score  = ~6.15f nd nd 

MMSE  ≥ 28 Age<75th a 202 ± 74 nd 

%tile MMSE  < 28 183 ± 61 nd 

MMSE  ≥ 28 223 ± 114 nd 

Requejo, 2003 Spain 

Normal ≥65 168 

5-day food 

records, 

weighting food Age≥75th

%tile MMSE  < 28 181 ± 64 nd 

Intake in 1st

quartile 203 ± 26 nd 

Intake in 2nd

quartile 266 ± 13 nd 

Intake in 3rd

quartile 326 ± 19 nd 

Bryan, 2002 Australia 

Normal 74 75 

Food frequency 

questionnaire, 

validated 

Intake in 4thquartile 

Digit Symbol-Coding, Digit Span-Backwards, Digit-Symbol-Coding, and Vocabulary from Wechsler Adult Intelligence Scale-III; Stroop Test; Verbal Fluency; Initial Letter Fluency 



467 ± 79 nd 

SDATd 77 <22b Renvall, SDAT nd 169 ±74 27? 

1989 US Normal 71 <41b

3-day food 

records Normal nd 186 ± 71 10 

 Higher score indicates better cognitive function.  Lower score indicates better cognitive function. %tile=percentile; Ref=reference gro

?=value doesn’t make sense perhaps due to reporting error ↑ Increase of the intake level correlate with a better outcome, or decrease of the intake level correlate with a worse outcome 

↔ No association between the intake level and the outcome ↓ Increase of the intake level correlate with a worse outcome

a Folstein’s MMSE was used. Points are awarded between 0 and 35, with 28 or more considered as normal. 

b Only subjects who had both dietary and biochemical data were analyzed. d Free living subjects f Values were estimated from graphs g The study also performed a multivariate analysis controlling for age and sex of the subject and the correlation remained not significant. h Adjusted for unequal variances 
80 

Association of Tissue Levels of B Vitamins to Age-Related 

Neurodegenerative Diseases 

Thiamine (Vitamin B1) Level Association Studies 

Study Descriptions. Eight cross-sectional studies examined the association of thiamine levels 

with diagnosis or cognitive function.99-106 Four of these studies measured serum, plasma, and 

RBC levels of thiamine among AD, non-AD, PD, and cognitively impaired subjects (Table 23). 

Four other studies reported the plasma, cerebrospinal fluid (CSF), and brain levels of thiamine 

diphosphate (TDP), the active form of thiamine in the brain (Table 24). The sample size for the 

cross-sectional studies ranged from 34 to 290. The two studies by Mastrogiacoma 1996 and 

Molina 2002, which reported brain or CSF levels of thiamine derivatives (free thiamine, total 

thiamine, thiamine monophosphate, thiamine diphosphate), compared the levels between AD and 

normal controls. Jimenez-Jimenez 1999 compared the CSF levels of thiamine derivatives 

between PD and controls. Snowdon 2000 compared the thiamine levels from stored blood within 

a subset of AD subjects who had histologically significant and non-significant lesions in the 

brain at autopsy. All studies were graded moderate to poor quality (3 B, 5 C). Three studies have 

broad applicability, two moderate, and three narrow applicability. 

Overall Effect. Four studies evaluated plasma and/or RBC thiamine or thiamine pyrophosphate 

(TPP), two of which found significantly greater deficiency among AD subjects compared to PD 

or controls (Table 23). Four other studies evaluated thiamine or thiamine derivatives in CSF, 

plasma, and cerebral cortex (Table 24). Two of these reported significantly reduced levels of 

thiamine derivatives in plasma or cerebral cortex among AD subjects and one among subjects 

with PD. 

 Gold 1995 examined the thiamine levels in the plasma and RBCs and found significantly low 

plasma thiamine levels and a high prevalence of plasma thiamine deficiency, but not for RBC 

thiamine, among probable AD, compared to non-AD subjects. A subsequent publication by the 

same author (Gold 1998) evaluated thiamine levels in the plasma and RBC thiamine among AD 

and PD subjects, and reported similar significantly lower levels and higher prevalence of plasma 

thiamine among AD subjects. The plasma level of thiamine among PD subjects was normal. 

Assantachai 1997 estimated serum levels and reported a high, but non-significant prevalence of 

thiamine deficiency among cognitively impaired compared to normal elderly subjects. Scillepi 

1984 reported normal mean thiamine levels among AD and non-AD subjects. 

 Jimenez-Jimenez 1999 compared CSF levels of thiamine and its phosphate esters among PD 

patients and normal controls. All thiamine derivatives in the CSF except free thiamine were 

normal among PD patients. Molina 2002 compared subjects with AD to normal controls. This 

study examined CSF and plasma levels of thiamine derivatives and reported significantly lower 

plasma levels of thiamine derivatives among AD subjects. Among a subset of AD patients 

annual mean decreases in MMSE score was assessed and there were no significant differences in 

mean MMSE scores with high versus low thiamine levels. Mastrogiacoma 1996 examined 

thiamine derivatives in autopsied cerebral cortex among AD and normal subjects. The mean 

levels of TDP in the temporal, parietal, occipital areas of cerebral cortex were slightly, but 

significantly reduced by 18 to 21 percent among AD subjects compared to normal subjects. The 

levels of other thiamine derivatives were normal among AD subjects. Snowdon 2000 described a 

negative, but non-significant correlation of serum thiamine levels with severity of cerebral cortex 
81 

atrophy among AD subjects with histologically significant lesions. AD subjects with 

histologically non-significant lesions had a positive, but non-significant correlation of serum 

thiamine levels with severity of atrophy of the cerebral cortex. 

Interactions and Covariates. Gold 1998 (Table 23) performed secondary analyses excluding 

four PD patients less than 60 years of age, matching the two groups for age. They found 

significant differences in both the plasma thiamine levels and the prevalence of thiamine 

deficiency (defined as plasma or RBC thiamine values below the range of normal for their 

respective age group) between AD, and PD subjects. Snowdon 2000 (Table 24) adjusted age as a 

potential confounder in the correlation analyses, but other studies did not adjust for potential 

confounders. No longitudinal studies evaluated the association of thiamine and cognitive 

function. 

Summary. Overall, eight cross-sectional studies evaluated levels of thiamine among AD, 

cognitively impaired and PD patients. Three studies reported significantly reduced mean 

thiamine or TDP levels in the plasma and brain among AD subjects, and one reported similar 

reduction in mean levels of thiamine derivative among PD subjects. None of the studies that 

showed significant results adjusted for potential confounders. The remaining four studies found 

no differences between the investigated groups.

Table 23. Association of thiamine (vitamin B1) levels and prevalence of thiamine deficiency with cognitive 

function 

 Thiamine Level (ng/mL) Thiamine 

deficient Author 

Year 

Population 

Mean Age 

(yr) 

N 

Tissue Mean SD Normal 

Range P a % P b

 Applicability  Quality 

Assantachai Cognitive impaired 69 63 12.4 8.8 30.2 

1997 Normal 69 138 Blood 10.9 7.7 0-15%c NS NS ddd B 

AD 78 17 7.5 4.1 65 

PD 71 33 Plasma 11.1 4.1 11-12 d <.001 11 

AD 78 17 149.9 34.6 

Gold 

1998 

PD 71 33 RBC 146.8 43.1 

140-

146 e NS nd 

<.001 d B 

Scileppi AD nd 55 46 4 

1984 Non-AD nd 58 Plasma 48 4 >25 NS nd dd C 

AD 78 17 7.5 4.1 65 

Non-AD 75 17 Plasma 12.6 5.4 11-12 d .002 12 <.001 

AD 78 17 149.9 34.6 18 

Gold 

1995 

Non-AD 75 17 RBC 168.0 47.8 

140-

146 e .07 0 NS 

dd C 

SD: standard deviation; NS: non-significant 

a P values for comparing mean levels of thiamine. b P values for comparing percent with thiamine deficiency. c

 Blood level of thiamine pyrophosphate (TPP). 

d

 Plasma: Normal mean (range): Age 61-80: 12.0 (8-26); Age 81+: 11.0 (10-12.6) ng/mL. e

 RBC: Normal mean (range): Age 61-80: 146.0 (89-205); Age 81+: 140.0 (131-163) ng/mL.
82

Table 24. Association of levels of thiamine or thiamine derivatives (vitamin B1) with diagnoses of age related neurocognitive di

B Vitamin Level 

Author 

Year Population 

 Mean Age 

(yr) N Thiamine or thiamine derivative 

description 

Tissue 

(units) Mean SD 

Correlation 

 or % of 

Change a

AD with lesions b 91 15 142 36 r=-0.49 

Snowdon 2000 AD without 

lesions c 91 15 B1 level correlating with atrophy Serum nmol/L 148 30 r=+0.05 

AD 73 33 7.29 6.98 Normal 70 32 Total thiamine 9.46 4.52 AD 73 33 1.17 3.03 Normal 70 32 Free thiamine 2.20 3.20 AD 73 33 3.57 3.84 Normal 70 32 

TMP 

4.30 2.40 

AD 73 33 2.55 1.70 

Molina 2002 

Normal 70 32 

TDP 

CSF 

nmol/L 

3.21 2.28 

AD 73 33 4.75 7.72 Normal 70 32 Total thiamine 7.88 5.79 AD 73 33 1.16 1.21 Normal 70 32 Free thiamine 2.61 2.93 AD 73 33 1.32 2.02 Normal 70 32 

TMP 

2.20 3.20 

AD 73 33 2.22 1.74 

Molina 2002 

Normal 70 32 

TDP 

Plasma 

nmol/L 

3.23 1.87 

PD 64 24 9.1 6.4 Normal 63 40 Total thiamine 9.3 5.1 PD 64 24 0.9 1.3 Normal 63 40 Free thiamine 1.9 1.4 PD 64 24 3.9 3.0 Normal 63 40 

TDP 

3.1 2.3 

PD 64 24 4.3 3.3 

JimenezJimenez 1999 

Normal 63 40 

TMP 

CSF 

nmol/L 

4.3 2.9 
83

Table 24. Association of levels of thiamine or thiamine derivatives (vitamin B1) with diagnoses of age related neurocognitive di

B Vitamin Level 

Author 

Year Population 

 Mean Age 

(yr) N Thiamine or thiamine derivative 

description 

Tissue 

(units) Mean SD 

Correlation 

 or % of 

Change a

AD 73 20 27.2 1.4 -11% Normal 70 18 

Total thiamine 

30.7 1.3 

AD 73 20 9.0 0.7 -1% Normal 70 18 Thiamine 9.0 0.7 AD 73 20 3.4 0.3 +13% Normal 70 18 

TMP 

3.0 0.4 

AD 73 20 14.8 0.8 -20% 

Mastrogiacoma 1996 

Normal 70 18 

TDP 

Temporal 

cortex 

pmol/mg 

18.6 0.9 

AD 73 20 29.5 1.4 -5% Normal 70 18 Total thiamine 31.1 1.3 AD 73 20 9.9 0.8 +9% Normal 70 18 Thiamine 9.1 0.6 AD 73 20 3.9 0.4 +26% Normal 70 18 

TMP 

3.1 0.3 

AD 73 20 15.7 0.7 -18% 

Mastrogiacoma 1996 

Normal 70 18 

TDP 

Parietal 

cortex 

pmol/mg 

19.1 1.0 

AD 73 20 27.9 1.4 -12% Normal 70 18 Total thiamine 31.6 1.3 AD 73 20 10.1 0.8 -8% Normal 70 18 Thiamine 11.0 0.7 AD 73 20 3.7 0.4 +12% Normal 70 18 

TMP 

3.3 0.3 

AD 73 20 14.1 0.6 -21% 

Mastrogiacoma 1996 

Normal 70 18 

TDP 

Occipital 

cortex 

pmol/mg 

17.8 1.0 

NS: non-significant; TDP: thiamine diphosphate; TMP: thiamine monophosphate; SD: standard deviation a Percent of change: mean levels of thiamine derivative in the AD compared to controls. b AD with histologically significant lesions at autopsy. c AD without histologically significant lesions at autopsy.
84 

Riboflavin (Vitamin B2) Level Association Studies 

Study Descriptions. Two studies 106,107 reported cross-sectional data on riboflavin (B2) levels 

among AD, PD, and dementia subjects. One study compared blood levels of B2 in AD with 

control subjects, and the other compared plasma levels of B2 in PD with dementia subjects. 

Scileppi 1984 assessed blood levels of 12 vitamins among 55 AD subjects. The control group 

included a total of 58 normal, depressed, vascular and mixed dementia subjects. Coimbra 2003 

assessed plasma levels of B2 among 31 PD subjects compared with 10 dementia subjects without 

stroke. These studies were assessed to be of poor quality (C) and moderate applicability. 

Overall Effect. Scileppi 1984 reported no significant differences in the riboflavin levels between 

AD and the control groups. Coimbra 2003 found a mean plasma B2 level below normal among 

PD subjects, which was significantly lower than among subjects with dementia. Neither study 

adjusted for any confounders. 

Summary. Two poor quality studies assessed the cross-sectional levels of riboflavin among AD, 

PD, dementia, and other control groups. One study reported no significant difference between 

AD and control subjects. The second reported lower plasma levels among PD subjects with a 

significant difference between PD and dementia subjects. 

Table 25. Association of riboflavin (vitamin B2) levels with diagnosis of neurocognitive disorders 

Author Plasma Riboflavin Level (ng/mL) 

Year Population Mean Age 

(yr) 

N Mean SD Normal Range P Applicability Quality 

Scileppi AD 55 295 10 

1984 Non-AD nd 58 292 9 >110 NS dd C 

Coimbra PD 68 31 100.9 22.0 

2003 Dementia w/o 

Stroke 78 10 128.8 25.6 125-300 <.01 dd C 

SD: standard deviation; NS: non-significant 

Vitamin B6 Level Association Studies 

Study Descriptions. Ten studies examined the association of vitamin B6 serum levels with the 

diagnosis of dementia or cognitive impairment, and cognitive function, including three 

prospective longitudinal studies, one case control study, one retrospective cohort study, and five 

cross-sectional studies.18,105-111 Pyridoxal-5’-phosphate (PLP), an active coenzyme form of B6, 

was used to estimate B6 serum levels in all but two studies; one did not report the method for 

estimating B6111 and another study used a protozoological assay.105 The longitudinal studies 

recruited 313 to 1,092 participants, the case control study 80 subjects while the sample size for 

the other studies ranged from 30 to 127. Studies had narrow to broad applicability. Two of the 

longitudinal studies, the case control study and the retrospective cohort were of moderate quality 

(B) while the third longitudinal study and the five cross-sectional studies were of low quality (C). 

 One longitudinal study recruited participants with normal cognitive function and investigated 

whether low baseline levels for vitamin B6 may be a risk factor for cognitive decline after about 

3 years of follow-up (Table 26).112 Cognitive decline was defined as 7 year cognitive change 

with at least a 9-point drop of the total cognitive score (the sum of all subtest scores). Another 

longitudinal study also recruited participants with normal cognitive function and tried to 
85 

correlate cognitive function after almost 8 years of follow-up with the baseline levels of vitamin 

B6 (Table 26).96 Cognitive function in this study was assessed by MMSE score, as well as by 

tests on construction praxis, language, working and recall memory. In the third longitudinal 

study, subjects with normal cognitive function were followed for a median of 8 years and new 

cases of AD or dementia were recorded (Table 26).18 The case control study compared the 

number of subjects with low PLP among patients with AD with that among individuals with 

intact cognitive function.109 The retrospective cohort study correlated the number of lesions in 

autopsies of women with AD with B6 levels105 while the rest of cross-sectional studies compared 

the mean B6 serum levels between different groups of participants, one comparing patients with 

AD, persons cognitively impaired but not demented, and normal participants; another study 

compared patients with AD and patients with other dementias; another comparing patients with 

AD and normal individuals; and the other two comparing patients with PD to patients with 

dementia, or to normal subjects (Table 27). 

Overall Effect. Seshadri 2002, in the longitudinal study, reported that B6 serum levels were not 

correlated with the risk of AD or other dementias after adjusting for age, sex, and ApoE 

genotype; although specific results were not provided. Kado 2005 did not find any significant 

increase in the risk for cognitive decline for participants with very low vitamin B6 levels after 

adjusting for age, sex, education, baseline cognitive function, baseline physical function, and 

smoking. However, Tucker 2005, after adjusting for baseline cognitive measures, age, education, 

smoking, alcohol intake, BMI, diabetes, systolic blood pressure, time of second measure relative 

to folic acid fortification, time interval between the two cognitive measures, and serum 

creatinine, reported a significant correlation between higher levels of vitamin B6 at baseline and 

better performance in the figure copying test after 3 years of follow-up (β=0.38, P <0.05). No 

other significant association was described in the same study between vitamin B6 levels and the 

score of other cognitive tests. 

 None of the cross-sectional studies found any significant correlation between B6 levels and 

diagnosis of AD or number of AD lesions in brain autopsy, cognitive impairment, or dementia. 

In addition, two cross-sectional studies found no association between B6 level and diagnosis of 

PD, compared to either people with dementia or normal people. 

Interactions and Covariates. Generally, results were non-significant irrespective of the study 

design. Woitalla 2004 examined the association of B6 levels and diagnosis of PD in patients with 

different MTHFR genotypes (CC, CT, TT). No significant difference was reported when the 

three genotype groups were compared to each other or to the non-PD participants. There was no 

evidence across studies of differences in association with tests of different cognitive domains. 

Summary. Three prospective longitudinal studies, one case control study, one retrospective 

cohort, and five cross-sectional studies examined the potential correlation of B6 serum levels 

with the diagnosis of dementia or cognitive impairment, and cognitive function. The studies were 

generally of low quality and had narrow to broad applicability. Only one of the longitudinal 

studies described a significant correlation between higher levels of vitamin B6 at baseline and 

better performance in the figure copying test after 3 years of follow-up. However, a similar 

association was not found for other cognitive tests that were assessed in the same study. It is 

uncertain whether the improvement in performance in the figure copying test is clinically 

important. Additionally, no statistically significant correlations were reported between B6 levels 
86 

and AD or number of AD lesions in brain autopsy, cognitive impairment, PD, or dementia. There 

is very limited, low quality evidence to allow conclusion for any association between B6 levels 

and prevention or regression of cognitive function decline.
87

Table 26. Association of serum PLP level with diagnosis of AD, dementia, cognitive decline and cognitive function status in lon

B Vitamin Level (ng/mL) 

Author 

Year 

Baseline 

Population 

Mean Age 

(yr) N Follow-up Mean SD Normal Range Outcomes Result

<8.7 

Kado, 2005 Normal 74 370 7 yr 

≥8.7 

 nd Increased risk of cognitive decline a RR 1.2 (95%C

MMSE  β 0.15 d 

Construction praxis: 

spatial copying, sum of 

drawings  β 0.38 e 

Language: verbal 

fluency  β 0.56 d 

Working memory: 

backward digit span, 

longest span recalled  β -0.03 d 

Tucker, 2005 Normal 67 313 c Mean 1092 days 21.3 20.8 ≥4.9 

Recall memory: word 

lists, total of 3 trials  β 0.33 d 

Seshadri, 2002 Normal 76 1092 f Median 8 yr (Range 1-13) nd Coefficient of variation 16% Newly diagnosed AD; newly diagnosed dementia After adjusting for a

ApoE genotype, B6 not related to the ridementia or AD 

 Higher score indicates better cognitive function.  Lower score indicates better cognitive function. PLP, pyridoxal-5’-phosphate (active 

RR, Risk ratio; CI, confidence interval 

a Defined as 7 year cognitive change ≥ 9-point drop (worst quartile). b Adjusted for age, sex, education, baseline cognitive function, baseline physical function, and smoking; results non significant. c For MMSE, N=271-275; for construction praxis, N=280-284; for language, N=239-243; for working memory, N=236-240; and for recall md β adjusted for baseline cognitive measures, age, education, smoking, alcohol intake, BMI, diabetes, systolic blood pressure, time of se

folic acid fortification, time interval between the two cognitive measures, and serum creatinine. e β adjusted for baseline cognitive measures, age, education, smoking, alcohol intake, BMI, diabetes, systolic blood pressure, time of sefolic acid fortification, time interval between the two cognitive measures, and serum creatinine; figure copying score in participants with Pdecreased significantly compared to figure copying score in participants with PLP>21 ng/mL (-0.6 vs. +0.2, p<0.01). f Of the total population N=1092, 92% had measurements for B6; not reported how many of these patients with B6 measurements develo
88

Table 27. Association of serum PLP level with diagnosis of AD, cognitive impairment, dementia, and PD in retrospective co

cross-sectional studies 

B Vitamin Level (ng/mL) 

Author 

Year Population 

Mean Age (yr) N Mean SD Normal Range Correlation estim

AD 78 32 29.9 62.8 AD with VD 82 11 18.3 14.6 Normal 75 22 15.8 9.1 Miller, 2002 

Normal with VD 76 15 26.4 30.1 

 nd 

With significant number of AD lesions (postmortem autopsy) 15 78.8 46.7 r = 

−0.38 

Snowdon, 2000 b Without significant number of AD 

lesions (postmortem autopsy) 

91 

15 71.7 16.1 r = +0.03 

Participants in the bottom quartile of total cognitive score <8.7 nd Kado, 2005 Participants not in the bottom quartile of total cognitive score 

74 499 

≥8.7 nd 

nd RR 1.37 (95%CI 0.96-?) 

AD 34 2.42 

Ravaglia, 2000 Cognitive Impaired-not demented 10 2.94 e

Normal 

~10

0 13 2.00 

Lower 

reference 

value: 2.89 

nd 

AD nd 55 44.9 6.3 (SE) Scileppi, 1984 Normal and other dementias f nd 58 38.2 2.4 (SE) ≥105 nd 

Malaguarnera, AD 73 22 12.9 2.7 2004 g Normal 74 24 14.2 2.0 nd 

PD 68 31 6.25 1.5 Coimbra, 2003 Dementia 78 10 6.01 2.3 nd PD h 65 83 18.7 6.7 Woitalla, 2004 Normal 68 44 19.2 8.7 nd AD nd 55 44.9 6.3 (SE) Scileppi, 1984 Normal and other dementias nd 58 38.2 2.4 (SE) ≥105 nd 

PLP, pyridoxal-5’-phosphate (active coenzyme form of B6); VD, Vascular Disease; RR, Risk ratio; CI, confidence interval a OR for low PLP (<6.18 ng/mL): 12.3 (95%CI 1.8-84) based on logistic regression model adjusted for age, gender, RBC folate, plasma B

serum TSH, plasma homocysteine. 

b Retrospective cohort; vitamin B6 was assessed by a protozoological assay. c Adjusted for age, sex, education, baseline physical function, and smoking. Confidence interval does not agree with point estimate. Upp

1.07.
89 

d

 In age- and sex-adjusted analysis, there was significant trend for increasing risk of poor cognitive function (being in 

the bottom quartile of baseline total cognitive score) with decreasing B6 (P for trend 0.002). e

 Five additional subjects had vascular dementia and 1 PD (PLP levels not given for these patients). B6 deficiency 

was present in 85% of normal centenarians, 50% of cognitively impaired not-demented, and 64.7% of AD. Among 

patients with vascular dementia, 40% had B6 deficiency. 

f

 Normal and other dementias: normal (intellectually intact, n=10), multi-infarct dementia (n=28), other dementias 

(n=8), and depression (n=12). 

g

 22 additional patients with vascular dementia were not included in the analysis. 

h

 Total PD patients 83; PD patients with CC allele: 38, PD patients with CT allele: 12, PD patients with TT allele: 33.

Cobalamin (Vitamin B12) Level Association Studies 

Study Descriptions. Seven longitudinal studies examined the potential association of serum B12 

levels with the risk for developing dementia, AD, or cognitive decline (Table 28).18,25,96,112-115

Two of the longitudinal studies recruited participants with normal cognitive function and tried to 

correlate cognitive function after 3 and 8 years of follow-up to the baseline levels of vitamin 

B12.96,114 Cognitive function in these two studies was assessed by MMSE score, as well as by 

tests on construction praxis, language, working and recall memory, and visual reproduction. 

Sample size ranged between 234 and 1092 among the studies. Six studies included cognitively 

intact subjects while the seventh also recruited patients with AD. Follow-up ranged between 20 

months and 8 years. Studies were generally of moderate quality (5 B, 2 C) and broad 

applicability. 

 Four cross-sectional studies assessed the potential association between B12 serum levels and 

cognitive function (Table 29).83,116-118 Sample size ranged from 127 to 680. One study included 

patients with AD and frontotemporal dementia, another study had patients with PD and normal 

individuals while two studies recruited only subjects with AD. All studies implemented MMSE 

to assess cognitive function. In addition one study used ADAS test while another used Mattis’ 

DRS. Studies were of low to moderate quality (2 B, 2 C) and narrow to broad applicability. 

 There were 22 additional studies that compared the B12 serum levels between different 

groups of participants.99,106,107,111,119-136 Two of the longitudinal studies also compared mean B12 

levels with AD diagnosis and cognitive function at baseline.25,113 Five studies estimated the odds 

ratio for AD or cognitive impairment at certain B12 serum levels (Table 30).120,121,123,127,130 Nine 

studies compared the percentage of participants with low serum B12 level among different 

groups including subjects with dementia, cognitive impairment, AD, vascular dementia, and 

cognitively intact individuals (Table 31).25,119,121,122,124,125,129,133,134 Definitions of low B12 level 

varied among studies, ranging from ≤139 mg/mL to <340.1 mg/mL. In addition, 19 studies 

compared the mean B12 serum levels between different groups of participants, such as subjects 

with dementia, cognitive impairment, AD, senile and vascular dementia, PD, and cognitively 

intact individuals (Table 32).99,106,107,111,113,120,122-132,134,135 Sample size ranged from 41 to 939. All 

studies measured serum B12 levels except for one study that reported also CSF B12 levels.124

Studies were of low to moderate quality (1 A, 7 B, 14 C) and narrow to broad applicability. 

Overall Effect. None of the longitudinal studies showed any significant correlation between 

serum B12 levels and the risk for developing AD or dementia. However, Tucker 2005, after 

adjusting for baseline cognitive measures, age, education, smoking, alcohol intake, BMI, 

diabetes, systolic blood pressure, time of second measure relative to folic acid fortification, time 

interval between the two cognitive measures, and serum creatinine, reported a significant 

correlation between higher levels of vitamin B12 at baseline and better performance in the figure 
90 

copying test after 3 years of follow-up (β=0.56, P <0.05). Similarly, Elias 2005, after adjusting 

for age, education, and gender as well as for Framingham stroke risk profile score, creatinine, 

alcohol consumption, coffee consumption, total cholesterol, BMI, and ApoE genotype described 

a significant correlation between higher levels of vitamin B12 at baseline and better performance 

in the global composite score for cognitive function after almost 8 years of follow-up (β=0.002, 

P <0.05). This study also reported significant correlation for immediate and delayed recall in the 

visual reproduction test (β=0.04, P<0.02 and β=0.04, P<0.03 respectively). 

 Among the other studies that evaluated cognitive function, no significant correlation was 

found between B12 serum levels and cognitive function test scores for any of the populations 

included. Among the studies that estimated OR, only Argyriadou 2001 found that the odds for 

low B12 serum level is two-fold higher in subjects with MMSE score low enough to show 

cognitive impairment than in cognitively intact individuals (P=0.03). The cutoff level for low 

B12 in this paper was <145 mg/mL. There were two more studies, which did not estimate an OR, 

but reported that significantly more subjects with AD or cognitively impaired presented with low 

serum B12 levels. Tripathi 2001 compared patients with AD and low B12 levels (<187 mg/mL) 

and subjects with other types of dementia (P<0.05) while Shahar 2001 compared cognitively 

impaired subjects presenting with lower B12 levels (<203 mg/mL) and cognitively impaired 

subjects with higher B12 levels (one group with B12 levels 150 to 250 mg/mL and another with 

greater than 250 mg/mL) (P=0.04 after adjusting for age). 

 Clarke 1998 compared mean serum B12 levels between patients with AD and cognitively 

intact participants and found no significant difference. However, when the same study was 

restricted only to the population with a histological diagnosis of AD, it found that significantly 

lower serum B12 levels were measured compared to the normal population (P<0.05). A 

subgroup of the participants in the same study, including 51 subjects with histological diagnosis 

of AD and 65 normal participants, was evaluated in a later publication by Refsum 2003. Serum 

holotranscobalamin levels, an active part of total serum B12, were measured and were found to 

be significantly lower in patients with AD than in controls (P<0.001). 

 Postiglione 2001 also found significantly lower B12 levels in patients with AD compared to 

normal individuals but the difference was not significant when the analysis was adjusted for age, 

serum creatinine, and duration of AD. In addition Religa 2003 reported significantly lower serum 

B12 levels in the AD group compared to cognitively intact participants (P<0.05). In the same 

study, no significant difference was reported when subjects with mild cognitive impairment were 

compared with the normal population. Tripathi 2001 also compared subjects with AD and 

patients with other dementias and found that the AD population presented with significantly 

lower B12 levels. In contrast Regland 1988 found that mean vitamin B12 levels for AD and 

cognitively intact groups were normal while the senile dementia group had a significantly lower 

B12 level (P=0.0002). None of the other studies including populations with AD or cognitive 

impairment supported any significant differences for B12 levels. Studies with subjects presenting 

with PD and vascular dementia did not report any significant results. 

Interactions and Covariates. Prospective longitudinal studies reached statistical significance less 

often than cross-sectional studies. When they reported significant associations, both longitudinal 

and cross-sectional studies usually found that better cognitive function was related to higher 

vitamin B12 levels. Assantachai 1997 found that patients with AD and ApoE ε4 genotype had 

significantly lower B12 levels than patients with vascular dementia and ApoE ε4 genotype, while 

AD patients with other genotypes had similar B12 levels as those with vascular dementia. 
91 

 Woitalla 2004 examined the correlation of B12 levels and diagnosis of PD in patients with 

different MTHFR C677T genotypes (CC, CT, TT). No significant difference was reported when 

the three genotype groups were compared to each other or to the non-PD participants. McCaddon 

2004 found that holotranscobalamin was significantly higher in CC genotypes than the 

heterozygous CG genotype (P=0.04). Postiglione 2001 also found non-significant differences in 

B12 levels when they analyzed subcategories of AD patients or controls who were homozygous 

for MTHFR C677T or non-homozygous. 

 Postiglione 2001 also reported a statistically significant correlation between duration of 

disease in months and B12 (r = –0.460, P<0.05), supporting a decrease in B12 vitamin levels 

with longer AD duration. Anello 2004 reported that B12 levels were not influenced by other 

covariates such as the severity of dementia or age of onset of the disease. Refsum 2003 showed 

that low holotranscobalamin was associated with AD at high total homocysteine concentrations 

(OR 9.45), but not at low homocysteine concentrations. 

 There was no evidence across studies of differences in association with tests of different 

cognitive domains. 

Summary. Thirty-three studies of low to moderate quality and narrow to broad applicability 

investigated a potential association between serum or CSF vitamin B12 levels and cognitive 

function, or diagnosis of several types of dementia and cognitive impairment. Most of the studies 

focused on AD. The threshold values to define low B12 levels varied across studies. Based on 

the very few longitudinal studies, vitamin B12 levels did not affect the risk for developing AD or 

dementia. However, one of the longitudinal studies reported a significant correlation between 

higher levels of vitamin B12 at baseline among cognitively intact subjects and better 

performance in the figure copying test after 3 years of follow-up. Another longitudinal study also 

described a similar correlation for the global composite score for cognitive function and the 

immediate and delayed recall in the visual reproduction test after almost 8 years of follow-up. 

However, the clinical importance of these results is unclear. The existing evidence from other 

studies, which implemented a cognitive function assessment instrument, did not support any 

correlation between vitamin B12 levels and cognitive function. Among cross-sectional studies, 

there was a trend for vitamin B12 levels to be lower in patients with AD or other types of 

dementia, which in certain studies reached statistical significance. However, this trend was not 

consistent. An inverse correlation between vitamin B12 levels and duration of AD was reported 

by one study. Besides that evidence for patients with AD or cognitive impairment, there was 

very limited evidence for populations with PD, and vascular dementia. Potential factors such as 

genetic mutations, or disease severity that may affect vitamin B12 levels were analyzed by few 

studies without a consistent effect. Considering also that most of the studies were cross-sectional, 

no causal relation between B12 vitamin and the developing or progression of dementia can be 

established. 
92

Table 28. Association of serum vitamin B12 levels with diagnosis of AD, dementia, or cognitive decline in longitudinal studies 

Author 

Year 

Baseline 

Population 

Baseline 

Mean Age (yr) N Follow-up B Vitamin Level Threshold (pg/mL) Outcomes Results 

Newly diagnosed 

dementia HR 0.8 (95% CI 0

Ravaglia, 2005 Normal 73.6 937 Mean 3.8 yr <340.1 Newly diagnosed AD HR 0.7 (95%CI 0

Global composite score  β 0.002 b Visual reproductionsimmediate recall  β 0.036 b 

Elias, 2005 Normal ≥60 705 Mean 7.6 yr Mean 447 Visual reproductiondelayed recall  β 0.041 b 

Newly diagnosed AD Unadj: RR 1.7 (95% 

Adj c: RR 1.6 (95% 

Wang, 2001 MMSE  ≤ 26 

MMSE  > 26 

75-

101 370 3 yr 

≤203 

>203 Newly diagnosed dementia Unadj: RR 1.4 (95% 

Adj c: RR 1.3 (95% 

<294.1 Kado, 2005 Normal 74 370 7 yr ≥294.1 Increased risk of cognitive decline d RR 1.4 (95%CI 0

MMSE  β -0.16 g 

Construction praxis: spatial 

copying, sum of drawings  β 0.56 g 

Language: verbal fluency  β 0.06 g 

Working memory: backward 

digit span, longest span 

recalled  β 0.18 g 

Tucker, 2005 Normal 67 315 f Mean 1092 days Range: 122-1449 

Recall memory: word lists, 

total of 3 trials  β -0.20 g 

Seshadri, 2002 Normal 76 1092 Median 8 yr nd Newly diagnosed AD; newly diagnosed dementia 

After adjusting foand ApoE genotylevels were not inrelated to the risk or AD 
93

Table 28. Association of serum vitamin B12 levels with diagnosis of AD, dementia, or cognitive decline in longitudinal studies (

Author 

Year 

Baseline 

Population 

Baseline 

Mean Age (yr) N Follow-up B Vitamin Level Threshold (pg/mL) Outcomes Results 

AD nd 76 

Bowirrat, 2002 Normal nd 158 

Mean 20 

mo nd Newly diagnosed AD 

Subjects in the lotertile did not havrisk to develop AD adjustment for yeand gender 

 Higher score indicates better cognitive function. yr, years; mo, months; unadj, unadjusted; adj, adjusted; RR, Risk ratio; CI, confidence 

MMSE, Mini-Mental State Examination score 

a Adjusted for age, sex, education; ApoE genotype; stroke; serum concentrations of creatinine, folate, Hcy, BMI, diabetes, cardiovascula

hypertension; results non significant. 

b Adjusted for age, education, and gender (not clear if it is also adjusted for Framingham stoke risk profile score, creatinine, alcohol cons

consumption, total cholesterol, BMI, and ApoE genotype). 

c Adjusted for age sex and education; both unadjusted and adjusted RR were non significant. d Defined as 7 year cognitive change ≥ 9-point drop (worst quartile). e Adjusted for age, sex, education, baseline cognitive function, baseline physical function, and smoking; results non significant. f For MMSE, N=271-275; for construction praxis, N=280-284; for language, N=239-243; for working memory, N=236-240; and for recall mg Adjusted for baseline cognitive measures, age, education, smoking, alcohol intake, BMI, diabetes, systolic blood pressure, time of seco

folic acid fortification, time interval between the two cognitive measures, and serum creatinine.
94

Table 29. Association of serum vitamin B12 levels with cognitive function in cross-sectional studies 

B Vitamin Level (pg/mL) Results 

Author 

Year 

Population 

Mean Age (yr) N Mean SD Normal Range P Test / Subtest Mean Cognitive Score r 

AD 79 37 ≤ 200 14.7 Whyte, 2002 AD 75 643 ≥ 201 nd ≥ 201 nd MMSE  16.9 nd PD 75 83 Clarke, 2003 Normal nd 44 nd nd nd nd MMSE  nd Unadj: - 

Adj: -0.

Engelborghs, AD 79 152 383 258 2004 FTD 69 28 317 120 193-982 nd MMSE  nd Stuerenburg, 2004 AD 72 241 371 216 nd nd MMSE  nd 

PD 75 83 Clarke, 2003 Normal nd 44 nd nd nd nd ADAS cognitive  nd Unadj: - 

Adj: 0.0

AD 79 37 ≤ 200 105.4 Whyte, 2002 AD 75 643 ≥ 201 nd ≥ 201 nd Mattis DRS  110.8 nd 

 Higher score indicates better cognitive function.  Lower score indicates better cognitive function. FTD, Fronto Temporal Dementia; M

examination; ADAS cognitive, Alzheimer's Disease Assessment Scale-Cognitive; Mattis DRS, Mattis’ Dementia Rating Scale 

a Adjusted for age. 
95

Table 30. Studies reporting odds ratio (OR) or risk ratio (RR) for diagnosis of AD or cognitive impairment at threshold vitamin B

Author 

Year Population 

Mean Age 

(yr) B Vitamin Level (pg/mL) N OR /RR 95% C

276 - 352 0.7 a 0.3, 1.9 Mizrahi, 2004 AD Normal 74 75 <276 230 1.3 a 0.5, 3.4 

Cognitively impairedNormal 76 317 - 411 81 0.8 b 0.3, 2 ADNormal 

79 76 317 - 411 74 0.6 b 0.2, 1.7 

Cognitively impairedNormal 76 <317 81 1.0 b 0.4, 2.4 

Quadri, 2004 

ADNormal 

79 76 <317 74 0.8 b 0.3, 2 

Anello, 2004 AD Normal 71 70 nd 361 1.0 0.99, 1.

271- 379 1.3 a 1.7 d 0.8-2 AD 1-3 

Normal 73 <271 272 1.4 a 1.4 d 0.9-2.2 0.8-2.5 

271- 379 2.1 a 5.6 d 1.2-3.6 2.6-11.

Clarke, 1998 Refsum 2003 

AD (histological diagnosis) Normal 

78 73 <271 184 1.8 a 4.3 d 1.0-3.2 2.1-8.8 

Argyriadou, 2001 

MMSE  ≤ 24 

MMSE  > 24 ≥65 <145 536 2.0 e 1.1, 4.0 

<294.1 

Kado, 2005 

Participants in the bottom quartile of total cognitive score Participants not in the bottom quartile of total cognitive score 

74 ≥294.1 499 1.2 f 0.8-1.7 

 Higher score indicates better cognitive function. MMSE, mini-mental status examination. a Adjusted for age and sex. b Adjusted for age, sex, education and creatinine. c Results were remained NS also with a multivariate analysis adjusted for 

MTHFR, ApoE ε4, and TCN1 genotypes, and homocysteine level (and other 

B vitamin); B12 levels were not influenced by the sof onset of the disease. 

d Adjusted for age, sex, smoking, social class, and e Adjusted for age, intake site, and anemia (and otf Adjusted for age, sex, education, baseline physic
96

Table 31. Studies reporting prevalence of subjects with threshold serum vitamin B12 levels among those with dementia diagno

Author 

Year Population 

Mean Age (yr) N B Vitamin Level (pg/mL) Normal Range % Subjects 

17.3 ≤203 nd 14.2 52.6 Wang, 2001 MMSE  ≤ 26 MMSE  > 26 75-101 173 197 ≤339 nd 42.6 

AD 71 465 4 Cacabelos, 2004 Vascular dementia 70 474 <150 ≥150 3 AD 68 74 5 Postiglione, 2001 Normal nd 74 <179 179-1132 0 AD ≤43 0 Mild cognitive impairment ≤32 6.3 Vascular dementia ≤14 7.7 Gottfries, 2001 a

Subjective memory complaints 

70 

≤12 

<203 ≥203 

8.3 

≥145 37.9 MMSE  ≤ 24 <145 55.4 ≥145 62.1 MMSE > 24 

≥65 245 

<145 

≥145 

44.6 

≥145 34.8 MMSE  ≤ 24 (men) <145 62.5 ≥145 65.2 MMSE  > 24 (men) 

≥65 245 

<145 

≥145 

37.5 

≥145 40.5 MMSE  ≤ 24 (women) <145 50.0 ≥145 59.5 

Argyriadou, 2001 

MMSE  > 24 (women) 

≥65 291 

<145 

≥145 

50.0 

AD 83 52 3.8 

Joosten, 1997 Normal (hospitalized) 81 50 10.0 

Normal (non hospitalized) 79 49 

<139 140-550 

6.1 

AD 62 38 39.5 Tripathi, 2001 Other dementia b 60 62 <187 187-1057 12.9 

<203 46.9 

Shahar, 2001 Cognitively impaired 78 238 150 - 250 36.4 

>250 

>338.8 

35.7 

 Higher score indicates better cognitive function. MMSE, mini-mental status examination; unadj, unadjusted; adj, adjusted 
97

a 101 participants in total cohort (43+32+14+12); for plasma B12, N=99. b Other dementia included mixed, diffuse Lewy body disease, infections, nutritional, head injury, systemic, extra-pyramidal, etc. c Adjusted for age.Table 32. Association of serum and CSF vitamin B12 levels with diagnoses of dementias in cross-sectional studies 

B Vitamin Level (pg/mL) 

Author 

Year Population 

Mean Age 

(yr) N Mean SD Normal Range 

AD 74 75 323 136 Mizrahi, 2004 Normal 75 155 351 175 ≥169 AD 79 74 381 111 

Quadri, 2004 Cognitively impaired 81 373 117 

Control 76 55 377 99 nd 

Cognitively impaired 51 460 488 Assantachai, 1997 Normal 69 108 408 184 nd AD 71 465 488 328 Cacabelos, 2004 Vascular dementia 70 474 521 505 ≥150 AD 71 180 377 221 Anello, 2004 Normal 70 181 283 211 nd AD 164 236 112 Normal 73 108 253 100 nd AD (histological diagnosis) 78 76 215 79 

Clarke, 1998 Refsum 2003 

Normal 73 108 253 100 nd 

AD 68 74 689 301 Postiglione, 2001 Normal nd 74 701 234 179-1132 Una

Ad

AD 59 35 432 179 

Regland, 1988 Senile dementia 75 56 333 214 

Control 72 54 454 249 

nd .

AD 74 99 317 140 Normal 71 100 414 241 Mild cognitive impairment 98 386 159 Religa, 2003 

Normal 

71 

100 414 241 

157-1059 

AD nd 76 nd nd Bowirrat, 2002 Normal nd 158 nd nd nd 
98

Table 32. Association of serum and CSF vitamin B12 levels with diagnoses of dementias in cross-sectional studies (Continued

B Vitamin Level (pg/mL) 

Author 

Year Population 

Mean Age (yr) N Mean SD Normal Range 

PD 65 83 371 218 Woitalla, 2004 Normal 58 44 418 233 nd AD 333 nd McCaddon, 2004 Normal 79 121 c 342 nd nd AD ≤43 356 177 Mild cognitive impairment ≤32 296 127 Vascular dementia ≤14 272 143 Subjective memory complaints 

70 

≤12 330 154 

203 - 949 

AD ≤43 13.9 13.6 Mild cognitive impairment ≤32 11.3 7.9 Vascular dementia ≤14 10.8 8.5 

Gottfries, 2001 e

Subjective memory complaints 

70 

≤12 14.4 8.7 

CSF: nd 

Dementia f 68 323 136 Nilsson, 1996 Normal 75 163 351 175 149 - 881 AD 83 52 284 nd 

Joosten, 1997 Normal (hospitalized) 81 50 281 nd 

Normal (non hospitalized) 79 49 284 nd 

140-550 

AD nd 55 290 31 (SE) Scileppi, 1984 Normal and other dementias g nd 58 533 25 (SE) ≥105 AD 62 38 263 168 Tripathi, 2001 Other dementia h 60 62 289 139 187-1057 PD 68 31 356 261 Coimbra, 2003 Dementia w/o Stroke 78 10 441 323 nd MMSE  24-25 46 233 nd 

Ravaglia, 2003 MMSE  26-28 259 240 nd 

MMSE  > 28 

~100 

345 237 nd 

≥201 

 Higher score indicates better cognitive function. CSF, Cerebrospinal fluid; MMSE, mini-mental status examination; unadj, unadjusted; a Patients with AD and ApoE 2/4 (n=4 or 6) had significantly lower B12 level (364±141 pg/mL) than patients with vascular dementia and A

pg/mL; P < 0.04); AD patients with other genotypes had similar B12 levels as their counterparts with vascular dementia.
99 

b

 Adjusted for age, serum creatinine, and duration of AD; also NS differences in B12 levels by subcategories 

of cases or controls who were homozygous for MTHFR C677T or non-homozygous; statistically significant 

correlation between duration of disease (months) and B12 (r = –0.460, P < 0.05). c

 Initially AD:70 and Normal: 74 but 23 subjects were excluded from the analysis because they received B12 

supplementation; unclear how many of the excluded subjects were in the AD or in the Normal group. d

 Results also for holotranscobalamin levels were NS. 

e

 101 participants in total cohort (43+32+14+12); for plasma B12, N=99. 

f

 AD, frontotemporal dementia and other dementia including alcohol and brain tumor dementia. g

 Normal (intellectually intact, n=10), multi-infarct dementia (n=28), other dementias (n=8), and depression 

(n=12). 

h

 Other dementia included mixed, diffuse Lewy body disease, infections, nutritional, head injury, systemic, 

extra-pyramidal, etc.

Folate Level Association Studies 

Study Descriptions. A total of 34 studies examined the role of folate vitamin levels with the 

diagnoses of age related neurocognitive disorder or with cognitive function. Twenty-three studies 

examined the mean folate level with cognitive function or PD,83,99,105-107,109,111,113,116,120,122-125,127-

132,137-139 10 examined the prevalence of folate deficiency in normal and cognitively impaired or 

demented participants,25,114,119,121,122,124,125,129,140,141 and 15 assessed the risk of AD, dementia, and 

cognitive impairment with folate levels.18,25,96,105,112-115,120,121,123,127,130,140,142 Ten of the studies 

were longitudinal, examining the association between folate levels and future cognitive function; 

the remainders were case-control or cross-sectional with single time-point analyses (Table 33). 

The folate levels were assessed in the RBC, plasma, serum, CSF, and blood. The sample sizes of 

the studies ranged from 30 to 1,100. The majority of the studies were graded moderate to poor 

quality (1 A, 15 B, 18 C). Fifteen studies had broad, 17 moderate, and 2 narrow applicability. 

Overall Effect. All studies reported lower mean folate levels or higher prevalence of folate 

deficiency among subjects with AD, and cognitive impairment. Among studies that assessed the 

association between folate levels and cognitive function, four longitudinal studies and one casecontrol study reported a statistically significant association between lowest quantile of folate 

level and cognitive decline after adjusting for possible confounders. One other case-control study 

reported a significant inverse association of folate with cognitive function. Two studies reported 

folate levels within normal limits among PD subjects. 

 Fewer than one-third of the 23 studies that examined the mean folate levels and cognitive 

function reported significantly lower mean folate levels in AD compared with normal subjects 

(Table 33). Only two studies – Postiglione 2001 and Bowirrat 2002 – adjusted mean folate levels 

for possible confounders; they reported no significant differences in mean folate levels between 

AD and normal subjects. 

 All studies that examined the prevalence of folate deficiency compared subjects with AD or 

cognitively impairment with other types of dementia or normal subjects (Table 34). The range of 

prevalence of folate deficiency was between 0 and 67 percent. Across all studies, the prevalence 

of folate deficiency was higher among AD than controls. Only two studies, Joosten 1997 and 

Wang 2001 reported statistically significant prevalence of folate deficiency among AD subjects, 

and those with MMSE mean score ≤26, respectively. 

 Among 10 studies that examined the longitudinal decline of cognitive function (Table 35), 

Ravaglia 2005, Kado 2005, Tucker 2005, Maxwell 2002, and Clarke 1998 compared the lowest 

versus the highest quantile of folate. After adjusting for possible confounders, Ravaglia 2005, 

Kado 2005, and Tucker 2005 found an increased risk of cognitive function decline among those 
100 

in the lowest quantile levels of folate. Tucker 2005 found independent effects of lowest folate 

level among men with mild cognitive impairment with longitudinal (mean of 3 year) and large 

decline in the score of constructional praxis (spatial copying). Maxwell 2002 examined the risk 

of adverse health outcomes including cognitive decline with association to the quartiles of folate 

during 5-year follow-up. This study noted that subjects with lowest folate levels were at greater 

risk for significant cognitive decline independent of possible confounders. In contrast, Seshadri 

2002, Elias 2005 and four other longitudinal studies found no association between folate level 

and future cognitive function. Three case-control and one cross-sectional studies assessed the 

odds of AD in relation to high versus the low levels of folate, using a single time point analyses 

(Table 36). Of note, Quadri 2004 reported a consistently significant association of cognitive 

impairment with the lowest tertile of folate. 

 Snowdon 2000, a case-control study described a significant negative age-adjusted correlation 

of folate levels with severity of cerebral cortex atrophy among all AD subjects, as well as a 

subset of AD subjects with histologically significant cerebral cortex lesions at autopsy. The 

regression analysis adjusted for age and histological severity of AD found a 4.4 ng/mL decrease 

in serum folate was associated with a 1-point decrease for the MMSE score indicating a 

significant inverse association of folate with cognitive function. 

 Two studies reported folate levels in PD subjects (Table 33). Woitalla 2004 compared the 

mean folate level in PD with normal subjects. This study subdivided PD and normal subjects 

according to their methylene tetrahydrofolate reductase (MTHFR) genotypes CC, CT, TT. The 

folate levels did not differ between PD and normal subjects, but was significantly higher in the 

CT allele subgroup of PD compared with normal subjects. Coimbra 2003 reported folate levels 

within the normal range that did not differ between PD and dementia subjects. 

Interactions and Covariates. About one-third of the studies reported associations of folate levels 

with cognitive function decline adjusted for possible confounders. Four longitudinal studies that 

adjusted for all possible confounders reported independent and statistically significant 

association between folate level and cognitive function. Across the studies, there was an 

association between folate level and global cognitive function. Only one study96 reported 

significant effect on one other cognitive domain. 

Summary. There are 34 studies of moderate to poor quality that have examined the role of folate 

vitamin levels with the diagnoses of age related neurocognitive disorder or with cognitive 

function. Overall, the studies reported lower mean folate levels or higher prevalence of folate 

deficiency among AD and cognitive impaired subjects. One-third of the studies adjusted for 

possible confounders. Of note, four of the 10 longitudinal studies reported consistent and 

statistically significant association between folate level and cognitive function score. Two casecontrol studies reported greater risk of cognitive function decline with lower folate levels among 

AD subjects. Two studies reported mean folate levels within normal limits among PD subjects. 
101 

Table 33. Association of mean folate levels with diagnosis of age-related neurodegenerative disease 

 Folate Level (ng/mL) 

Author 

Year Population 

Mean Age 

(yr) 

N Tissue Mean SD / 

range 

Normal 

Range P 

Applicability 

Quality 

Mizrahi AD ~80 75 1.9 1.4 NS 

2004 Normal ~77 155 Plasma 2.1 1.1 >1.6 ddd A 

AD 79 74 6.0 2.5 .04 

Cognitive 

impaired 76 81 6.2 2.6 .04 Quadri 

2004 

Normal 76 55 

Serum

7.5 2.6 

nd ddd B 

Cognitive 

impaired Assantachai 69 44 416 123 NS 

1997 Normal 69 103 

RBC 

399 143 

nd ddd B 

AD 71 465 6.1 2.8 NS Cacabelos 

2004 Vascular 

dementia 70 474 Blood 6.3 3.1 >3.0 dd B 

Anello AD 71 180 6.3 2.5 .09 

2004 Normal 70 181 Plasma 6.9 2.6 nd dd B 

AD (clinical 

diagnosis) 73 164 7.8 4.7 <.001 

AD (histological 

diagnosis) 77 76 6.7 4.2 <.001 

Normal 73 108 

Serum 

10.1 4.4 

nd 

AD (clinical 

diagnosis) 73 164 382 197 <.05 

AD (histological 

diagnosis) 77 76 325 170 <.001 

Clarke 

1998 

Normal 73 108 

RBC 

437 180 

nd 

dd B 

Mixed 

Dementia 75 98 3.2 3.1 NS Clarke 

2003 Cognitive 

impaired 75 51 

Plasma

3.8 3.1 

0.75-

13.5 dd B 

AD 68 74 2.5 

3.9 a 0.9 

1.5 

<.001 

NS a Postiglione 

2001 Normal 68 74 

Plasma 3.8 

3.4 a 1.4 

1.6 

3.1-12.4 dd B 

Miller AD 79 32 461 159 

2002 Normal 75 22 RBC 496 212 >160 NS dd B 

Snowdon AD lesions 91 15 8.8 10.2 

2000 AD no lesions 91 15 Serum 11.9 10.5 4.8-23.8 nd d B 

AD 74 99 8.5 3.4 NS 

Cognitive 

impaired 71 98 10.9 3.9 NS Religa 

2003 

Normal 71 100 

Serum 

7.6 5.4 

5.3-14.4 ddd C 

AD ≥60 76 nd nd NS b Bowirrat 

2002 Normal ≥60 158 Plasma nd nd nd ddd C 

PD 65 83 6.4 3.3 

CT allele 38 7.5 3.9 

TT allele 12 5.5 2.8 

CC allele 33 5.4 2.1 

Woitalla 

2004 

Normal 58 44 

Serum 

6.5 2.9 

nd <.02 c ddd C 

Continued 
102 

Table 33. Association of mean folate levels with diagnosis of age-related neurodegenerative disease 

(Continued) 

 Folate Level (ng/mL) 

Author 

Year Population 

Mean Age 

(yr) 

N Tissue Mean SD / 

range 

Normal 

Range P 

Applicability 

Quality 

AD 75 47 84.2 75.0 

AD with CVD 76 9 72.8 89.0 

Cognitive 

impaired 78 8 279 115 

Nagga 

2003 

Normal 75 101 

Serum 

nd nd 

33-210 <.05 d ddd C 

AD 70 ≤43 5.3 1.9 

Mild cognitive 

impaired 70 ≤32 6.2 3.0 

Vascular 

dementia 70 ≤14 5.0 2.0 

Subjective 

memory 

complaints 

70 ≤12 

Plasma 

5.6 2.3 

2.6-

17.2 f NS 

AD 70 ≤43 105 35 

Mild cognitive 

impaired 70 ≤32 112 40 

Vascular 

dementia 70 ≤14 118 64 

Gottfries 

2001 e

Subjective 

memory 

complaints 

70 ≤12 

Blood 

125 38 

61.8-

167 g NS 

ddd C 

MMSE  24-25 79 46 11.4 10.0, 13.0 

MMSE  26-28 73 259 11.3 10.7, 11.9 Ravaglia 

2003 

MMSE  > 28 72 345 

Serum 

11.6 11.1, 12.2 

2.5 NS dd C 

Men with 

dementia 84 20 4.1 nd NS 

Men with intact 

cognition 84 83 4.8 nd 

Women with 

dementia 85 66 3.6 nd <.005 

Nilsson 

2003 

Women with 

intact cognition 85 173 

nd

4.6 nd 

nd dd C 

Nilsson AD 75 68 57.4 58.3 <.05 

1996 Normal 75 163 Blood 68.8 68.8 55-221 g dd C 

AD 79 152 246 198 Engelborghs 

2004 Mixed 

dementia 69 28 RBC 277 195 93-641 NS dd C 

AD 82 52 3.5 1.3, 9.7 NS 

Non-AD h 81 50 4.0 1.5, 10.9 NS Joosten 

1997 Normal 79 49 

Serum 

3.8 1.8, 8.2 

2.4-7.2 dd C 

AD nd 55 11.7 1.5 NS 

Scileppi 

1984 

Normal and 

other 

dementia j

nd 58 Blood 10.7 1.0 >5.0 dd C 

AD 76 30 5.4 2.2 NS 

Normal 73 28 5.8 2.1 nd 

AD 76 30 8.3 1.8 <.001 

Serot 

2001 

Normal 73 36 

CSF 

10.0 2.0 nd 

dd C 

PD 68 31 5.6 4.0 NS Coimbra 

2003 Dementia w/o 

Stroke 78 10 Plasma 4.3 2.8 2-12 dd C 
103 

 Higher score indicates better cognitive function. MMSE: Mini-Mental State Exam; nd: not documented; NS: nonsignificant. 

a

 Adjusted for age, serum creatinine, and duration of AD. 

b

 Adjusted for age. 

c

 PD patients with CT allele had significantly higher folic acid levels compared with others in the post hoc analysis. d

 AD and AD with CVD had lower levels of blood folate vs cognitively impaired. 

e

 Total cohort =101 (43+32+14+12). However, plasma folate had N=98 and blood folate had N=74. 

f

 Plasma folate. 

g

 Blood folate. 

h

 Hospitalized. 

j

 Normal (intellectually intact, n=10), multi-infarct dementia (n=28), other dementias (n=8), and depression (n=12).

Table 34. Prevalence of folate deficiency among subjects with dementia, cognitive impairment, and normal 

cognition 

Author 

Year 

Population 

Mean Age (yr) 

N Tissue Folate Level 

(ng/mL) 

Normal 

range 

% Deficient 

P 

Applicability 

Quality 

Elias 

2005 Normal 60-

82 705 Plasma <3.1 nd 12.1 ddd B 

MMSE  ≤ 26 ≤4.4 22.1 

MMSE  > 26 

54 

≤4.4 

>4.4 

8.2 

<.01 

MMSE  ≤ 26 ≤5.3 35.5 

Wang 

2001 

MMSE  > 26 

75-

101 

105 

Serum 

≤5.3 

>5.3 

22.4 

<.01 

ddd B 

Cacabelos AD 71 465 5 

2004 Vascular dementia 70 474 Blood <3.0 >3.0 6 NS dd B 

61 <3.2 36.1 

61 3.2-4.5 23.0 

59 4.6-5.9 30.5 

Stewart 

2002 Cognitive impaired 65 

58 

Serum 

>5.9 

nd 

22.4 

NS dd B 

<2.2-5.3 33.3 AD a 49 >6.2-15.9 20.9 

<2.2-5.3 38.1 Dementia a 66 >6.2-15.9 24.3 

<2.2-5.3 43.5 

Maxwell 

2002 

Cognitive impaired b

80 

87 

Serum 

>6.2-15.9 

nd 

29.7 

nd dd B 

Postiglione AD 74 20 

2001 Normal 68 74 Plasma <3.1 3.1-12.4 0 nd dd B 

≥1.8 39.5 Cognitive impaired (all) 213 <1.8 46.7 

≥1.8 60.3 Normal (all) 315 <1.8 

≥1.8 

53.3 

≥1.8 37.7 Cognitive impaired men 92 <1.8 33.3 

≥1.8 62.3 Normal men 153 <1.8 

≥1.8 

66.7 

≥1.8 41.1 Cognitive impaired women 121 <1.8 55.6 

≥1.8 58.9 

Argyriadou 

2001 

Normal women 

65-

85 

170 

nd 

<1.8 

≥1.8 

44.4 

NS ddd C 

Continued 
104 

Table 34. Prevalence of folate deficiency among subjects with dementia, cognitive impairment, and normal 

cognition (Continued) 

Author 

Year 

Population 

Mean Age (yr) 

N Tissue Folate Level 

(ng/mL) 

Normal 

range 

% Deficient 

P 

Applicability 

Quality 

AD 43 0 

Cognitive impaired 32 6.3 

Vascular dementia 14 7.7 

Subjective memory 

complaints 

70 

12 

Plasma <2.6 2.6-17.2 

 0 

NS 

AD 43 5.9 

Cognitive impaired 32 4.2 

Vascular dementia 14 0 

Gottfries 

2001 

Subjective memory 

complaints 

70 

12 

RBC <62 62-168 

 0 

NS 

ddd C 

Joosten AD 52 21.2 

1997 Normal (non hospitalized) 83 49 Serum <2.4 2.4-7.2 6.1 .04 dd C 

Andersen- Dementia 105 9 

Ranberg 

2001 Normal 

100 

91 

Serum B 12 / folate 

deficiency nd 

 11 

nd d C 

 Higher score indicates better cognitive function. MMSE: Mini-Mental State Exam; NS: non-significant. 

a

 Incident cases. 

b

 3 year decline.
105

Table 35. Folate level as a predictor of cognitive function in longitudinal studies Author Year 

Baseline Population 

Mean Age 

(yr) 

N Follow- up (yr) Tissue B Vitamin Level Threshold (ng/mL) Outcomes Results OR 9

Elias, 2005 Normal ≥60 705 7.6 Plasma <3.1 Cognitive performance Folate level was 

cognitive f

12 ≤4.4 1.8 (unadj) a 1

MMSE  ≤ 26 47 >4.4 AD (incident) 1.7 (adj) b 0

15 ≤4.4 1.7 (unadj) a 1

Wang 2001 

MMSE  > 26 

75-

101 

47 

3 Serum 

>4.4 

Dementia 

(incident) 1.6 (adj) b 0

AD 1.95 (adj) c Ravaglia 1.1

2005 Normal 74 937 3.8 Serum <5.2 Dementia 1.87 (adj) c 1.2

7.6-10.7 v >10.7 0.8 (adj 1) e 0.7 (adj 2) f 0

AD (clinical 0diagnosis) 73 272 Serum <7.6 v >10.7 AD (clinical diagnosis) 2.5 (adj 1) e 2.3 (adj 2) f 1

1

7.6-10.7 v >10.7 0.6 (adj 1) e 0.4 (adj 2) f 0

0

Clarke 1998 d

AD (histological diagnosis) 77 184 

4 

Serum 

<7.6 v >10.7 

AD (histological 

diagnosis) 5.0 (adj 1) e

3.3 (adj 2) f 

31

Kado 2005 Normal 74 370 7 Plasma bottom quartile v top 3 quartiles Cognitive function decline 1.71 (adj) g 1.
106

Table 35. Folate level as a predictor of cognitive function in longitudinal studies (Continued) Author Year 

Baseline Population 

Mean Age 

(yr) 

N Follow- up (yr) Tissue 

B Vitamin 

Level 

Threshold

(ng/mL) 

Outcomes Results OR 95% CI 

MMSE  β 0.12 

Construction praxis: 

spatial copying, sum 

of drawings  β 1.0 

Language: verbal 

fluency  β 0.76 

Working memory: 

backward digit span, 

longest span 

recalled 

β -0.28 

Tucker, 2005 Normal 67 315 ~3 Plasma 11.5 

Recall memory: 

word lists, total of 3 

trials  β 0.43 

87 <2.2-5.2 v >6.2-15.9 Cognitive decline- 3 yr 2.2 0.96, 4.9 66 <2.2-5.2 v >6.2-15.9 Dementia (incident) 2.2 0.9, 5.2 

Maxwell 2002 3MS  <78 80 

49 

5 Serum 

<2.2-5.2 v 

>6.2-15.9 AD (incident) 2.2 0.9, 5.5 

Seshadri 2002 

Cognitively intact 76 1092 8 Plasma >6.2-15.9 Newly diagnosed AD and dementia Folate level was not indepen

to the risk of dementia or AD 

for age, sex, and ApoE 

Bowirrat 2002 Normal 

≥60 234 1.7 Plasma Lowest v highest tertile AD No significant greater risk t

after adjustment for year 

gender. 

Jones 2002 Normal 

≥75 230 3 nd nd Cognitive decline Vitamin status and Apo 

precipitate the dec

 Higher score indicates better cognitive function. MMSE: Mini-Mental State Exam; NS: non-significant.a Relative risk. b Relative risk, adjusted for age, sex, and education. c Adjusted for all study covariates and homocysteine; no results reported 

without adjustment for homocysteine. 

d Retrospective study. e Adjusted for age and sex. f Adjusted for age, sex, smoking, social class, and g Adjusted for age, sex, education, baseline physic
107

Table 36. Folate level as a predictor of cognitive function in case-control studies and cross sectional studies Author Year Population 

Mean Age 

(yr) 

 N Tissue Folate Level (ng/mL) Results OR 95% CI 

3.5-5.0 v >5.0 1.3 0.5, 3.7 

AD ~80 75 Plasma <3.5 v >5.0 1.6 0.6, 4.2 

7.6-10.7 v 

>10.7 

0.6 (adj 1) a

0.4 (adj 2) b 

0.2, 1.6 0.1, 1.5 

Mizrahi 2004 AD (histological 

diagnosis) 77 184 Serum <7.6 v >10.7 5.0 (adj 1) a 3.3 (adj 2) b 3.1, 8.2 1.8, 6.3 

74 6.0-8.6 v >8.6 2.1 (adj) c 0.7, 6.4 

AD 79 55 <6.0 v >8.6 3.7 (adj) c 1.3, 10.7 

81 6.0-8.6 v >8.6 1.0 (adj) c 0.4, 2.8 

Quadri 2004 Cognitive 

impaired 76 55 

Serum 

<6.0 v >8.6 3.4 (adj) c 1.3, 8.7 

Anello AD 71 181 2004 Normal 70 180 Plasma nd 0.95 d 0.91, 1.00 

AD lesions 15 8.8 Snowdon 

2000 

AD no lesions 

91 

15 

Serum 

11.9 

r = 

−0.80 e

r= 

−0.14 f

4.4 ng/mL decrease in serum folate was associated w

one-point decrease for the MMSE score 

Argyriadou 2001 

Cognitive impaired 

65-

85 536 nd <1.8 v >1.8 3.8 0.9, 15.2 

 Higher score indicates better cognitive function. MMSE: Mini-Mental State Exam; NS: non-significant a Adjusted for age and sex. b Adjusted for age, sex, smoking, social class, and ApoE ε4. c Adjusted for age, sex, education, and creatinine. d The lowest folate tertile compared with the highest tertile after adjusting for age, sex, education, and creatinine. e Age-adjusted correlation between folate and the severity of atrophy among AD with significant histological lesions in the autopsy. f Correlation with the mean number of neurofibrillary tangles in the neocortex with significant histological lesions in the autopsy.
108 

B Vitamin-Homocysteine Interaction With Cognitive Function 

 Testing the hypothesis of a potential effect of the interaction between homocysteine and 

B vitamins on cognitive function was not the primary purpose for this report. Consequently, 

studies that did not consider B vitamins as independent predictors of cognitive function and 

limited their analyses to homocysteine or the interaction of homocysteine and B vitamins only, 

were not included in our review. 

 It is well established that B vitamin status (mostly folate, B12, and possibly B6) is a major 

determinant of homocysteine level.143-145 Among elderly subjects in the Framingham study, for 

example, two-thirds of cases of high homocysteine were associated with at least one vitamin 

concentration below the 70th percentile.143 In addition, studies have consistently found that 

homocysteine levels can be reduced with B vitamin treatment.123 Furthermore, numerous studies 

– including several evaluated in this review of B vitamins – have demonstrated an association 

between higher homocysteine levels and worsened cognitive function. 18,96,114,115 Elevated 

homocysteine levels putatively may cause cognitive decline through both neurotoxic and 

vasotoxic effects.146 Of note, almost all trials of combinations of B vitamins – and several 

interventions with individual B vitamins – were designed with the intent of lowering 

homocysteine levels. Among studies that reported data on associations between cognitive 

function and both B vitamins and homocysteine, most found that the association of homocysteine 

and cognitive function was statistically independent of B vitamin levels; thus homocysteine 

levels were predictive of cognitive function even after correction for B vitamin deficiency. This 

statistical independence was found in both cross-sectional studies 84,110,128,141 and longitudinal 

studies,18,115 but does not imply a biological independence. Several studies, both crosssectional112,147 and longitudinal96,114 found evidence of interactions between homocysteine and 

either folate, B12, or combined folate, B6, and B12. 

 Interpretation of the relative effect of different homocysteine levels on any interactions 

between B vitamin status and cognitive function is more problematic. Given that homocysteine is 

associated with cognitive decline and that B vitamins affect homocysteine levels, it is 

hypothesized that much of the B vitamins’ role in preventing cognitive decline is through their 

effect on maintaining low homocysteine levels and thus any associations between B vitamin 

status and cognitive function would not be expected to be independent of homocysteine level. 

 However, among the five longitudinal studies that analyzed potential interactions between 

homocysteine and B vitamins on their association with cognitive decline, the MacArthur Studies 

of Successful Aging (MSSA),112 the Conselice Study of Brain Aging (CSBA),115 and the 

Veterans Affairs Normative Aging Study (VANAS)96 each found that baseline serum folate level 

(and also dietary folate in VANAS) was significantly associated with various measures of 

cognitive decline, independent of homocysteine or vitamins B6 or B12. Each set of authors 

conclude that the independent contribution of low folate to cognitive impairment may affect the 

development of cognitive impairment through mechanisms other than homocysteine’s direct 

neurotoxicity. Of note, VANAS found independent effects of folate only for constructional 

praxis (figure copying), while MSSA analyzed a summary cognitive score based on several tests 

and CSBA analyzed diagnosis of AD. In contrast, both the Framingham Study18 and the 

Framingham Offspring Study114 found no association between folate level and cognitive 

function. 
109 

B Vitamin Adverse Events 

 To answer the question regarding adverse events we reviewed all 39 prospective human trials 

of B vitamin interventions that we retrieved for possible inclusion regarding effect of treatment 

on age-related neurocognitive disorders. Three of these articles had multiple studies or study 

arms, thus there were 43 separate cohorts of subjects who received specific B vitamin treatments. 

Eight of these studies were rejected from analyses above either because of inclusion of ineligible 

populations or reporting only on outcomes not of interest for the purpose of this review. 

 Among the 43 studies/cohorts, only 10 reported any information on adverse events (Table 

37). Only two of these reported that any adverse events occurred. 

 Three articles reported on adverse events related to thiamine (B1) or thiamine derivative 

interventions in four studies;61,62,64 two additional studies did not report on adverse events. In 

three studies, there were no adverse events, among 37 subjects total who took either 3 g thiamine 

per day or fursultiamine 100 mg per day for 1 to 3 months. All included patients with AD. The 

fourth study, also of patients with AD, found that 17 subjects all tolerated well thiamine doses 

between 4 and 6 g per day a month at a time. Among a subset of 7 subjects who took higher 

doses up to 8 g per day, two reported nausea and indigestion at doses of 7.0 and 7.5 g per day, 

but subsequently tolerated the same dosages in later months. 

 The single intervention study of riboflavin (B2) did not report on adverse events. 

 None of 4 studies of pyridoxine (B6) reported on adverse events. 

 Among 18 studies of cobalamin (B12), only one reported on adverse events.70 In a 12 week 

study of a cohort of 10 patients with AD who were treated with intravenous mecobalamin 500 μg 

3 times a week for 8 weeks, there were no side effects detected in laboratory tests and there were 

no patient complaints. 

 Three of eight studies of folate supplementation reported on adverse events.79,81,148 The three 

studies evaluated 59 subjects who took either 15 mg or 20 mg folate per day. The two studies of 

patients with dementia reported no adverse events over 10 weeks or an unreported duration. In a 

cohort study by McGeer 1972 of 18 patients with PD who were treated with 15 mg folate per day 

for 14 to 182 days, three reported minor symptoms of “buzzing in the ears,” “a jittery feeling,” or 

“sleeplessness.” No mental changes, weight loss, or gastrointestinal symptoms were reported by 

patients. 

 One 2 year randomized trial reported that combination B6 (5 mg per day) and B12 (250 mg 

per day) was well tolerated in 158 healthy subjects (siblings of patients with premature 

atherosclerotic disease).149

 The two studies that evaluated combination B12 and folate did not report on adverse events. 

 One of three studies of combination B6, B12, and folate reported on adverse events.86 In a 

cohort study of 63 patients with AD who were treated with daily doses of 50 mg B6, 1 mg oral 

B12, and 50 mg folate, no adverse events were reported over 8 weeks. 

 Overall, in 10 studies that included 254 subjects taking B vitamin supplements (and 79 

subjects taking placebo), two subjects with AD in one study reported mild gastrointestinal 

complaints with high dose thiamine, which they were later able to tolerate, and three patients 

with PD reported possibly neurological complaints with folate. No serious adverse events were 

reported. 
110 

Table 37. Reported adverse events in B vitamin intervention studies 

Study, Popu- N 

Year Dose / Day lation 

Mean 

Age (yr) Duration Design Tx Cx Adverse Events 

Thiamine (B1) 

Meador, 

1993 

Study 1 

3 g AD 71 1 mo Crossover 17 

None 

Meador, 

1993 

Study 2 

4-8 g AD 71 13 mo a Crossover b 17 

All tolerated doses up to 6 

g/day well without any side 

effects 

2 (of 7) subjects reported 

nausea and indigestion at 

doses of 7.0 and 7.5 

g/day, but subsequently 

tolerated the same 

dosages in later months. 

Blass, 1988 3 g AD 72 3 mo Crossover 

11 None 

Mimori, 

1996 

Fursultiamine 

100 mg AD 72 12 wk Cohort 9 None 

Riboflavin (B2) No studies

Pyridoxine (B6) No studies

Cobalamin (B12) 

Ikeda, 1992 500 μg 

3x/wk IV AD 71 12 wk Cohort 10 None 

Folate 

Yukawa, 

2001 c 15 mg Dementia 56 nd Cohort 36 None 

McGeer, 

1972 15 mg PD nd 14-182 

days d Cohort 18 

1 buzzing in the ears, 1 

jittery feeling, 1 

sleeplessness. 

No mental changes, 

weight loss, or 

gastrointestinal symptoms. 

Sommer, 

2003 20 mg Dementia 77 10 wk RCT 5 6 None 

Pyridoxine (B6) + Folate 

Vermeulen, 

2005 e B6: 5 mg 

Folate: 250 mg Healthy 46 2 yr RCT 68 73 None 

Cobalamin (B12) + Folate No studies

Pyridoxine (B6) + Cobalamin (B12) + Folate

Aisen, 2003 

B6: 50 mg 

B12: 1 mg 

Folate: 50 mg 

AD 71 8 wk Cohort 63 

None 

N, number of subjects; Tx, vitamin B treatment, Cx, control; 

a

 1 month each at various doses, including 1 month of placebo. b

 Single cohort of subjects all changing doses in a set sequence. 

c

 Study did not meet eligibility criteria for evaluation of effect of B vitamin treatments. d

 Mean 45 days. 

e

 Study did not meet eligibility criteria for evaluation of effect of B vitamin treatments. 

General Vitamin B Safety. As noted in Table 38, the Institute of Medicine (IOM) concludes 

that there are no reports of adverse events for any of the evaluated B vitamins within the range of 

the RDA and up to the Upper Limit (UL); although they acknowledge that data on adverse 

events for all the vitamins are limited. 
111 

 With a few exceptions and caveats, review articles on the safety of the B vitamins have 

concluded that B vitamin supplementation is safe. An older review by Marks in 1989,150

concluded that for all the B vitamins, at levels of intake approximately equivalent to those found 

in a good mixed diet, vitamins are beneficial and show no adverse reactions. He concluded that 

safe doses for thiamine are at least 50 to 100 times the RDA (i.e., above 100 mg daily); safe 

doses for riboflavin are substantially above 100 times the RDA (also above 100 mg daily); safe 

doses for pyridoxine are up to 200 mg daily (over 100 times the RDA); safe doses for oral 

cyanocobalamin are as high as 30 mg daily (over 10,000 times the RDA); and safe doses for folic 

acid of 50 to 100 times the RDA (up to about 20 mg). 

 The primary safety concern raised regarding thiamine involves rare reports of anaphylaxis 

after single oral doses in the range of 5 to 10 g or intravenous doses.150,151 However, one 

reviewer, Snodgrass, in 1992 theorized, primarily based on animal studies, that high dose 

intravenous thiamine – generally used in patients suspected of having Wernicke’s 

encephalopathy, in part to prevent seizures – may actually be causing seizures. However, as 

noted by Snodgrass, a large report of almost 1000 patients receiving intravenous thiamine rarely 

resulted in complications.152 Only one patient had a major adverse reaction (generalized pruritis). 

 We found no safety concerns related to riboflavin. 

 Long-term, high-dose pyridoxine is well known to cause a reversible neuropathy. A literature 

review in 1986 by Cohen et al. noted that adults receiving more than 500 mg per day are at risk 

for developing sensory neuropathy, while short-term courses or lower daily doses does not result 

in adverse neurological changes.153 However, as noted by both Marks and Snodgrass, there have 

been reports of neuropathy with doses as low as 200 mg per day. 150,151

 Prior to the addition of carbidopa to L-dopa treatment for PD, it was frequently noted that 

pyridoxine supplementation resulted in a loss of the L-dopa effect, with an increase in 

Parkinsonian symptoms.154-159 This effect is due to inhibition of peripheral decarboxylation of 

L-dopa.160 However, use of peripheral decarboxylase inhibitors such as carbidopa with L-dopa 

blocks the drug interaction, such that the efficacy of the two drugs is unaffected by 

pyridoxine.158-160

 We found no safety concerns related to cobalamin, either in oral or parenteral form. 

 A systematic review of the safety of folic acid supplements was performed by Campbell in 

1996, prior to the policy of mandatory grain fortification in the US.161 Several potential safety 

issues were discussed including masking of thiamine deficiency, neurotoxicity, drug antagonism, 

reduced zinc absorption, and hypersensitivity. Folate repletion in B12 deficient individuals is 

well-known to post the anemic manifestations of pernicious anemia while allowing posterolateral 

spinal cord degeneration to progress. This effect is generally seen only with higher doses of 

folate (≥5 mg daily) and can be avoided by testing for B12 deficiency.161,162 The question of 

neurotoxicity has been tested in patients with PD as described above (McGeer 1972). Several 

case reports of increased frequency of seizures in epileptics have been reported with folate doses 

of 5 to 30 mg;162 although this possible effect may in part be due to interactions between folate 

and anti-convulsant drugs due to their effect on folate metabolism.161 However, no drugs used 

specifically for neurodegenerative disorders interfere with folate metabolism. Campbell also 

found a limited number of case reports describing hypersensitivity reactions to oral and 

parenteral folic acid, but concluded that the reactions were probably to contaminants in the folate 

formulations. 
112 

Table 38. Institute of Medicine Dietary Reference Intakes of B vitamins and adverse effects 

Nutrient Life Stage 

Group RDA ULa

 Adverse effects of excessive consumption 

Males (mg/d) 

≥31 yr 1.2 ND 

Females 

Thiamine 

≥31 yr 1.1 ND 

No adverse effects from food or supplements have 

been reported. Because data on the adverse effects 

of thiamin are limited, caution may be warranted. 

Males (mg/d) 

≥31 yr 1.3 ND 

Females ND 

Riboflavin 

≥31 yr 1.1 ND 

No adverse effects from food or supplements have 

been reported. Because data on the adverse effects 

of riboflavin are limited, caution may be warranted. 

Vitamin B6 Males (mg/d) 

31-50 yr 1.3 100 

≥50 yr 1.7 100 

Females 

31-50 yr 1.3 100 

Comprises a group of 3 

vitamers: pyridoxal, pyridoxine, 

pyridoxamine; and 

5’-phosphate coenzymes of 

each vitamer ≥50 yr 1.5 100 

No adverse effects from food or supplements have 

been reported. Because data on the adverse effects 

of B6 are limited, caution may be warranted. 

Sensory neuropathy has occurred from high intakes of 

supplemental forms. 

Males (μg/d) 

≥31 yr 2.4 ND 

Females 

Vitamin B12 

Including its coenzymes 

methylcobalamin and 

adenosylcobalamin ≥31 yr 2.4 ND 

No adverse effects from food or supplements have 

been reported. Because data on the adverse effects 

of B12 are limited, caution may be warranted. 

Folate Males (μg/d) 

≥31 yr 400 1000

Females 

Note: Given as dietary folate 

equivalents (DFE). 1 DFE = 1 

μg food folate = 0.6 μg of folic 

acid from fortified food or as a 

supplement consumed with 

food. 

≥31 yr 400 1000

Masks neurological complication in people with vitamin 

B12 deficiency. 

No adverse effects from food or supplements have 

been reported. Because data on the adverse effects 

of folate are limited, caution may be warranted. 

The UL for folate applies to synthetic forms obtained 

from supplements and/or fortified foods. 

Derived from Institute of Medicine report accessed at www.iom.edu/Object.File/Master/7/296/0.pdf via 

www.nal.usda.gov/fnic/etext/000105.html (accessed July 27, 2005). 

RDA = Recommended Daily Allowance; UL = Upper Limit. 

a UL = The maximum level of daily nutrient intake that is likely to pose no risk of adverse effects. Unless otherwise 

specified, the UL represents total intake from food, water, and supplements. Due to lack of suitable data, ULs 

could not be established for thiamin, riboflavin, or vitamin B12. In the absence of ULs, extra caution may be 

warranted in consuming levels above recommended intakes. 
113 

Berries 

 In this section, we summarize the results from human and animal or in vitro studies of berries 

and/or the constituents in berries in relation to age-related neurodegenerative disorders. The four 

Key Questions to be answered are as follows: 

1. What are the constituents in berries with beneficial nerve- and brain-related health effects 

(from in vitro, animal, and human studies)? 

a. In what other food sources are these constituents found? 

2. What is the evidence regarding mechanisms of action of berry constituents for 

preventing, decreasing the rate of progression of, or reversing the neurological changes 

associated with age-related neurodegenerative conditions, including Parkinson’s or 

Alzheimer’s disease? 

3. What is the evidence that the constituents of berries can prevent, decrease the rate of 

progression of, or reverse the neurological changes associated with age-related 

neurodegenerative conditions, including Parkinson’s or Alzheimer’s disease in humans 

a. Is the source, species, dose, composition, characteristics, or processing of berries 

and berry constituents related to the effect of the intervention? 

4. What adverse events in humans have been reported in the literature for the constituents in 

berries? 

a. Do the frequency of adverse events vary with source, dose, or other evaluated 

factors? 

 Findings are presented in the order of the Key Questions. 

 Searches of the MEDLINE® and CAB AbstractsTM databases for human, animal, and in vitro 

studies yielded 4,633 citations. After screening of the titles and abstracts, 151 articles were 

retrieved for examination. We retrieved an additional 20 articles identified from review articles, 

study reference lists, and domain experts. One human study and 18 animal or in vitro studies 

(with 19 experiments) were included in this review. Of note, 16 (89%) of these studies have been 

conducted by a single group of investigators at the Jean Mayer USDA Human Nutrition 

Research Center on Aging at Tufts University both with and without the cooperation of other 

research centers. 

 Qualifying studies are presented in summary tables in the appropriate sections. Details 

regarding all included studies are available in the evidence tables*

Constituents in Berries 

 Berries are generally high in fiber and some species may be high in vitamin C. Folate is the 

major B vitamin in some berries, although it does not contribute a substantial amount to a typical 

 

* Appendixes cited in this report are provided electronically at 

http://www.ahrq.gov/downloads/pub/evidence/pdf/berry/berry.pdf.
114 

diet compared to other food items (Table 39). Complete nutrient contents of berries can be found 

in the USDA National Nutrient Database for Standard Reference 

(www.nal.usda.gov/fnic/foodcomp/search/). Like other fruits or vegetables, berries also contain 

various phytochemicals or phytonutrients, which might have antioxidant or anti-inflammatory 

effects. Flavonoids are believed to be the main antioxidants in berries. The flavonoid contents of 

various berries can be accessed in the USDA database for the “Flavonoid Contents of Selected 

Foods.”163 Currently, there is no standard nutrient database for other phytochemicals in fruit and 

vegetables. Research has derived some composition data on the anthocyanins and phenolics 

contents in diverse small fruits, including berries.164,165 Of the three included studies that 

evaluate the effects of the constituents in berries, only a limited number of the numerous 

constituents in berries have been examined. These included tannins (procyanidin and 

prodelphinidin), anthocyanin and phenolics, from various berries. 

Table 39. USDA nutritional facts on selected raw berries (1 cup) a

Fresh fruit Weight Fat Protein Fiber Sugar Vitamin

A 

Vitamin 

C Potassium Thiamine Riboflavin VitaminB6 Folate

Blackberries 144 g 1 g 2 g 8 g 7 g 308 IU 30 mg 233 mg 0.03 mg 0.04 mg 0.04 mg 36 μg

Blueberries 145 g 0 g 1 g 4 g 14 g 78 IU 14 mg 112 mg 0.05 mg 0.06 mg 0.08 mg 9 μg 

Strawberries 147 g 0 g 1 g 3 g 7 g 18 IU 86 mg 225 mg 0.04 mg 0.03 mg 0.07 mg 35 μg

a

 Nutrient data were obtained from the USDA Nutrient Database for Standard Reference 

(www.nal.usda.gov/fnic/foodcomp/search/)

Antioxidants in Berries 

 Antioxidants have protective effects against free radicals, highly reactive substances that 

result from normal metabolism and from exposure to environmental factors like cigarette smoke 

and ultraviolet light. Free radicals cause cellular damage by attacking the body’s cell 

membranes, proteins, and DNA. Berries, such as blueberries, blackberries, cranberries, black 

raspberries, raspberries, and strawberries, have higher total antioxidant capacity than other fruits 

or vegetables, according to the commonly used oxygen radical absorbance capacity (ORAC) and 

ferric-reducing ability of plasma (FRAP) assays.164,166-168 The ORAC assay is based on an 

antioxidant’s ability to react with or neutralize free radicals generated in the assay systems. The 

FRAP assay measures the reduction of ferric iron (Fe3+, oxidized form) to ferrous iron (Fe2+, 

reduced form) in the presence of antioxidants.167

 Flavonoids are members of the polyphenol family, important phytochemicals derived from 

plants and having a combination of anti-oxidative, anti-viral, and anti-carcinogenic properties 

(Figure 2).Although the predominant flavonoid depends on variety and species, flavonoids are 

found mostly in celery, cranberries, onions, kale, dark chocolate, broccoli, apples, cherries, 

berries, tea, red wine, purple grape juice, parsley, soybeans, tomatoes, eggplant, and thyme.163

Anthocyanins and/or proanthocyanidins (a class of flavonoid compounds) are the main 

antioxidants compounds found in berries, and they might have anti-inflammatory effects. 
115 

Animal and In Vitro Studies: Mechanisms of Action 

 All studies related to mechanisms of action of berry constituents (or whole berries) have been 

performed in animal or in vitro models. Among 18 animal or in vitro studies (with 19 

experiments) investigating berries and neurocognitive function or processes, four studies169-172

examined the effects of specific berry constituents on animal performance in neurocognitive 

testing or on their brain biochemistry. The remaining 14 studies (with 15 experiments)173-186 used 

berry extracts that supplemented normal diet or were added to in vitro media. 

Effects of the Constituents in Berries 

Study Descriptions. Four studies, two of high quality and two of moderate quality, were 

included in this section. 169-172 Of the four studies, only a limited number of the numerous 

constituents in berries have been examined. These include tannins, anthocyanin and phenolics, 

from various berries (Table 40). Each study examined the effects of different berry constituents. 

Overall Effects. Saija 1990 found that injecting 200 mg/kg bilberry anthocyanin extracts 

intraperitoneally in adult rats for 3 days significantly increased rats’ brain uptake of 

triiodothyronine (T3).169 The findings generated the hypothesis that the berry anthocyanins might 

cross the BBB and block the 5’-deiodinase activity and, therefore, the intracerebral formation of 

T3 from T4, thereby simultaneously stimulating T3 transport into the brain. 

 Wang 1996 measured the concentrations of tannins from 18 plant sources that were required 

for 50 percent inhibition (IC50 values) of brain protein kinase C (PKC). Wang found that 

blueberry, red currant, and gooseberry tannins have similar IC50 values as other plant tannins. 

Additionally, the IC50 values of these three tannins were not significantly different from each 

Figure 2. Polyphenol family structure 

(Poly)phenolics

Simple Phenolics Flavonoids Hydroxycinnamate

Derivatives

Anthocyanins Flavanols /

Flavans Flavanones Flavonols Flavones Isoflavones

EXAMPLES:

Anthocyanins: cyanidin, malvidin, petunidin etc. (all have sugars attached) 

Flavanols / Flavans: catechin, epicatechin, proanthocyanidins 

Flavanones: hesperetin, naringenin, eriodictyol 

Flavonols: quercetin, myricetin, kaempferol (most have sugars attached) 

Flavones: apigenin, luteolin 

Isoflavones: daidzein, genistein, glycitein 

Hydroxycinnamates: chlorogenic acid 

Simple Phenolics: phloridzin 
116 

other. No measurements were made regarding possible effects of PKC inhibition.171 PKC is 

known to be involved in eukaryote cell signal transduction. 

 Andres-Lacueva 2005 assessed whether anthocyanins might be found in brain areas 

associated with cognitive performance following blueberry supplementation in old rats, and the 

effects of the blueberry supplementation in rats’ diet on the performance of Morris Water Maze. 

The rats’ standard diet was augmented with either blueberry extracts or dried corn, which 

replaced 2 percent of the diet. They found that following 10 weeks of dietary supplementation 

with 2 percent of blueberry extracts, anthocyanins were found in the brains of all rats fed the 

blueberry diet, while no anthocyanins were detected in the brains of rats fed the corn diet. There 

was no difference in Morris Water Maze escape latency learning over days between blueberryand corn-fed rats. However, among blueberry-fed rats, there was a significant negative 

correlation between day 4 re-learning (mean latency for trials 2-6) and number of total 

anthocyanins measured in the cortex (r=-0.78, P=0.02); i.e., as anthocyanin number increased, 

the latency to find the platform decreased. Also as anthocyanin number increased, there was a 

trend for the rat to spend more time searching in the location of the previous platform location on 

the probe trial (r=0.91, P=0.09). 

 Shukitt-Hale 2005 is the only study that compared the effects of specific berry constituents 

on neurocognitive outcomes. They examined aged rats’ performance in neurocognitive testing, 

along with possible mechanisms of action regarding brain biochemical changes. The rats’ 

standard diet was augmented with each of four berry extracts, which replaced 2 percent of the 

diet. The total phenolics in these four berry extracts were similar, while black currant or 

boysenberry extracts had higher amount of anthocyanin than blueberry or cranberry extracts. 

They tested whether the loss of the ability of cells to increase the biomarker heat shock protein 

(HSP70), as a means to respond to insults such as ischemia, inflammatory agents and reactive 

oxygen species, may contribute to the age-related declines in both neuronal and behavioral 

functioning. In addition, striatal dopamine release was assessed because it is believed to be a 

sensitive marker for assessing striatal muscarinic sensitivity in aging. 

 Blueberry and cranberry extracts, but not black currant and boysenberry extracts, had a 

significant beneficial effect on performance by the rats on the inclined screen test, one of five 

psychomotor functions tested. The cranberry extract group (that had improved function) and the 

black currant extract group (that did not have improved function) had significantly increased 

striatal dopamine release compared to the control and boysenberry extract groups; the blueberry 

extract group was not examined for dopamine release. 

 HSP70 responsiveness in the blueberry extract group was significantly higher than the control 

group and the cranberry extract group showed a trend toward higher HSP70 responsiveness than 

the control group, while the black currant and boysenberry extract groups did not show such 

responsiveness. Furthermore, rats’ neurocognitive performance, as measured by latency to fall 

from the inclined screen, was positively related to the percent change in HSP70 (r=0.39, P=0.05). 

 The inclined screen, dopamine release and HSP70 results all suggested that there is a range of 

effectiveness associated with the different berry extracts. However, it does not appear that the 

anthocyanin component is solely responsible for these improvements, as the black currant and 

boysenberry extracts are higher in anthocyanin level, but not as effective in improving motor 

performance. Of note, there was no significant effect on rats’ performance in the Morris Water 

Maze among the four berry extract groups when compared to control. This test is among the more 

standardized and validated tests of neurocognitive and behavioral function in rodents.187
117 

Summary. Of the four included studies, only a limited number of the numerous constituents in 

berries have been examined. Each study examined the effects of different berry constituents. One 

study showed that injecting 200 mg per kg bilberry anthocyanin extracts intraperitoneally in 

adult rats for 3 days significantly increased rat’s brain uptake of T3. Another study measured the 

IC50 of brain PKC for 18 plant tannins in an in vitro study. Blueberry, red currant, and 

gooseberry tannins have similar IC50 values as other plant tannins. Additionally, the IC50 values 

of these three tannins were not significantly different from each other. However, the biological 

significance of this in vitro study in live animals is unknown. Only the most recent studies 

evaluated the effects of specific berry constituents on neurocognitive outcomes. Two studies 

examined aged rats’ performance in neurocognitive testing: both found no difference in the 

learning performances; one found improvements in motor performances. Of these, one study also 

demonstrated that the anthocyanins in blueberry extracts were able to cross the BBB and the 

number of the total anthocyanins measured in the brain is associated with rats’ learning 

performance. Another study examined the possible mechanisms of action regarding brain 

biochemical changes to rats’ performance in neurocognitive testing. The results suggested that 

there is a range of effectiveness associated with the different berry extracts as shown in the 

results from rats’ performance in the inclined screen test, dopamine release and heat shock 

protein. However, it does not appear that the anthocyanin component of the berry extracts is 

solely responsible for these improvements, as the black currant and boysenberry extracts are 

higher in anthocyanin level, but not as effective in improving motor performance. 
118

Table 40. Effects of constituents in berries on animal’s performance in neurocognitive testing or on their brain biochemistry 

Study, Year 

Model 

Age/Weight 

Duration Intervention N Control N Neurocognitive Test 

Group 

Results P Biochemical Measures 

Saija, 1990 Rats S-D 300-350 g 3 days Bilberry anthocyanins a 200 mg/kg i.p. nd Vehicle nd Brain uptake of T3 

Blueberry tannins d Red currant tannins f 

Wang, 1996 Rat brain PKC c Gooseberry tannins g (Other tannins) Brain PKC inhibition 

MWM- time to reach platform 0 Andres- Lacueva, 

2005 

Rat, male 

F344 19 mo 

7-10 wk 

Blueberry extracts 

2% of diet 8/4 h

NIH-31 w/ 2% dried corn 

8/4 

MWM- time searching 0 

Anthocyanin profile distribbrain regions (cerebellumstriatum; hippocampus) 

BB An: 1.3 Ph: 1.2 nd Rod Walk All 0 BC An: 8.7 Ph: 2.9 nd Wire Suspension All 0 BS An: 9.2 Ph: 2.0 nd Plank Walk All 0 

nd 

NIH-31 nd 

BB + .04 

Dopamine release 

 BC 0  BS 0 

Inclined Screen 

CB + .001 

 Accelerating Rotarod All 0

Hippocampal HSP70 

ShukittHale, 2005 Rat, male F344 19 mo 13-16 wk CB An: 3.3 Ph: 3.6 

 Morris Water Maze All 0

An = anthocyanin (mg/g extracts), BB = blueberry extracts, BC = black currant extracts, BS = boysenberry extracts, btw = between, CB = cranberry extracts, F344 = Fprotein 70, i.p. = intra-peritoneal, N/A = not applicable, nd = no data or not done, NS = not statistically significant, Ph = total phenolics (mg/g extracts), PKC = protein kDawley, T3 = triiodothyronine, MWM = Morris Water Maze. + Berry-fed animals performed better than non-berry-fed animals 0 No difference in performance – Berry-fed animals performed worse than non-berry-fed animals a Extract containing up to15 anthocyanins. b A significant increase in T3 transport into frontal cortex, temporoparietal cortex, occipital cortex, hippocampus, thalamus, hypothalamus and brain-stem, but no signif

striatum, inferior colliculus, and cerebellum. 

c Study measured the concentrations of 18 plant tannins required for 50% inhibition (IC50 values) of brain PKC. d Containing 77% procyanidin and 23% prodelphinidin. e Compared to non-berry tannins. f Containing 78% procyanidin and 22% prodelphinidin. g Containing 96% procyanidin and 4% prodelphinidin. h 8 animals per group for neurocognitive test between 7 and 8 weeks after receiving the diets; brains from 4 animals per group were harvested for brain biochemical m
119 

Effects of Berry Extract Supplementation 

 Berry extracts were used to supplement animals’ diet or added to in vitro study media in 14 

studies with 15 experiments that examined animal’s performance in neurocognitive testing or 

brain biochemistry or histology.173-186 Of these, two studies used specific animal or in vitro 

models of AD. The remaining 13 studies used adult or aged rat models. All of these studies 

(including the rat neurocognitive function study described above) are from the same group of 

investigators. 

Study Descriptions. Only limited types of berry extracts were examined across the 14 studies 

with 15 experiments (Table 41). Blueberry extracts were used in 11 studies, of which only one 

study specified the species of blueberries (i.e., “wild” vs. “tif-blue” blueberries, a variety of 

rabbiteye blueberry).186 Strawberry extracts were used in 11 studies, none of which reported the 

species. Seven of these studies used both blueberry and strawberry extracts, including one study 

that used five different berry extracts, including blueberry, strawberry, black currant, 

boysenberry, and cranberry extracts.181 All berry extracts were freeze-dried and aqueous 

extracted, prepared by homogenizing, centrifuging, and then freeze drying. All 13 studies that 

used adult or aged rat models were based on a single central hypothesis, namely that the increase 

in dietary antioxidant levels (by supplementation with berry extracts) might decrease the aginginduced oxidative stress (and/or various physiological changes due to the increased oxidative 

stress) thus reversing the age-related neurodegenerative deficits. However, the studies did not 

elaborate on which “antioxidants” in these berry extracts might be responsible for the effects. 

With a similar central hypothesis, the two studies of animal or in vitro models of AD further 

examined the effects of berry extracts on fibrillar amyloid β deposits in mice’s brain and on Ca2+

recovery following amyloid β treatment in vitro.180,181 Most studies are of high quality. Studies 

that were downgraded to moderate or poor quality were due to poor reporting, no repeated 

measures, or lack of neurocognitive function measures. 

Overall Effect 

Blueberry extract supplementation. The effects of blueberry supplementation on animal’s 

performance in neurocognitive testing or brain biochemistry or histology in adult or aged rat 

models are summarized in Figure 3. In these nine studies, blueberry extract supplementation 

showed positive or protective effects on all biochemical markers and histology findings 

examined in rats’ brain, although only some of the neurocognitive tests and psychomotor 

functions were significantly improved in blueberry-extract-fed rats. Only one study correlated 

the biochemical markers changes in rats’ brain with rats’ performances in cognitive function 

tests.175 Nineteen-month-old male F344 rats were fed either the control diet or the blueberryextract diet for 8 weeks before they were tested for Radial Arm Water Maze (RAWM) 

performances. The blueberry-extract diet equaled 2 percent of the control diet supplemented with 

blueberry extracts, which was approximately equivalent to the consumption of 4 g of blueberry 

extract per day. RAWM performance was tested for five consecutive days. Repeated measure 

analysis across days revealed a significant day effect for latency (P<0.0001), suggesting that rats 

in both groups could successfully learn the task on days 1 to 3. The lack of interaction between 

groups suggested that the rate of learning on days 1 to 3 did not differ across groups. On day 4, 

compared to animals fed the control diet, blueberry-extract-fed rats had significantly fewer 

reference memory errors (P<0.05) and total memory errors (P<0.05), and also showed a trend 
120 

towards fewer working memory errors (P<0.06). However, there was no significant difference in 

RAWM performances seen between the two groups on day 5. It was also found that the 

blueberry extract supplementation significantly increased hippocampus insulin growth factor-1 

(IGF-1), IGF-1R, and extracellular-signal-regulated-kinase (ERK) activation. These changes of 

brain biomarkers were significantly associated with the decreases in total memory errors and 

reference memory errors but not working memory errors on day 4. In addition, blueberry extract 

supplementation significantly increased proliferation of precursor cells in the dentate gyrus (or 

neurogenesis) and the neurogenesis was significantly associated with the improvements in 

RAWM tests. Finally, in order to see if neurogenesis, growth factors, and ERK, in combination 

or synergistically, were associated with the improvements in RAWM tests in aged blueberryextract-supplemented rats, the associations between these brain biomarkers were examined. A 

statistically significant positive correlation between ERK activation and IGF-1 and IGF-1R 

levels was found (r=0.75, P<0.05), while the increased IGF-1 and IGF-1R levels, and ERK 

activation were not associated with neurogenesis. 

Strawberry extract supplementation. The effects of strawberry supplementation on animal’s 

performance in neurocognitive testing or brain biochemistry or histology in adult or aged rat 

models are summarized in Figure 4. Nine of 10 studies showed positive or protective effects of 

strawberry-extract supplementation on all of the biochemical markers examined in rats’ brain, 

although only some of the neurocognitive tests and psychomotor functions were significantly 

improved in strawberry-extract-fed rats. No study correlated the biochemical markers changes in 

rats’ brain with rats’ performances in neurocognitive function tests. 

Alzheimer’s disease models. One animal study180 and in vitro study181 used models of AD to 

examine the effects of berry extracts. 

 In the animal study, mice transgenic for amyloid precursor protein (APP) and presenilin-1 

(PS1) mutations were used to model human AD.180 These mice are prone to fibrillar amyloid β

deposits in cerebral cortex and hippocampus early in the life-span with later changes in cognitive 

behavior. Four-month-old transgenic and wild type mice were fed either the control diet or the 

blueberry-extract diet for 12 weeks before they were tested for Y maze performances. The 

blueberry-extract diet was 2 percent of the control diet supplemented with blueberry extracts, 

which was approximately equivalent to the consumption of 4 g of blueberry extract per day. 

Blueberry extract supplementation had a beneficial effect on Y-maze performance in transgenic 

mice but not in wild type mice. In the transgenic mice, there was no significant change in brain 

amyloid β deposits or calcium-dependent phospho-protein kinase Cα (PKCα), while a significant 

increase in brain neutral sphingomyelin-specific phospholipase C (N-Sase), low Km guanosine 

triphosphase (GTPase), ERK, and protein kinase Cγ (PKCγ) activities was found. Furthermore, 

the correlation between these brain biomarkers and the Y maze performances by the mice was 

examined. A positive correlation between GTPase activity and Y-maze alternation was found in 

the striatum but not in the hippocampus or cortex. A negative correlation between N-Sase 

activity and Y-maze alternation was found in the striatum but not in the hippocampus or cortex. 

The correlation between all other brain biomarkers and Y-maze alternation did not reach 

statistical significance. 

 In the in vitro study, COS-7 cells (ATCC) transfected with rat muscarinic receptor subtype 1 

or 3 DNA (M1AchR) were used.181 Five different berry extracts (2 mg per mL blueberry, 2 mg 

per mL black currant, 2 mg per mL boysenberry, 0.5 mg per mL strawberry, or 1 mg per mL 

cranberry extracts) were dissolved in growth media and M1AchR-transfected COS-7 cells were 
121 

subsequently incubated with the treated growth medium. Following these incubations the cells 

were washed with extract-free growth medium prior to testing. Ca2+ Recovery following 0 or 1 

mM dopamine or 0 or 100 μM amyloid β treatment was tested. Recovery was determined by 

assessing the time (within 300 sec) for the Ca2+ level to return to 20 percent of the increase 

following depolarization in the cells that responded. In the absence of pre-treatment (control 

condition) there were significant effects of both dopamine and amyloid β on recovery of the M1-

transfected cells (e.g., control vs. dopamine- or amyloid β-treated cells with no extract pretreatment, P<0.001) and all berry extract pre-treatments did not show any significant effect on 

Ca2+ recovery. However, all five berry extract pre-treatments significantly reduced the 

deleterious effects of dopamine, and blueberry, black currant, boysenberry and cranberry but not 

strawberry, extract pre-treatments significantly reduced the putative toxic effects of amyloid β. 

Summary. Only strawberry and blueberry extracts were used to examine the effects of extract 

supplementation on animal performance in neurocognitive testing or brain biochemistry or 

histology using a normal-aging rat model. The mechanism of actions tested were similar for both 

berry extracts although only one study, using blueberry extract, examined the direct relationship 

between the changes in brain biomarkers and the performance in neurocognitive function tests. 

Blueberry and strawberry extract supplementation showed positive or protective effects on 

almost all biochemical markers and histology findings examined in rats’ brain, although only 

some of the neurocognitive tests and psychomotor functions were significantly improved in these 

berry-extract-fed rats. 

 Only two studies used models of AD to examine the effects of various berry extracts. The 

results suggested that it may be possible to reduce both the deleterious effects of dopamine and 

the putative toxic effects of amyloid β via various berry extracts as shown in the in vitro study. 

Results from the animal study that used mice transgenic for APP and PS1 mutations to model 

human AD showed that the blueberry extract supplementation seemed to have prevented the 

deficits in Y-maze performance seen in the transgenic animals fed the control diets, although it 

did not affect amyloid β deposits. 
122

Blueberry

extracts

Dopam ine release +(1, 5, 9)

Cerebellar ß adrenergic

receptor function +(1)

Oxidative stress +(5)

Synaptosomes Ca2+ recovery

after H2O2 exposure +(5)

GTPase activity +(5)

Cerebellar ISO potentiation of

GABAergic inhibition +(3, 7)

Proliferation of precursor cells

in the dentate gyrus +(11)

Hippocam pus growth factor-1

and growth factor-1R +(11)

Extracellular-signal-regulatedkinase activation +(11)

Brain nuclear factor-kappa B

levels +(12)

Rod waling +(3, 5) 0(7

Plank rotarod waking +

Inclined screen +0(9

Accelerating rotard: latency to f

Morris W ater Maze: Latency 

Radial Arm W ater Maze: refe

memory errors +0(11

Radial Arm W ater Maze: wo

memory errors +0(11

Radial Arm W ater Maze: total 

errors +0(11)

X

X

Object recognition, 1 hr delay 

Operant task / bar pressing, w

ratio reinforcem ent 0(14, 

References:(1) Joseph, 1998A(3) Bickford, 1999(5) Joseph, 1999(7) Bickford, 2000(9) Youdim, 2000(11) Casadesus, 2004(12) Goyarzu, 2004(14) Rabin, 2005A(15) Rabin, 2005B

Indirectassociation

Keys:

Directassociation

X No

association

Figure 3. Summary of the effects of blueberry extract supplementation on animal’s performance in neurocognitive testing histology in adult or aged rat models + Berry-fed animals performed better than non-berry-fed animals 0 No difference in performance – Berry-fed animals performed worse than non-berry-fed animals 
123

Strawberry

extracts

Dopamine release +(1, 2, 5, 8)

Cerebellar ß adrenergic

receptor function +(1, 4)

Oxidative stress +(2, 5)

Synaptosomes Ca2+ recovery

after H2O2 exposure +(2) 0(5)

GTPase activity +(2) 0(5)

Cerebellar ISO potentiation of

GABAergic inhibition +(3, 7)

Morris Water M

Morris Water M

Morris Water Ma

Rod waling 

Wire susp

Plank rotaro

Inclined s

Accelerating 

Accelerating rota

Operant task / ba

ratio reinforc

References:(1) Joseph, 1998A(2) Joseph, 1998B(3) Bickford, 1999(4) Bickford, 1994(5) Joseph, 1999(6) Shukitt-Hale, 1999(7) Bickford, 2000(8) Martin, 2000(14) Rabin, 2005A(15) Rabin, 2005B

Indirectassociation

Keys:

Directassociation

X No

association

Figure 4. Summary of the effects of strawberry extract supplementation on animal’s performance in neurocognitive testing 

histology in adult or aged rat models + Berry-fed animals performed better than non-berry-fed animals 0 No difference in performance – Berry-fed animals performed worse than non-berry-fed animals 
124

Table 41. Effects of berry extracts on animal performance on neurocognitive testing or brain biochemistry or histology 

Study, Year 

Model 

Age/Weight 

Duration (mo) Intervention N Control N Neurocognitive Test 

Group 

Results P Biochemical / Histology Measure 

Normal aging model 

Blueberry extracts 10 g/kg nd Dopamine releasee 

Joseph, 1998A Rats F344, 6-8 mo 2 Strawberry 

extracts 9.4 g/kg nd 

AIN-93 nd Cerebellar ß adrenergic 

receptor function 

MWM: Latency + <.05 Dopamine release (striatalMWM: Distance + <.01 MWM: Memory 0

Ca2+ recovery after H2O2exposure (synaptosomes) 

 Oxidative stress (cerebella

Joseph, 1998B 

Rats, male 

Fischer, 6 mo 8 Strawberry extracts 9.5 g/kg 8a Modified AIN-93 8a

 GTPase activity (striatal) 

Blueberry extracts 10 g/kg nd B + nd 

Bickford, 1999 Rats F344, 6 mo 2 Strawberry 

extracts 9.4 g/kg nd 

AIN-93 Rod walkinge

S + nd 

Cerebellar ISO potentiatioof GABAergic inhibitione 

Bickford, 1999 Rats F344, 6 mo 9 Strawberry extracts 9.4 g/kg nd AIN-93 Cerebellar ß adrenergic re

function 

Blueberry B + <.05 extracts 10 g/kg 10 Rod walking time S + <.05 Dopamine release (striatalStrawberry B + <.01 extracts 9.4 g/kg 10 

Modified AIN-93 10 Rod walking 

(latency to fall) S + <.01 GTPase activity (striatal) 

 B 0 

Wire suspension S 0 Ca recovery after H2O2 exposure (synaptosomes) 

 B 0 

Plank walking S 0 Oxidative stress (striatal) 

 B 0 Inclined screen S 0 B + <.05 Accelerating rotarod time S + <.05  B ~ Accelerating rotarod + .06 

(latency to fall) S 0

 B + <.01 

Joseph, 1999 Rats F344, 19 mo 2 

MWM: Memory (learning trial 1

Æ2) S + <.05 
125

Table 41. Effects of berry extracts on animal performance on neurocognitive testing or brain biochemistry or histology (continu

Study, Year 

Model 

Age/Weight 

Duration (mo) Intervention N Control N Neurocognitive Test 

Group 

Results P Biochemical / Histology Measure 

Rod walking 0Wire suspension/wire hanging 0Plank walking 0

ShukittHale, 1999 Rats C57BL.6NIA, 18 mo 6 Strawberry extracts 1% of diet 10 Modified AIN76 8 

Inclined screen 0

Blueberry B 0 extracts 18.6 g/kg 8 Rod walking asymptote (time improvement) S 0 

B 0

Cerebellar ISO potentiatioof GABAergic inhibition Bickford, 2000 Rats, male F344, 18 mo 2 Strawberry 

extracts 14.8 g/kg 8 

Modified 

AIN-93 14 Rod walking slope 

(rate of learning) S 0

Martin, 2000 

Rats, male F344, 15 mo 8 Strawberry extracts 9.5 g/kg 20 Modified AIN-93 20 Dopamine release (striata

Accelerating rotarod Bw + <.05 (latency to fall) Bt 0 Dopamine release (striata

Bw 0

Blueberry extracts, “wild” 2% of diet 14 Inclined screen 

(latency to fall) Bt ~+ .06 

Plank walking Bw + <.05 (latency to fall) Bt + <.05 

Bw 0

Blueberry extracts, “tifblue” 2% of diet 13 

Modified NIH-31b 12 

MWM (latency to find platform) – trial 1 Bt + <.05 

Bw 0

Youdim, 2000 

Rats, male F344, 17 mo 2 

MWM (latency to find platform) – trial 2 Bt 0

Day 1-3 0Day 4 + <.05 Reference memory errors Day 5 0 Proliferation of precursor 

the dentate gyrus 

Day 1-3 0Day 4 + <.06 Working memory errors Day 5 0 Hippocampus growth fac

(IGF-1) 

Day 1-3 0

Total memory errors Day 4 + <.05 

Day 5 0

Hippocampus growth fac(IGF-1R) 

Casadesus, 2004 

Rats, male 

F344, 19 mo 2 Blueberry extracts 2% of diet 5 NIH-31 5 

Extracellular-signal-regulkinase (ERK) activation 
126

Table 41. Effects of berry extracts on animal performance on neurocognitive testing or brain biochemistry or histology (continu

Study, Year 

Model 

Age/Weight 

Duration (mo) Intervention N Control N Neurocognitive Test 

Group 

Results P Biochemical / Histology Measure 

NIH-31, 15 mo 12 Aged Ctrl + <.01 A

Goyarzu, 2004 

Rats, male 

F344, 15 or 4 mo 4 Blueberry extracts 2% of diet 12 NIH-31, 

4 mo 12 

Object recognition, 1 hr delay Young 

Ctrl 0

Brain NF-κB levelsg 

Blueberry 6 mo pFe 0extracts 2% of diet 4 12 mo pFe 0Strawberry 6 mo pFe 0extracts 2% of diet 4 

Modified 

NIH-31 8 

12 mo pFe 0

Blueberry 6 mo pFe 0extracts + 1.5 Gy 56Fe 

2% of diet 8 12 mo pFe 0

6 mo pFe 0

Rabin, 2005A 

Rat, male 

S-D 175-200 g 2j

Strawberry extracts + 1.5 Gy 56Fe 

2% of diet 8 

Modified 

NIH-31 + 

56Fe 

8 

Operant task / bar pressing, with fixed ratio reinforcement 

12 mo pFe + <.05 

Blueberry Age 9, 12 mo 0extracts 2% of diet 4 Age ?,? 0Strawberry Age 9, 12 mo 0extracts 2% of diet 4 

Modified 

NIH-31 8 

Age ?,? 0

Blueberry Age 9, 12 mo 0extracts + 2.0 Gy 56Fe 

2% of diet 8 Age ?,? 0

Age 9, 12 mo + <.05 

Rabin, 2005B 

Rat, male 

S-D 175-200 g 2j

Strawberry extracts + 2.0 Gy 56Fe 

2% of diet 8 

Modified 

NIH-31 + 

56Fe 

8 

Operant task / bar pressing, with fixed ratio reinforcement 

Age ?,? 0
127

Table 41. Effects of berry extracts on animal performance on neurocognitive testing or brain biochemistry or histology (continu

Study, Year 

Model 

Age/Weight 

Duration (mo) Intervention N Control N Neurocognitive Test 

Group 

Results P Biochemical / Histology Measure 

Alzheimer’s disease model 

Tg + <.05 

Y maze performance W 0 Fibrillar Amyloid β depos

 

Mice Transgenicf, 4 mo 3 3 N-Sase activity (striatal, 

hippocampal & cortex)c 

 

Low Km GTPase activity (striatal)c 

 

Mice Wild type, 4 mo 

12 Blueberry extracts 2% of diet 

3 

Modified NIH-31 

3 ERK activity 

(hippocampal)d 

 

Joseph, 2003 

Phospho PKCα

(hippocampal)c 

PKCγ (striatal, hippocam& cortex)c,e 

Blueberry extracts 2 mg/ml Blackcurrant extracts 2 mg/ml 

Ca2+ Recovery following 0 

1 mM dopamine Rx 

Boysenberry extracts 2 mg/ml Strawberry extracts 0.5 mg/ml 

Joseph, 2004 

COS-7 cells (ATCC) transfected with rat muscarinic receptor subtype 1 or 3 DNA 

Cranberry extracts 1.0 mg/ml 

No fruit extract pre-Rx Ca2+ Recovery following 0 

100 μM Aβ (25-35, 100 μM

Rx 

Aged Ctrl=when compared to the aged controls; Aβ= Rx=treatment; B=Blueberry extracts; Bc=Blackcurrant extracts; Bt=Blueberry extracts, tif-blue; Bw=Blueberry ext

extracts; C=Cranberry extracts; F344=Fischer 344; MWM=Morris water maze; nd=no data or not done; NF-κB=nuclear factor-kappa B; N-Sase=neutral sphingomyelinpFe=after irradiation with 56Fe; PKC=protein kinase C; S=Strawberry extracts; S-D=Sprague-Dawley; Young Ctrl=when compared to the young controls. 

+ Berry-fed animals performed better than non-berry-fed animals 0 No difference in performance – Berry-fed animals performed worse than non-berry-fed animals a The number of animals per group was assumed from the total number of animals reported in the article. b Information was inferred from subsequent publications. Control diet specification was, however, described in detailed as table format in the paper. c 3 regions of brain were examined in this study, including striatal, hippocampus, and cortex. There was no significant effect was found in both groups if the brain regio

parenthesis.
128 

d Striatal and cortex regions were not examined for ERK activities 

e Data not shown 

f Transgenic for amyloid precursor protein (APP) and presenilin-1 (PS1) mutations; prone to fibrillar amyloid beta deposits in cerebral cortex and 

hippocampus and changes in cognitive behavior in later life 

g Brain regions examined including frontal cortex, hippocampus, basal forebrain, stratum and cerebellum. 

h In all regions except the basal forebrain, the difference was significant. 

i In all regions except for the cerebellum, there was no significant difference between the aged rats fed blueberry-enrich diet and the young 

controls. In the cerebellum, the aged rats maintained on the blueberry-enriched diet had significantly higher NF-κB levels than young control. 

Notably, aged rats maintained on the control diet had significantly higher NF-κB levels than young rats maintained on the control diet in all 

regions except the striatum. 

j Diet for 2 months; follow-up for 18 months. 

Human Studies 

 Only one study examined the association between consumption of berries and age-related 

neurodegenerative disorders. In the late 1980s, Golbe et al. (1988) conducted a case-control 

study to examine the association between fruit and vegetable consumption in early life and the 

risk of PD among a group of non-vegetarian PD patients and their same-sex siblings The mean 

age of the participants at the time of survey was 62 years old.188 Seventeen food items including 

fruit, vegetables, nuts, and salad oil or dressing were examined. Patients and same-sex siblings, 

in separate interviews, were each asked whether they or their spouse were more likely to eat each 

item between the time of marriage and age 40 years. Patients and siblings were first categorized 

by whether they consumed more, less, or the same amounts of different foods as their own 

spouses. Patient and sibling pairs (including spouses) were then categorized as concordant or 

discordant in their dietary habits (using an unverified, arbitrary decision process). Using 

discordant patient-sibling pairs, the odds ratio of PD was based on the patients who ate more of a 

food than their siblings compared to those who ate less. It was found that the preference to 

consume blueberries or strawberries was not statistically significantly associated with presence 

of PD. This study was deemed to be of poor quality due to measurement and recall biases, in 

addition to the unusual definitions for the consumption levels of fruit and vegetables, and the 

unverified categorization technique and statistical analysis. 

 We found no human interventional studies or clinical trials that met eligibility criteria and no 

correlational or observational study that evaluated AD. 

Berry Adverse Events 

 The single human study of berry consumption was retrospective, therefore no study provided 

data regarding adverse events from berries in the setting of neurocognitive disorders. An 

electronic search (of MEDLINE® and CAB AbstractsTM) for review and primary articles 

reporting on adverse events related to berries or berry constituents (not including allergic 

reactions or occupational exposures) identified two primary reports and a systematic review. 

This search captured only articles that were tagged for adverse events. 

 Canter and Ernst performed a systematic review of trials of bilberry-extracted anthocyanins 

for night vision.189 They reported no adverse events in any of 12 eligible studies; although they 

did not clarify if adverse events were actually reported in these studies. They also reported in a 

post-marketing study of 2,295 participants, that 94 complained of side effects that were mainly 

gastrointestinal, or related to the skin or nervous system.189,190
129 

 An RCT of blackcurrant seed oil treatment for rheumatoid arthritis reported no dropouts due 

to adverse reactions.191 One abstract of a case report described a man in his 70s, treated with 

digoxin, phenytoin, and warfarin, who had poor appetite and drank only cranberry juice postchest infection.192 After 6 weeks, the patient’s international normalized ratio (INR) was greater 

than 50. The author noted that the Committee on Safety of Medicines has received seven other 

reports of possible interaction between warfarin and cranberry juice leading to changes in INR or 

bleeding. 

131

Chapter 4. Discussion 

Overview 

 Age-related neurocognitive disorders, primarily Alzheimer’s disease (AD) and Parkinson’s 

disease (PD), have a major impact on health and well-being among older Americans. The causes 

of the diseases are not yet well understood, including risk factors and associations with 

environmental factors. While some symptomatic treatments are available, no treatments are 

known to prevent, slow the progression of, or cure either AD or PD. 

 Separate lines of evidence have suggested that B vitamin status may be associated with risk 

and progression of AD and PD and that constituents of various berries may also effect 

progression of the diseases. This report summarizes the evidence for relationships between 

B vitamin status and supplementation, and separately berries, and age-related neurocognitive 

disorders. We summarize animal and in vitro evidence for specific putative mechanisms of 

actions and human studies of B vitamin supplementation or berries as treatments, of associations 

between dietary intake and disease, and associations between B vitamin status and disease. 

 We identified almost 7000 potentially relevant citations regarding B vitamins and almost 

5000 potentially relevant citations regarding berries and neurocognitive disorders and function. 

Of these, we reviewed 85 human studies and 17 animal or in vitro studies of B vitamins and one 

human study and 18 animal or in vitro studies of berries. Among the human studies, the majority 

were cross-sectional studies that correlated B vitamin status with either cognitive function or 

dementia diagnosis. There were relatively few intervention studies, longitudinal dietary intake or 

B vitamin status association studies. The large majority of studies were of poor quality, with 

major deficits. The animal and in vitro studies primarily used otherwise healthy rats or mice on 

either vitamin-deficient or berry-supplemented diets; although several did use specific animal 

models for either AD or PD. 

 Both the human and the animal or in vitro studies were widely heterogeneous in doses used, 

measurement methods, definitions of dementia, cognitive function tests, and/or experimental 

design. 

Main Findings 

B Vitamins 

 This report includes evaluations of vitamins B1 (thiamine), B2 (riboflavin), B6 (pyridoxine 

and related compounds), B12 (cobalamin), and folate. 

Mechanisms of Action. All studies were performed in animal or in vitro models. We 

specifically included studies of neurocognitive function, movement disorders, brain 

neurotransmitters, brain histopathology, expression or function of AD-related genes, and blood 

brain barrier (BBB) or cerebrovascular endothelial function. We excluded studies that used B 

vitamin antagonists. 
132

 In rat studies, thiamine depleted diets result in significantly damaged brain tissue with serious 

neurological pathology resulting in death. Thiamine deficiency also significantly impaired 

performances in several neurocognitive tests. 

 No study examined the effects of riboflavin (B2) on outcomes of interest. 

 No significant effects of B6 supplementation were found for rats learning or cognitive 

function, although there were some beneficial effects on motor function and behaviors. These 

effects, though, were not consistent across the studies and did not show a dose-response 

relationship. 

 One study showed that low dose (1 mg per kg diet) vitamin B12 supplementation alone had 

no significant effect on spontaneous movements and did not improve memory in rats with 

nucleus basalis magnocellularis lesions. 

 In normal animal models, there were no apparent pathologic changes in brain tissue after 

folate deprivation, although there was a degenerative appearance of the cerebrocortical 

microvascular wall. One study found that folate was protective against a sub-toxic dose of 1-

methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), which otherwise causes profound motor 

dysfunction similar to PD. Using the AD model of amyloid precursor protein (APP) mutant mice 

folate deficiency renders hippocampal CA3 neurons in APP mutant mice vulnerable to death by 

a mechanism that does not involve increased amyloid β-peptide production or deposition. 

 Only two studies examined the effects of B vitamins on the expression or function of ADrelated genes. The series of animal experiments showed that while apolipoprotein E (ApoE)-

deficient mice are less capable of buffering oxidative challenge in the central nervous system 

than are normal mice, the genetic deficiency could be alleviated with folate repletion. The results 

from the in vitro study demonstrated that presenilin-1 could be induced by folate and vitamin 

B12 deprivation. The other genes involved in APP processing and APP itself seemed to be 

independent of folate and vitamin B12 deprivation. 

 A study found that selective transport of pyruvate across the BBB was not functioning in a 

normal fashion in thiamine-deficient rats; BBB damage seen in later stages corresponded to 

damage seen from cold-injury edema and other models of cerebral edema. The leakage across 

the BBB appears to be predominantly through the mechanism of pinocytosis (introduction of 

fluids into a cell by invagination of the cell membrane, followed by formation of vesicles within 

the cells), not disruption of interendothelial junctions. Another study showed that folate is 

protective against homocysteine-induced cerebrovascular damage. 

 Overall, research has shown that there were negative effects of thiamine and folate deficiency 

or deprivation on animals’ clinical status and/or histopathology, although not all deficient 

animals had worse performance in neurocognitive tests. Studies have found some positive effects 

of the supplementations of B6, B12, and folate on animal’s performance in neurocognitive tests, 

but studies did not show a dose-response relationship. Only folate deficiency was examined in 

animal models of AD or PD, and the results showed a synergistic effect with PD or AD 

pathology. Folate appears to protect against oxidative damage associated with ApoE deficiency. 

Folate and B12 deficiency also induce presenilin-1, but do not appear to affect APP. Thiamine 

(vitamin B1) is required for active transport of pyruvate across the BBB and maintaining 

integrity and normal permeability of BBB and folate is protective against homocysteine-induced 

cerebrovascular damage. 

B Vitamin Intervention Trials 

Vitamin B1. Five studies – three randomized controlled trials (RCTs), one non-randomized 

comparative trial (N-RCT), and one uncontrolled cohort study – on the effect of thiamine 
133

intervention among people with either probable or possible AD were heterogeneous in their 

outcomes. Most found improvements in cognitive function or a slowed rate of deterioration using 

some measures of cognitive testing, either compared to control or in uncontrolled studies. 

However, either no difference between treatment and control or no improvement with thiamine 

was found in all studies with other measures of cognitive function. Only the uncontrolled cohort 

study reported blood levels of thiamine before intervention and after intervention, and the study 

included AD subjects with normal mean levels of thiamine. 

Vitamin B2. No prospective trial has evaluated the effect of B2 treatment on neurocognitive 

function. 

Vitamin B6. Only two RCTs of cognitively intact populations investigated the effect of B6 

intervention on cognitive function. Participants had B6 levels within normal range in both trials. 

With treatment, a significant improvement was found with one cognitive function test. It is also 

unclear whether the changes with treatment were significantly different than changes in the 

control arm. No other significant change was reported in the studies. 

Vitamin B12. Five RCTs, one non-randomized comparative trial, and seven cohort studies 

assessed the effect of B12 intervention on cognitive function in humans. Two RCTs, one nonrandomized comparative trial, and four cohort studies recruited participants with low B12 levels, 

while the rest of the studies assessed individuals with normal B12 levels. There was a large 

degree of heterogeneity in populations, levels of B12 deficiency, dose, route of administration, 

and cognitive function assessment instruments. Although several of the studies showed some 

improvement in cognitive function, few reached statistical significance. Among studies that 

assessed similar populations after implementing the same tests, results were frequently 

conflicting. Several cohort studies revealed significant improvement while fewer cohorts 

reported a significant decline in scores for cognitive function. However, the interpretation of 

these studies is difficult because they analyzed subjects with variable courses of dementia over 

time, without comparing to control groups. Vitamin B12 was given intramuscularly in the only 

RCT that found a significant effect in the treatment group compared with the controls. Similarly, 

only cohort studies that used intravenous or intramuscular vitamin B12 reported a significant 

effect on cognitive function scores. However, given the lack of data directly comparing oral and 

injected routes of vitamin B12 and the paucity of controlled trials limits any conclusions 

regarding the utility of different routes of administration. Some indirect evidence showed that 

demented or cognitively impaired patients with short duration of treatment for dementia or short 

disease duration might benefit more than patients with treatment or disease of longer duration if 

they use B12. 

Folate. Five studies (three RCTs and two uncontrolled cohort studies) reported data on the effect 

of folate intervention among normal people or those with dementia, cognitive impairment, or PD. 

One RCT among subjects with dementia and normal folate levels found worse 

neuropsychological scores in the folate treatment group among subjects with dementia. Two 

other studies – one RCT and one uncontrolled cohort study – found statistically significant 

improvement in the folate treatment compared with placebo group among demented, cognitive 

impaired, and normal subjects. The study of patients with PD found no therapeutic benefit. Three 
134

studies reported blood folate levels before intervention; of which only two studies (one RCT and 

one uncontrolled cohort study) included patients with low folate levels. 

Combination of B vitamins. Six studies (three RCTs and three uncontrolled cohort studies) 

assessed the effects of a combination of B vitamins as interventions on cognitive function. All 

used different daily doses of various B vitamins including folate, B6, and B12. Five of the six 

studies found no significant change in cognitive function after combination B vitamin 

supplementation. Only one of the uncontrolled cohort studies found a significant, large benefit. 

Only one RCT assessed the effects of combined vitamin intervention on patients with low blood 

folate levels; other studies included patients with normal mean blood vitamin levels. 

Overall. There is weak evidence of a possible benefit of thiamine supplementation in people 

with AD. There is also weak, and inconsistent, evidence that treatment with injected vitamin B12 

is of benefit among those with recent diagnoses of AD or cognitive impairment, particularly if 

low B12 levels have been documented. The effect of treatment with both B6 and folate is 

unclear. A single study of B6 found possible improvement with treatment. While studies of 

folate treatment among demented, cognitive impaired, and normal subjects did find an 

improvement in cognitive function with folate, one study of patients with dementia did find a 

worsening on neuropsychological testing with folate compared to controls. Combination 

treatments with folate, B6, and oral B12 overall were of no benefit. A single study found no 

benefit of folate treatment for PD. No studies evaluated vitamin B2. 

B Vitamin Dietary Intake Studies. Five longitudinal studies and five cross-sectional studies 

examined the association between the dietary intake levels of B vitamins and cognitive function 

or the risk of age-related neurodegenerative diseases. No significant associations were found 

between dietary intakes of B6 or B12 and PD, AD, cognitive functioning, or cognitive decline 

across three studies. One additional study found higher dietary intakes of B6, B12, and folate 

were associated with improvements in some, but not all, cognitive function measures. In three 

separate studies, folate intake was not associated with PD or AD; however, in one study, higher 

folate intake from food sources and/or supplements was associated with a faster rate of cognitive 

decline after adjusting for multiple risk factors. Among the five studies cross-sectional studies, 

only two found any significant associations. One found that subjects with low intake of vitamins 

B1, B2, B6, and folate, but not B12, scored significantly worse on verbal memory than those 

with relatively high intake levels. Another also found an association between vitamin B2 intake 

and cognitive testing in women, but not men. No association between dietary intake of B12 and 

cognitive function or diagnosis of AD was found in all five cross-sectional studies. 

B Vitamin Status Studies 

Vitamin B1. Overall, eight cross-sectional studies evaluated levels of thiamine among AD, 

cognitively impaired, and PD patients. Thiamine levels were measured in plasma, cerebrospinal 

fluid (CSF) or autopsied brain. Three studies reported significantly reduced mean thiamine levels 

in the plasma or brain among AD subjects, and one reported a similar reduction in mean levels of 

thiamine among PD subjects. However, none of the studies that showed significant results 

adjusted for potential confounders. The remaining four studies found no differences among the 

investigated groups. 
135

Vitamin B2. Two cross-sectional studies assessed B2 levels among AD or PD and control 

groups, which included mixed dementia, vascular dementia, and normal subjects. The study of 

AD subjects reported no significant difference in riboflavin levels among the groups. The study 

comparing PD to dementia without stroke found lower B2 levels among those with PD. Neither 

study adjusted for confounders. 

Vitamin B6. Ten studies of various designs examined the potential association of B6 serum 

levels with the diagnosis of dementia or cognitive impairment, or cognitive function. Only one 

longitudinal cohort study showed a significant correlation between higher levels of vitamin B6 at 

baseline in cognitively intact subjects and better performance in the figure copying test after 3 

years of follow-up. No other significant correlations were found. 

Vitamin B12. Thirty-three studies investigated a potential association between serum B12 levels 

and cognitive function or diagnosis of several types of dementia and cognitive impairment. Most 

of the studies focused on AD. Thresholds for B12 deficiency varied across studies. Based on the 

few longitudinal studies, serum B12 levels are not associated with the risk for developing AD or 

dementia. However, two of the longitudinal studies reported a correlation between serum vitamin 

B12 levels at baseline and cognitive function status at the end of follow-up among cognitively 

intact subjects. Other studies that implemented a cognitive function assessment instrument did 

not support an association between serum B12 levels and cognitive function. Among crosssectional studies, there was a trend for B12 serum levels to be lower in patients with AD or other 

types of dementia, which in certain studies reached statistical significance. However, this trend 

was not consistent. An inverse correlation between B12 levels and duration of AD was reported 

by one study. Overall though, there is limited evidence for populations with PD, AD, and 

vascular dementia. Potential factors such as genetic mutations, or disease severity that may affect 

B12 levels were analyzed by few studies without revealing any consistent effect. 

Folate. Thirty four studies examined folate levels assessed in the red blood cells, plasma, serum, 

CSF, and blood. Fifteen studies examined the association between folate levels and future 

cognitive function; ten of the studies were longitudinal and the remainders were case-control or 

cross-sectional with single time-point analyses. All the studies consistently reported either lower 

mean folate levels or higher prevalence of folate deficiency among subjects with AD and/or 

cognitive impairment. Overall, one-third of the studies adjusted for possible confounders. 

Among studies that assessed the association between folate levels and cognitive function, four 

longitudinal studies and one case-control study reported a statistically significant association 

between lowest quantile of folate level and cognitive decline after adjusting for possible 

confounders. One other case-control study reported significant inverse association of folate with 

cognitive function. Two studies reported no difference in folate levels between subjects with PD 

and controls. 

Overall. The association between thiamine status and age-related cognitive disorders is unclear. 

Half the studies found no associations and half found lower levels among AD, cognitively 

impaired, and PD patients. However, none of these studies could differentiate between cause 

(low thiamine levels resulting in disease) and effect (changes due to disease, including nutritional 

intake, resulting in low thiamine levels). The studies also failed to adjust for potential 

confounders. The cross-sectional studies of B2 found no association with diagnosis of AD, but 
136

low levels among people with PD. The large majority of B6 studies found no association 

between B6 status and the diagnosis of dementia or cognitive impairment, or cognitive function. 

A large number of studies have evaluated both B12 and folate status. The better, longitudinal 

studies of B12 failed to find an association with diagnosis or severity of disease. While trends 

toward lower B12 levels among people with AD were found in cross-sectional studies, these 

associations were not consistent and proper adjustment for potential confounders was rarely 

performed. Both the longitudinal and case-control studies of folate status mostly reported an 

association between low folate levels (defined differently in different studies) and future 

diagnosis of AD and/or cognitive impairment. No association with PD was found. 

Adverse Events. Among the 39 articles reporting on 43 cohorts of subjects taking B vitamin 

supplements, only 10 reported any information on adverse events. Of these, only two reported 

that any adverse events occurred. Thiamine was tolerated well in four studies; although initially 

high doses caused mild gastrointestinal complaints. One of three folate studies reported mild, 

possibly neurological complaints, that may have been associated with the subjects’ PD. No 

adverse events were noted in one B12 study and in two combination B vitamin studies. No 

studies reported adverse events for B2 or B6. 

Berries 

 This report includes evaluations of whole berries, berry extracts, and constituents of berries 

that were derived directly from the fruits. The following berries were included: bilberry, black 

raspberry, blackberry, blueberry, boysenberry, cranberry, currants, gooseberry, lingonberry, 

marionberry, raspberry, and strawberry. However, evidence was found for only bilberries, 

blueberries, boysenberries, cranberries, currants, gooseberries, and strawberries. 

Constituents of Berries. Only a limited number of the numerous constituents in berries have 

been examined separately from the rest of the fruit. These include tannins, anthocyanins and 

phenolics, from various berries. 

Mechanisms of Action. All studies related to mechanisms of action of berry constituents (or 

whole berries) have been performed in animal or in vitro models. Among 18 animal or in vitro 

studies (with 19 experiments) investigating berries and neurocognitive function or processes, 

four studies examined the effects of specific berry constituents on animal performance in 

neurocognitive testing or on brain biochemistry. The remaining 14 studies (with 15 experiments) 

used berry extracts that supplemented normal diet or added to in vitro media. 

Effects of the constituents in berries. One study showed that intraperitoneally injected bilberry 

extract containing anthocyanins significantly increased rat brain uptake of triiodothyronine (T3). 

A second study measured the concentrations of 18 plant tannins, including blueberry, red currant, 

and gooseberry, generally inhibit brain protein kinase C to a similar degree; although the 

biological significance in live animals of this in vitro inhibition is unknown. The third study 

demonstrated that that the anthocyanins in blueberry extracts were able to cross the BBB and the 

number of the total anthocyanins measured in the brain is associated with rats’ learning 

performance. The fourth study compared the effects of specific berry constituents on 

neurocognitive outcomes. Rat performance suggested that there is a range of effectiveness 

associated with the different berry extracts. However, it does not appear that the anthocyanin 
137

component is solely responsible for these improvements. Of note, both the third and fourth 

studies found no significant effect on rat performance in the Morris Water Maze compared berry 

to control groups. 

Effects of berry extract supplementation. Berry extracts were used to supplement animals’ diet 

or added to in vitro study media in 14 studies with 15 experiments that examined animal 

performance in neurocognitive testing or brain biochemistry or histology. Of these, two studies 

used specific animal or in vitro models of AD The remaining 13 studies used adult or aged rat 

models. Most studies were of good quality. All of these studies were from the same group of 

investigators. 

 Only strawberry and blueberry extracts were used to examine the effects of extract 

supplementation on animal performance in neurocognitive testing or brain biochemistry or 

histology using a normal-aging rat model. Blueberry and strawberry extract supplementation 

showed positive or protective effects on almost all biochemical markers and histology findings 

examined in the rat brain, although only some of the neurocognitive tests and psychomotor 

functions were significantly improved in these berry-extract-fed rats. 

 Only two studies used models of AD to examine the effects of various berry extracts. The 

results suggested that it may be possible to reduce both the deleterious effects of dopamine and 

the putative toxic effects of amyloid β via various berry extracts as shown in the in vitro study. 

Results from the animal study that used mice transgenic for amyloid precursor protein and 

presenilin-1 mutations to model human AD showed that the blueberry extract supplementation 

seemed to have prevented the deficits in Y-maze performance seen in the transgenic animals fed 

the control diets, although it did not affect amyloid β deposits. 

Human Studies. Only one study evaluated any association between berry (or berry constituent) 

intake and neurocognitive function. A case-control study of patients with PD, their siblings, and 

their spouses found that the preference to consume blueberries or strawberries was not 

statistically significantly associated with presence of PD 

Adverse Effects. The single human study of berry consumption was retrospective, therefore no 

study provided data regarding adverse events from berries in the setting of neurocognitive 

disorders. 

Limitations 

 An important limitation to the review of age-related neurocognitive disorders is that only 

scant research in either humans or animal or in vitro models has been performed related to 

movement disorders and motor symptom degeneration related to PD and associated diseases. 

Animal and In Vitro Studies 

 Rodents are the animals most commonly used to model human cognitive dysfunction or agerelated cognitive deficits, but many of the behavioral paradigms employed for evaluation of 

rodent cognitive abilities or functions are fairly different from those generally assessed in 

humans.193 Furthermore, many confounding factors, such as housing conditions, strain, gender, 

diet, biological rhythms, “stress,” and route of drug administration can affect test data 
138

significantly.194 There remain substantial controversies surrounding the research findings from 

animal models of cognitive dysfunction. In particular there is no sound empirical basis for 

making cross-species generalizations about the neural structures that mediate performance in 

tasks used to assess memory.193 This is most relevant when comparing animal models to human 

diseases. In addition, the measured outcomes in animal models are indirect measures of the 

psychological construct in any test of cognitive function. Therefore, the measures of animals’ 

performance in “cognitive tests” are generally not direct or pure measures of cognitive function. 

For example, age-related deficits in the Morris Water Maze may not be restricted to learning and 

memory, but may also include deficits in attention, the ability to process spatial information, and 

the ability to develop efficient spatial search strategies.187 It is clear that methodology and 

procedures of animal models of human cognitive dysfunction are very complex. It is important to 

avoid simplistic overgeneralizations and inappropriate interpretations of data from animal 

models of human cognitive dysfunction or age-related cognitive deficits, although this research 

has generated valuable information about the possible neurobiological basis of the cognitive 

deficits. 

 There are a number of limitations specific to our review of the B vitamin and berry literature. 

The large majority of studies measured performance in otherwise healthy rodents who were 

made severely deficient in B vitamins. While these studies might elucidate which B vitamins are 

required for maintenance of brain function, they rarely addressed the question of the actual 

mechanism of action of the B vitamins. Furthermore, the link between severe vitamin deficiency 

in normal rodents and the effect of relative vitamin deficiency on human age-related 

neurocognitive disorders is generally tenuous. Particularly in the case of thiamine deficiency, 

which is known to result in Wernicke’s encephalopathy, the association with AD (or PD) is 

difficult to ascertain. Studies that linked vitamin deficiencies, vitamin supplementation, or berry 

supplementation to specific mechanisms of action on nervous tissue were rare and generally 

provide only a patchy picture of their potential effects. 

 A major limitation to the data on the potential effects of berries on neurocognitive function is 

that almost all the studies have been performed in a single laboratory. Replication or similar 

studies performed by independent groups are necessary before firm conclusions about the 

putative effects of berries can be made. The constituents in berries that may be responsible for 

the observed effects on neurocognitive function have yet to be found and the possible 

mechanisms of action have yet to be fully elucidated. 

 There remains considerable disagreement about the most meaningful way to assess study 

quality in human studies, with few analyses attempting to validate specific quality measures. The 

assessment of study quality in animal and in vitro studies, though, is still in its infancy. No 

studies have been reported that quantitatively assess the factors that may bias these studies. 

However, it is clear that improved study design and reporting are necessary. 

Human Studies 

 Only a single, retrospective, human study of berries and PD has been reported. Thus it is 

clearly premature to assess the association between consumption of berries or berry constituents 

and age-related neurocognitive disorders. 

 Among the human B vitamin studies, the majority were of poor quality. The majority of data 

come from cross-sectional studies, most of which provided only univariate analyses. Even under 

the best of circumstances cross-sectional studies cannot differentiate between cause and effect. 
139

Thus any associations between B vitamin status and either diagnosis of AD, PD or dementia, or 

severity of disease may equally be caused by changes in nutrition due to the diseases as by 

effects of B vitamins on brain function. Many of the associations may also be spurious, since 

studies rarely attempted to correct for potential confounders such as nutrition status, 

inflammation status (e.g., homocysteine level), diet, duration of disease, age, sex, genotype, and 

other factors. 

 Among the trials of B vitamin supplementation, a large number were either non-randomized 

comparative trials or non-controlled studies of various designs. These studies are clearly 

deficient for an adequate assessment of the potential value of B vitamin supplementation. Even 

among the RCTs the quality of the studies was often poor due to incomplete reporting of 

methodology and results, lack of blinding, small sample size, short duration, and various other 

factors. 

 All the B vitamin studies as a group also suffered from lack of standardization of B vitamin 

measurement technique, of tissue source (blood, plasma, serum, red blood cell, and cerebrospinal 

fluid), of normal ranges for B vitamins, of definitions of diagnoses of various dementias, and of 

tests of cognitive function. In addition, on the order of 50 different tests or subtests were used 

across the studies. These tests measure different or overlapping domains of cognitive function. 

Comparisons across studies was thus very difficult. There is also scant evidence regarding the 

effect of B vitamins on PD. 

Future Research 

Human Studies 

 Due to either the limited amount of available data or the poor quality of the bulk of the 

research to date, future well-performed, well-analyzed, large, prospective studies would be 

necessary to address all the questions posed regarding the effects and associations between either 

B vitamins or berries and age-related neurocognitive function. However, standardization is 

clearly needed both in the areas of vitamin research and in neurocognitive disease. Assuming 

that additional studies are deemed worthwhile by the research community, these future studies 

should use only well-verified and commonly used measurement techniques for B vitamin status, 

and where no standardization has yet been agreed upon, this should be a priority. This may 

require additional research to verify the value of measurement tools for neurocognitive function. 

Future studies should also use only well-established diagnostic criteria for neurocognitive 

disorders and should use only measures of cognitive function that have been verified and are 

commonly used. Studies that use non-standard diagnostic definitions or neurocognitive tests are 

of limited value to clinicians, policy makers, and other researchers. 

 Common to most bodies of evidence regarding medical fields, better quality, well-reported,

larger and longer duration studies are needed to address the questions of interest. We strongly 

recommend that all future randomized trials – including those of B vitamins and potentially of 

berries or berry supplements– use the CONSORT statement as a guide to reporting 

(www.consort-statement.org).195,196 This will not only improve the readers’ understanding of the 

trials, but should also improve the quality of published studies. The value of non-randomized, 

and particularly non-controlled, trials is limited. 

 Further cross-sectional studies evaluating the association between B vitamin status and either 

diagnosis or severity of disease, with few exceptions are of very limited value. Only those that 
140

could include additional data that would give an indication as to cause and effect might be 

warranted. Additional longitudinal studies are needed to address the questions of the effect of B 

vitamin status on development of neurocognitive disorders or on the severity of disease. These 

should either be well-conducted dietary studies using well-established food frequency 

questionnaire techniques or well-powered, sufficiently analyzed long-term prospective studies. 

All of these studies of correlations must use appropriate statistical tools, including adjustment for 

potential confounders and investigation of interactions and sub-groups. 

 Regarding evaluation of berries and berry constituents, if the animal and in vitro research is 

deemed to be of sufficient merit to warrant a human study, we would strongly recommend that 

these studies be more of practical than theoretical value. Trials of extreme diets (i.e., of large 

daily quantities of berries) or of supplementation with large quantities of berry constituents 

would not be practical for anyone but research subjects. Even though these studies might help to 

explain mechanisms of action, they would fail to provide reasonable guidance for those seeking 

to either prevent or slow neurocognitive decline. Both dietary and supplementation studies 

should be of doses that a normal person can both easily incorporate into their lifestyle and afford. 

Animal and In Vitro Studies 

 Animal or in vitro models are especially suitable for investigating the mechanisms of actions 

of factors that might affect the aging process and the accompanying neurodegenerative changes 

in human, because the contribution of genetic and environmental factors to the aging process can 

be strictly controlled in animal or in vitro studies. 

 Several questions of interest will continue to be difficult to address from human studies given 

ethical and practical limitations. Topics of particular interest that may be more suitable to animal 

research include sorting out the independent effects of elevated homocysteine and of low 

B vitamin levels and/or intake, and clarifying the relative harm of B vitamin deficiency (or 

benefit of B vitamin supplementation) in different stages of health or neurocognitive disease. 

Several large observational studies in humans have attempted to address the interaction with 

homocysteine, however, without the ability to closely control homocysteine and B vitamin levels 

(or intake) it is unlikely that human studies will definitively answer this question. In addition, for 

practical reasons, it has been very difficult and thus rare that human studies are able to control 

sufficient factors to allow full analysis of B vitamin status and neurocognitive status. 

 Unfortunately many of the tasks or tests available to assess the processes underlying the ageassociated deterioration of learning and memory have not been validated. Some insights for 

future aging research using animal or in vitro models were described in details 

elsewhere.193,194,197 Here we summarize their recommendations for future research of ageassociated cognitive deficits or normal aging: 

1. Identify learning and memory tests that are suitable for longitudinal investigations. 

2. Replicate all test conditions. 

3. Select behavioral or functional models suitable for testing two or more species. This will 

enable the comparison of data across species and encourage inter-species comparative 

studies. 

4. Select two or more models, each thought to measure the same cognitive process. This 

will enable evaluation of the concurrent validities of those models. 

5. Measure as many different aspects of performance as possible in as great a resolution as 

possible. 
141

6. Measure learning/memory as a function of degradation of critical stimuli and/or 

increasing task difficulty. This will enable estimation of the construct validity of the 

model. 

7. Measure mnemonic and non-mnemonic (such as attention) performance in the same 

animal in the same test session. This allows a comparative approach to assess the 

cognitive processes in animals that appear to be activated in humans when performing 

cognitive tests. 

8. Take into account the effects of individual animal variability. Ideally, use a single-subject 

repeated measures design. 

 In particular, regarding future studies of berries and berry constituents, future research should 

elucidate the specific constituents that might be responsible for the observed effects on 

neurocognitive function. For both berry and B vitamin studies, when possible, experiments 

should evaluate both the specific mechanisms of action and neurocognitive function, allowing a 

correlation to be made between the two. However, the need for future animal and in vitro studies 

to evaluate putative mechanisms of action should be assessed largely based on whether clinical 

benefits of B vitamins and or berries are found in human trials. 

143

References and Included Studies 

References 

1. Cowan WM, Kandel ER. Prospects for neurology 

and psychiatry. JAMA 2001; 285(5):594-600. 

2. Martin JB. Molecular basis of the 

neurodegenerative disorders. N Engl J Med 1999; 

340(25):1970-1980. 

3. Nussbaum RL, Ellis CE. Alzheimer's disease and 

Parkinson's disease. N Engl J Med 2003; 

348(14):1356-1364. 

4. Hy LX, Keller DM. Prevalence of AD among 

whites: a summary by levels of severity. 

Neurology 2000; 55(2):198-204. 

5. Blacker D, Albert MS, Bassett SS et al. Reliability 

and validity of NINCDS-ADRDA criteria for 

Alzheimer's disease. The National Institute of 

Mental Health Genetics Initiative. Arch Neurol 

1994; 51(12):1198-1204. 

6. Lang AE, Lozano AM. Parkinson's disease. First 

of two parts. N Engl J Med 1998; 339(15):1044-

1053. 

7. Tanner CM, Goldman SM. Epidemiology of 

Parkinson's disease. Neurol Clin 1996; 14(2):317-

335. 

8. Przedborski S, Vila M, Jackson-Lewis V. 

Neurodegeneration: what is it and where are we? J 

Clin Invest 2003; 111(1):3-10. 

9. Herrmann N. Cognitive pharmacotherapy of 

Alzheimer's disease and other dementias. Can J 

Psychiatry 2002; 47(8):715-722. 

10. Hardy J. Amyloid, the presenilins and Alzheimer's 

disease. Trends Neurosci 1997; 20(4):154-159. 

11. Mattson MP, Chan SL, Duan W. Modification of 

brain aging and neurodegenerative disorders by 

genes, diet, and behavior. Physiol Rev 2002; 

82(3):637-672. 

12. Ibanez P, Bonnet AM, Debarges B et al. Causal 

relation between alpha-synuclein gene duplication 

and familial Parkinson's disease. Lancet 2004; 

364(9440):1169-1171. 

13. Meydani M. Antioxidants and cognitive function. 

Nutr Rev 2001; 59(8 Pt 2):S75-S80. 

14. Floyd RA. Antioxidants, oxidative stress, and 

degenerative neurological disorders. Proc Soc Exp 

Biol Med 1999; 222(3):236-245. 

15. Durany N, Munch G, Michel T, Riederer P. 

Investigations on oxidative stress and 

therapeutical implications in dementia. Eur Arch 

Psychiatry Clin Neurosci 1999; 249(Suppl 3):68-

73. 

16. Behl C. Alzheimer's disease and oxidative stress: 

implications for novel therapeutic approaches. 

Prog Neurobiol 1999; 57(3):301-323. 

17. Butterfield DA, Howard B, Yatin S et al. 

Elevated oxidative stress in models of normal 

brain aging and Alzheimer's disease. Life Sci 

1999; 65(18-19):1883-1892. 

18. Seshadri S, Beiser A, Selhub J et al. Plasma 

homocysteine as a risk factor for dementia and 

Alzheimer's disease. N Engl J Med 2002; 

346(7):476-483. 

19. Wardlaw GM, Kessel M. The Water-Soluble 

Vitamins. Perspectivs in Nutrition - 5th ed. New 

York: McGraw-Hill, 2002: 364-417. 

20. Rodriguez-Martin JL, Lopez-Arrieta JM, 

Qizilbash N. Thiamine for Alzheimer's disease. 

Cochrane Database Syst Rev 

2000;(2):CD001498. 

21. Rodriguez-Martin JL, Qizilbash N, LopezArrieta JM. Thiamine for Alzheimer's disease. 

Cochrane Database Syst Rev 

2001;(2):CD001498. 

22. Kretsch MJ, Sauberlich HE, Newbrun E. 

Electroencephalographic changes and 

periodontal status during short-term vitamin B-6 

depletion of young, nonpregnant women. Am J 

Clin Nutr 1991; 53(5):1266-1274. 

23. Canham JE, Baker EM, Harding RS, Sauberlich 

HE, Plough IC. Dietary protein--its relationship 

to vitamin B6 requirements and function. Ann 

NY Acad Sci 1969; 166(1):16-29. 

24. Riggs KM, Spiro A, III, Tucker K, Rush D. 

Relations of vitamin B-12, vitamin B-6, folate, 

and homocysteine to cognitive performance in 

the Normative Aging Study. Am J Clin Nutr 

1996; 63(3):306-314. 
144

25. Wang HX, Wahlin A, Basun H et al. Vitamin 

B(12) and folate in relation to the development of 

Alzheimer's disease. Neurology 2001; 56(9):1188-

1194. 

26. Duan W, Ladenheim B, Cutler RG et al. Dietary 

folate deficiency and elevated homocysteine levels 

endanger dopaminergic neurons in models of 

Parkinson's disease. J Neurochem 2002; 

80(1):101-110. 

27. Kruman II, Kumaravel TS, Lohani A et al. Folic 

acid deficiency and homocysteine impair DNA 

repair in hippocampal neurons and sensitize them 

to amyloid toxicity in experimental models of 

Alzheimer's disease. J Neurosci 2002; 22(5):1752-

1762. 

28. Hyson D. The health benefits of fruits and 

vegetables: A review of the literature from 1999 to 

2001. 2002. Produce for Better Health Foundation. 

29. Casadesus G, Shukitt-Hale B, Joseph JA. 

Qualitative versus quantitative caloric intake: are 

they equivalent paths to successful aging? 

Neurobiol Aging 2002; 23(5):747-769. 

30. Youdim KA, Joseph JA. A possible emerging role 

of phytochemicals in improving age-related 

neurological dysfunctions: a multiplicity of 

effects. Free Radic Biol Med 2001; 30(6):583-594. 

31. Kalat JW, Rozin P. "Learned safety" as a 

mechanism in long-delay taste-aversion learning 

in rats. J Comp Physiol Psychol 1973; 83(2):198-

207. 

32. Balk EM, Bonis PA, Moskowitz H et al. 

Correlation of quality measures with estimates of 

treatment effect in meta-analyses of randomized 

controlled trials. JAMA 2002; 287(22):2973-2982. 

33. National Kidney Foundation. K/DOQI clinical 

practice guidelines for chronic kidney disease: 

evaluation, classification, and stratification. 

Kidney Disease Outcome Quality Initiative. Am J 

Kidney Dis 2002; 39(2:Suppl 2):Suppl-246. 

34. Ciccia RM, Langlais PJ. An examination of the 

synergistic interaction of ethanol and thiamine 

deficiency in the development of neurological 

signs and long-term cognitive and memory 

impairments. Alcohol Clin Exp Res 2000; 

24(5):622-634. 

35. Jolicoeur FB, Rondeau DB, Barbeau A, Wayner 

MJ. Comparison of neurobehavioral effects 

induced by various experimental models of ataxia 

in the rat. Neurobehav Toxicol 1979; 1(S1):175-

178. 

36. Jolicoeur FB, Rondeau DB, Hamel E, 

Butterworth RF, Barbeau A. Measurement of 

ataxia and related neurological signs in the 

laboratory rat. Can J Neurol Sci 1979; 6(2):209-

215. 

37. Masuda Y, Kokubu T, Yamashita M, Ikeda H, 

Inoue S. EGG phosphatidylcholine combined 

with vitamin B12 improved memory impairment 

following lesioning of nucleus basalis in rats. 

Life Sci 1998; 62(9):813-822. 

38. Terasawa M, Nakahara T, Tsukada N, Sugawara 

A, Itokawa Y. The relationship between thiamine 

deficiency and performance of a learning task in 

rats. Metabol Brain Dis 1999; 14(3):137-148. 

39. Zimitat C, Kril J, Harper CG, Nixon PF. 

Progression of neurological disease in thiamindeficient rats is enhanced by ethanol. Alcohol 

1990; 7(6):493-501. 

40. Kim JM, Lee H, Chang N. 

Hyperhomocysteinemia due to short-term folate 

deprivation is related to electron microscopic 

changes in the rat brain. J Nutr 2002; 

132(11):3418-3421. 

41. Driskell JA, Strickland LA, Poon CH, Foshee 

DP. The vitamin B6 requirement of the male rat 

as determined by behavioral patterns, brain 

pyridoxal phosphate and nucleic acid 

composition and erythrocyte alanine 

aminotransferase activity. J Nutr 1973; 

103(5):670-680. 

42. Tunnicliff G, Wimer RE, Roberts E. Pyridoxine 

dietary levels and open-field activity of inbred 

mice. Brain Res 1972; 42(1):234-238. 

43. Collins GH, Converse WK. Cerebellar 

degeneration in thiamine-deficient rats. Am J 

Pathol 1970; 58(2):219-233. 

44. Ezer E, Szporny L. Tape test as a simple new 

method for the study of compounds increasing 

the problem-solving ability of the rat. 

Psychopharmacology 1976; 48(1):97-99. 

45. Gospe SM, Jr., Gietzen DW, Summers PJ et al. 

Behavioral and neurochemical changes in folatedeficient mice. Physiol Behav 1995; 58(5):935-

941. 

46. Guilarte TR, Miceli RC, Moran TH. 

Developmental effects of vitamin B-6 restriction 

on the locomotor behavior of rats. Brain Res 

Bull 1991; 26(6):857-861. 
145

47. Nakagawasai O, Tadano T, Niijima F, TanNo K, 

Kisara K. Immunohistochemical estimation of rat 

brain somatostatin on avoidance learning 

impairment induced by thiamine deficiency. Brain 

Res Bull 2000; 51(1):47-55. 

48. Robertson DM, Wasan SM, Skinner DB. 

Ultrastructural features of early brain stem lesions 

of thiamine-deficient rats. Am J Pathol 1968; 

52(5):1081-1097. 

49. Sasaki H, Matsuzaki Y, Meguro K et al. Vitamin 

B12 improves cognitive disturbance in rodents fed 

a choline-deficient diet. Pharmacol Biochem 

Behav 1992; 43(2):635-639. 

50. Sasaki H, Meguro K, Matsuzaki Y et al. Effect of 

nicotine on cognitive disturbance in animals with 

acetylcholine deficient brain. Jpn J Psychopharm 

1993; 13(3):143-147. 

51. Stewart CN, Coursin DB, Bhagavan HN. 

Avoidance behavior in vitamin B-6 deficient rats. 

J Nutr 1975; 105(11):1363-1370. 

52. Shea TB, Rogers E. Folate quenches oxidative 

damage in brains of apolipoprotein E-deficient 

mice: augmentation by vitamin E. Brain Res Mol 

Brain Res 2002; 108(1-2):1-6. 

53. Shea TB, Rogers E, Ashline D, Ortiz D, Sheu MS. 

Apolipoprotein E deficiency promotes increased 

oxidative stress and compensatory increases in 

antioxidants in brain tissue. Free Radic Biol Med 

2002; 33(8):1115-1120. 

54. Shea TB, Rogers E, Ashline D et al. Vitamin E 

deficiency does not induce compensatory 

antioxidant increases in central nervous system 

tissue of apolipoprotein E-deficient mice. J 

Alzheimers Dis 2003; 5(1):9-14. 

55. Fuso A, Seminara L, Cavallaro RA, D'Anselmi F, 

Scarpa S. S-adenosylmethionine/homocysteine 

cycle alterations modify DNA methylation status 

with consequent deregulation of PS1 and BACE 

and beta-amyloid production. Mol Cell Neurosci 

2005; 28(1):195-204. 

56. Lee H, Kim HJ, Kim JM, Chang N. Effects of 

dietary folic acid supplementation on 

cerebrovascular endothelial dysfunction in rats 

with induced hyperhomocysteinemia. Brain Res 

2004; 996(2):139-147. 

57. Lee H, Kim JM, Kim HJ, Lee I, Chang N. Folic 

acid supplementation can reduce the endothelial 

damage in rat brain microvasculature due to 

hyperhomocysteinemia. J Nutr 2005; 135(3):544-

548. 

58. Warnock LG, Burkhalter VJ. Evidence of 

malfunctioning blood-brain barrier in 

experimental thiamine deficiency in rats. J Nutr 

1968; 94(2):256-260. 

59. Manz HJ, Robertson DM. Vascular permeability 

to horseradish peroxidase in brainstem lesions of 

thiamine-deficient rats. Am J Pathol 1972; 

66(3):565-576. 

60. Robertson DM, Manz HJ. Effect of thiamine 

deficiency on the competence of the blood-brain 

barrier to albumin labeled with fluorescent dyes. 

Am J Pathol 1971; 63(3):393-402. 

61. Blass JP, Gleason P, Brush D, DiPonte P, Thaler 

H. Thiamine and Alzheimer's disease. A pilot 

study. Arch Neurol 1988; 45(8):833-835. 

62. Meador K, Loring D, Nichols M et al. 

Preliminary findings of high-dose thiamine in 

dementia of Alzheimer's type. J Geriatr 

Psychiatry Neurol 1993; 6(4):222-229. 

63. Nolan KA, Black RS, Sheu KF, Langberg J, 

Blass JP. A trial of thiamine in Alzheimer's 

disease. Arch Neurol 1991; 48(1):81-83. 

64. Mimori Y, Katsuoka H, Nakamura S. Thiamine 

therapy in Alzheimer's disease. Metab Brain Dis 

1996; 11(1):89-94. 

65. Bryan J, Calvaresi E, Hughes D. Short-term 

folate, vitamin B-12 or vitamin B-6 

supplementation slightly affects memory 

performance but not mood in women of various 

ages. J Nutr 2002; 132(6):1345-1356. 

66. Deijen JB, van der Beek EJ, Orlebeke JF, van 

den BH. Vitamin B-6 supplementation in elderly 

men: effects on mood, memory, performance and 

mental effort. Psychopharmacology 1992; 

109(4):489-496. 

67. Abyad A. Prevalence of vitamin B12 deficiency 

among demented patients and cognitive recovery 

with cobalamin replacement. J Nutr Health 

Aging 2002; 6(4):254-260. 

68. Carmel R, Gott PS, Waters CH et al. The 

frequently low cobalamin levels in dementia 

usually signify treatable metabolic, neurologic 

and electrophysiologic abnormalities. Eur J 

Haematology 1995; 54(4):245-253. 

69. Hvas AM, Juul S, Lauritzen L, Nexo E, 

Ellegaard J. No effect of vitamin B-12 treatment 

on cognitive function and depression: a 

randomized placebo controlled study. J Affect 

Disord 2004; 81(3):269-273. 
146

70. Ikeda T, Yamamoto K, Takahashi K et al. 

Treatment of Alzheimer-type dementia with 

intravenous mecobalamin. Clin Ther 1992; 

14(3):426-437. 

71. Ito T, Yamadera H, Ito R et al. Effects of vitamin 

B12 on bright light on cognitive and sleep-wake 

rhythm in Alzheimer-type dementia. Psychiatry 

Clin Neurosci 2001; 55(3):281-282. 

72. Kral VA, Solyom L, Enesco H, Ledwidge B. 

Relationship of vitamin B12 and folic acid to 

memory function. Biol Psychiatry 1970; 2(1):19-

26. 

73. Kwok T, Tang C, Woo J et al. Randomized trial of 

the effect of supplementation on the cognitive 

function of older people with subnormal 

cobalamin levels. Int J Geriatr Psychiatry 1998; 

13(9):611-616. 

74. Martin DC, Francis J, Protetch J, Huff FJ. Time 

dependency of cognitive recovery with cobalamin 

replacement: report of a pilot study. J Am Geriatr 

Society 1992; 40(2):168-172. 

75. Mitsuyama Y, Kogoh H. Serum and cerebrospinal 

fluid vitamin B12 levels in demented patients with 

CH3-B12 treatment--preliminary study. Jpn J 

Psychiatry Neurol 1988; 42(1):65-71. 

76. Seal EC, Metz J, Flicker L, Melny J. A 

randomized, double-blind, placebo-controlled 

study of oral vitamin B12 supplementation in 

older patients with subnormal or borderline serum 

vitamin B12 concentrations. J Am Geriatr Soc 

2002; 50(1):146-151. 

77. Teunisse S, Bollen AE, van Gool WA, Walstra 

GJ. Dementia and subnormal levels of vitamin 

B12: effects of replacement therapy on dementia. J 

Neurol 1996; 243(7):522-529. 

78. van Asselt DZ, Pasman JW, van Lier HJ et al. 

Cobalamin supplementation improves cognitive 

and cerebral function in older, cobalamin-deficient 

persons. J Gerontol A Biol Sci Med Sci 2001; 

56(12):M775-M779. 

79. Sommer BR, Hoff AL, Costa M. Folic acid 

supplementation in dementia: a preliminary report. 

J Geriatr Psychiatry Neurol 2003; 16(3):156-159. 

80. Fioravanti M, Ferrario E, Massaia M et al. Low 

folate levels in the cognitive decline of elderly 

patients and the efficacy of folate as a treatment 

for improving memory deficits. Arch Gerontol and 

Geriatrics 1997; 26(1):1-13. 

81. McGeer PL, Zeldowicz L, McGeer EG. A 

clinical trial of folic acid in Parkinson's disease. 

Can Med Assoc J 1972; 106(2):145-146. 

82. Rapin JR, LePoncin M, Grebyl J. Blood folates 

deficiencies and cognitive functions in aging. 

Trends Biomed Gerontol 1988; 1:315-323. 

83. Clarke R, Harrison G, Richards S, Vital Trial 

Collaborative Group. Effect of vitamins and 

aspirin on markers of platelet activation, 

oxidative stress and homocysteine in people at 

high risk of dementia. J Intern Med 2003; 

254(1):67-75. 

84. Lewerin C, Matousek M, Steen G et al. 

Significant correlations of plasma homocysteine 

and serum methylmalonic acid with movement 

and cognitive performance in elderly subjects but 

no improvement from short-term vitamin 

therapy: a placebo-controlled randomized study. 

Am J Clin Nutr 2005; 81(5):1155-1162. 

85. Shaw DM, Macsweeney DA, Johnson AL et al. 

Folate and amine metabolites in senile dementia: 

a combined trial and biochemical study. Psychol 

Med 1971; 1(2):166-171. 

86. Aisen PS, Egelko S, Andrews H et al. A pilot 

study of vitamins to lower plasma homocysteine 

levels in Alzheimer disease. Am J Geriatr 

Psychiatry 2003; 11(2):246-249. 

87. Lehmann M, Regland B, Blennow K, Gottfries 

CG. Vitamin B12-B6-folate treatment improves 

blood-brain barrier function in patients with 

hyperhomocysteinaemia and mild cognitive 

impairment. Dement Geriatr Cogn Disord 2003; 

16(3):145-150. 

88. Nilsson K, Gustafson L, Hultberg B. 

Improvement of cognitive functions after 

cobalamin/folate supplementation in elderly 

patients with dementia and elevated plasma 

homocysteine. Int J Geriatr Psychiatry 2001; 

16(6):609-614. 

89. Chen H, Zhang SM, Schwarzschild MA et al. 

Folate intake and risk of Parkinson's disease. Am 

J Epidemiol 2004; 160(4):368-375. 

90. Deijen JB, Slump E, Wouters-Wesseling W et al. 

Nutritional intake and daily functioning of 

psychogeriatric nursing home residents. J Nutr 

Health Aging 2003; 7(4):242-246. 

91. Mizrahi EH, Jacobsen DW, Debanne SM et al. 

Plasma total homocysteine levels, dietary 

vitamin B6 and folate intake in AD and healthy 

aging. J Nutr Health Aging 2003; 7(3):160-165. 
147

92. Goodwin JS, Goodwin JM, Garry PJ. Association 

between nutritional status and cognitive 

functioning in a healthy elderly population. JAMA 

1983; 249(21):2917-2921. 

93. Lee L, Kang SA, Lee HO et al. Relationships 

between dietary intake and cognitive function 

level in Korean elderly people. Public Health 

2001; 115(2):133-138. 

94. Renvall MJ, Spindler AA, Ramsdell JW, Paskvan 

M. Nutritional status of free-living Alzheimer's 

patients. Am J Med Sci 1989; 298(1):20-27. 

95. Requejo AM, Ortega RM, Robles F et al. 

Influence of nutrition on cognitive function in a 

group of elderly, independently living people. Eur 

J Clin Nutr 2003; 57(Suppl 1):S54-S57. 

96. Tucker KL, Qiao N, Scott T, Rosenberg I, Spiro 

A, III. High homocysteine and low B vitamins 

predict cognitive decline in aging men: the 

Veterans Affairs Normative Aging Study. Am J 

Clin Nutr 2005; 82(3):627-635. 

97. Thompson FE, Byers T. Dietary assessment 

resource manual. J Nutr 1994; 124(11 

Suppl):2245S-2317S. 

98. Morris MC, Evans DA, Bienias JL et al. Dietary 

folate and vitamin B12 intake and cognitive 

decline among community-dwelling older persons. 

Arch Neurol 2005; 62(4):641-645. 

99. Assantachai P, Yamwong P, Chongsuphaijaisiddhi 

T. Relationships of vitamin B1, B12, folate and 

the cognitive ability of the Thai rural elderly. J 

Med Assoc Thai 1997; 80(11):700-705. 

100. Gold M, Chen MF, Johnson K. Plasma and red 

blood cell thiamine deficiency in patients with 

dementia of the Alzheimer's type. Arch Neurol 

1995; 52(11):1081-1086. 

101. Gold M, Hauser RA, Chen MF. Plasma thiamine 

deficiency associated with Alzheimer's disease but 

not Parkinson's disease. Metab Brain Dis 1998; 

13(1):43-53. 

102. Jimenez-Jimenez FJ, Molina JA, Hernanz A et al. 

Cerebrospinal fluid levels of thiamine in patients 

with Parkinson's disease. Neurosci Lett 1999; 

271(1):33-36. 

103. Mastrogiacoma F, Bettendorff L, Grisar T, Kish 

SJ. Brain thiamine, its phosphate esters, and its 

metabolizing enzymes in Alzheimer's disease. Ann 

Neurol 1996; 39(5):585-591. 

104. Molina JA, Jimenez-Jimenez FJ, Hernanz A et 

al. Cerebrospinal fluid levels of thiamine in 

patients with Alzheimer's disease. J Neural 

Transm 2002; 109(7-8):1035-1044. 

105. Snowdon DA, Tully CL, Smith CD, Riley KP, 

Markesbery WR. Serum folate and the severity 

of atrophy of the neocortex in Alzheimer disease: 

findings from the Nun study. Am J Clin Nutr 

2000; 71(4):993-998. 

106. Scileppi KP, Blass JP, Baker HG. Circulating 

vitamins in Alzheimer's dementia as compared 

with other dementias. J Am Geriatr Soc 1984; 

32(10):709-711. 

107. Coimbra CG, Junqueira VB. High doses of 

riboflavin and the elimination of dietary red meat 

promote the recovery of some motor functions in 

Parkinson's disease patients. Braz J Med Biol 

Res 2003; 36(10):1409-1417. 

108. Malaguarnera M, Ferri R, Bella R et al. 

Homocysteine, vitamin B12 and folate in 

vascular dementia and in Alzheimer disease. Clin 

Chem Lab Med 2004; 42(9):1032-1035. 

109. Miller JW, Green R, Mungas DM, Reed BR, 

Jagust WJ. Homocysteine, vitamin B6, and 

vascular disease in AD patients. Neurology 

2002; 58(10):1471-1475. 

110. Ravaglia G, Forti P, Maioli F et al. Elevated 

plasma homocysteine levels in centenarians are 

not associated with cognitive impairment. Mech 

Ageing Dev 2000; 121(1-3):251-261. 

111. Woitalla D, Kuhn W, Muller T. MTHFR C677T 

polymorphism, folic acid and 

hyperhomocysteinemia in levodopa treated 

patients with Parkinson's disease. J Neural 

Transm Suppl 2004;(68):15-20. 

112. Kado DM, Karlamangla AS, Huang MH et al. 

Homocysteine versus the vitamins folate, B6, 

and B12 as predictors of cognitive function and 

decline in older high-functioning adults: 

MacArthur Studies of Successful Aging. Am J 

Med 2005; 118(2):161-167. 

113. Bowirrat A, Friedland RP, Farrer L, Baldwin C, 

Korczyn A. Genetic and environmental risk 

factors for Alzheimer's disease in Israeli Arabs. J 

Mol Neurosci 2002; 19(1-2):239-245. 

114. Elias MF, Sullivan LM, D'Agostino RB et al. 

Homocysteine and cognitive performance in the 

framingham offspring study: age is important. 

Am J Epidemiol 2005; 162(7):644-653. 
148

115. Ravaglia G, Forti P, Maioli F et al. Homocysteine 

and folate as risk factors for dementia and 

Alzheimer disease. Am J Clin Nutr 2005; 

82(3):636-643. 

116. Engelborghs S, Vloeberghs E, Maertens K et al. 

Correlations between cognitive, behavioural and 

psychological findings and levels of vitamin B12 

and folate in patients with dementia. Int J Geriatr 

Psychiatry 2004; 19(4):365-370. 

117. Stuerenburg HJ, MuellerThomsen T, Methner A. 

Vitamin B 12 plasma concentrations in Alzheimer 

disease. Neuroendocrinol Lett 2004; 25(3):176-

177. 

118. Whyte EM, Mulsant BH, Butters MA et al. 

Cognitive and behavioral correlates of low vitamin 

B12 levels in elderly patients with progressive 

dementia. Am J Geriatr Psychiatry 2002; 

10(3):321-327. 

119. Andersen-Ranberg K, Vasegaard L, Jeune B. 

Dementia is not inevitable: a population-based 

study of Danish centenarians. J Gerontol B 

Psychol Sci Soc Sci 2001; 56(3):P152-159. 

120. Anello G, Gueant-Rodriguez RM, Bosco P et al. 

Homocysteine and methylenetetrahydrofolate 

reductase polymorphism in Alzheimer's disease. 

Neuroreport 2004; 15(5):859-861. 

121. Argyriadou S, Vlachonikolis I, Melisopoulou H, 

Katachanakis K, Lionis C. In what extent anemia 

coexists with cognitive impairment in elderly: a 

cross-sectional study in Greece. BMC Fam Pract 

2001; 2(1):5. 

122. Cacabelos R, Fernandez-Novoa L, Corzo L et al. 

Genomics and phenotypic profiles in dementia: 

implications for pharmacological treatment. 

Methods Find Exp Clin Pharmacol 2004; 

26(6):421-444. 

123. Clarke R, Smith AD, Jobst KA et al. Folate, 

vitamin B12, and serum total homocysteine levels 

in confirmed Alzheimer disease. Arch Neurol 

1998; 55(11):1449-1455. 

124. Gottfries J, Blennow K, Lehmann MW, Regland 

B, Gottfries CG. One-carbon metabolism and 

other biochemical correlates of cognitive 

impairment as visualized by principal component 

analysis. J Geriatr Psychiatry Neurol 2001; 

14(3):109-114. 

125. Joosten E, Lesaffre E, Riezler R et al. Is metabolic 

evidence for vitamin B-12 and folate deficiency 

more frequent in elderly patients with Alzheimer's 

disease? J Gerontol A Biol Sci Med Sci 1997; 

52(2):M76-M79. 

126. McCaddon A, Blennow K, Hudson P et al. 

Transcobalamin polymorphism and serum holotranscobalamin in relation to Alzheimer's 

disease. Dement Geriatr Cogn Disord 2004; 

71(3):215-221. 

127. Mizrahi EH, Bowirrat A, Jacobsen DW et al. 

Plasma homocysteine, vitamin B12 and folate in 

Alzheimer's patients and healthy Arabs in Israel. 

J Neurol Sci 2004; 227(1):109-113. 

128. Nilsson K, Gustafson L, Faldt R et al. 

Hyperhomocysteinaemia--a common finding in a 

psychogeriatric population. Eur J Clin Invest 

1996; 26(10):853-859. 

129. Postiglione A, Milan G, Ruocco A et al. Plasma 

folate, vitamin B(12), and total homocysteine 

and homozygosity for the C677T mutation of the 

5,10-methylene tetrahydrofolate reductase gene 

in patients with Alzheimer's dementia. A casecontrol study. Gerontology 2001; 47(6):324-329. 

130. Quadri P, Fragiacomo C, Pezzati R et al. 

Homocysteine, folate, and vitamin B-12 in mild 

cognitive impairment, Alzheimer disease, and 

vascular dementia. Am J Clin Nutr 2004; 

80(1):114-122. 

131. Ravaglia G, Forti P, Maioli F et al. 

Homocysteine and cognitive function in healthy 

elderly community dwellers in Italy. Am J Clin 

Nutr 2003; 77(3):668-673. 

132. Religa D, Styczynska M, Peplonska B et al. 

Homocysteine, apolipoproteine E and 

methylenetetrahydrofolate reductase in 

Alzheimer's disease and mild cognitive 

impairment. Dement Geriatr Cogn Disord 2003; 

16(2):64-70. 

133. Shahar A, Feiglin L, Shahar DR, Levy S, 

Seligsohn U. High prevalence and impact of 

subnormal serum vitamin B12 levels in Israeli 

elders admitted to a geriatric hospital. J Nutr 

Health Aging 2001; 5(2):124-127. 

134. Tripathi M, Sheshadri S, Padma MV et al. Serum 

cobalamin levels in dementias. Neurol India 

2001; 49(3):284-286. 

135. Regland B, Gottfries CG, Oreland L, 

Svennerholm L. Low B12 levels related to high 

activity of platelet MAO in patients with 

dementia disorders. A retrospective study. Acta 

Psychiatri Scand 1988; 78(4):451-457. 

136. Refsum H, Smith AD. Low vitamin B-12 status 

in confirmed Alzheimer's disease as revealed by 

serum holotranscobalamin. J Neurol Neurosurg 

Psychiatry 2003; 74(7):959-961. 
149

137. Nagga K, Rajani R, Mardh E et al. Cobalamin, 

folate, methylmalonic acid, homocysteine, and 

gastritis markers in dementia. Dement Geriatr 

Cogn Disord 2003; 16(4):269-275. 

138. Nilsson SE, Takkinen S, Tryding N et al. 

Association of biochemical values with morbidity 

in the elderly: a population-based Swedish study 

of persons aged 82 or more years. Scand J Clin 

Lab Invest 2003; 63(7-8):457-466. 

139. Serot JM, Christmann D, Dubost T, Bene MC, 

Faure GC. CSF-folate levels are decreased in lateonset AD patients. J Neural Transm 2001; 

108(1):93-99. 

140. Maxwell CJ, Hogan DB, Ebly EM. Serum folate 

levels and subsequent adverse cerebrovascular 

outcomes in elderly persons. Dement Geriatr Cogn 

Disord 2002; 13(4):225-234. 

141. Stewart R, Asonganyi B, Sherwood R. Plasma 

homocysteine and cognitive impairment in an 

older British African-Caribbean population. J Am 

Geriatr Soc 2002; 50(7):1227-1232. 

142. Jones S, Small BJ, Fratiglioni L, Backman L. 

Predictors of cognitive change from preclinical to 

clinical Alzheimer's disease. Brain Cogn 2002; 

49(2):210-213. 

143. Selhub J, Jacques PF, Wilson PWF, Rush D, 

Rosenberg IH. Vitamin status and intake as 

primary determinants of homocysteinemia in an 

elderly population. JAMA 1993; 270(22):2693-

2698. 

144. Selhub J, Bagley LC, Miller J, Rosenberg IH. B 

vitamins, homocysteine, and neurocognitive 

function in the elderly. Am J Clin Nutr 2000; 

71(2):614S-620S. 

145. Smith AD. Homocysteine, B vitamins, and 

cognitive deficit in the elderly. Am J Clin Nutr 

2002; 75:785-786. 

146. Garcia A, Zanibbi K. Homocysteine and cognitive 

function in elderly people. Can Med Assoc J 2004; 

171(8):897-904. 

147. Morris MS, Jacques PF, Rosenberg IH, Selhub J, 

National Health and Nutrition Examination 

Survey. Hyperhomocysteinemia associated with 

poor recall in the third National Health and 

Nutrition Examination Survey. Am J Clin Nutr 

2001; 73(5):927-933. 

148. Yukawa M, Naka H, Murata Y et al. Folic acidresponsive neurological diseases in Japan. J Nutr 

Sci Vitaminol (Tokyo) 2001; 47(3):181-187. 

149. Vermeulen EGJ, Stehouwer CDA, Valk J et al. 

Effect of homocysteine-lowering treatment with 

folic acid plus vitamin B6 on cerebrovascular 

atherosclerosis and white matter abnormalities as 

determined by MRA and MRI: a placebocontrolled, randomized trial. Eur J Clin Invest 

2004; 34(4):256-261. 

150. Marks J. The safety of the vitamins: an 

overview. Int J Vitam Nutr Res Suppl 1989; 

30:12-20. 

151. Snodgrass SR. Vitamin neurotoxicity. Mol 

Neurobiol 1992; 6(1):41-73. 

152. Wrenn KD, Murphy F, Slovis CM. A toxicity 

study of parenteral thiamine hydrochloride. Ann 

Emerg Med 1989; 18(8):167-170. 

153. Cohen M, Bendich A. Safety of pyridoxine--a 

review of human and animal studies. Toxicol 

Lett 1986; 34(2-3):129-139. 

154. Duvoisin RC, Yahr MD, Cote LD. Pyridoxine 

reversal of L-dopa effects in Parkinsonism. Trans 

Am Neurol Assoc 1969; 94:81-84. 

155. Fahn S. "On-off" phenomenon with levodopa 

therapy in Parkinsonism. Clinical and 

pharmacologic correlations and the effect of 

intramuscular pyridoxine. Neurology 1974; 

24(5):431-441. 

156. Hsu TH, Bianchine JR, Preziosi TJ, Messiha FS. 

Effect of pyridoxine on levodopa metabolism in 

normal and parkinsonian subjects. Proc Soc Exp 

Biol Med 1973; 143(2):578-581. 

157. Leon AS, Spiegel HE, Thomas G, Abrams WB. 

Pyridoxine antagonism of levodopa in 

parkinsonism. JAMA 1971; 218(13):1924-1927. 

158. Mars H. Metabolic interactions of pyridoxine, 

levodopa, and carbidopa in Parkinson's disease. 

Trans Am Neurol Assoc 1973; 98:241-245. 

159. Mars H. Levodopa, carbidopa, and pyridoxine in 

Parkinson disease. Metabolic interactions. Arch 

Neurol 1974; 30(6):444-447. 

160. Bhagavan HN, Brin M. Drug--vitamin B6 

interaction. Curr Concepts Nutr 1983; 12:1-12. 

161. Campbell NR. How safe are folic acid 

supplements? Arch Intern Med 1996; 

156(15):1638-1644. 

162. Hathcock JN. Vitamins and minerals: efficacy 

and safety. Am J Clin Nutr 1997; 66(2):427-437. 
150

163. U.S.Department of Agriculture. USDA Database 

for the Flavonoid Content of Selected Foods. 3-

25-2003. Beltsville, Maryland 20705, USDA 

Agricultural Research Service, Beltsville Human 

Nutrition Research Center, Nutrient Data 

Laboratory. 

164. Moyer RA, Hummer KE, Finn CE, Frei B, 

Wrolstad RE. Anthocyanins, phenolics, and 

antioxidant capacity in diverse small fruits: 

vaccinium, rubus, and ribes. J Agric Food Chem 

2002; 50(3):519-525. 

165. Siriwoharn T, Wrolstad RE, Finn CE, Pereira CB. 

Influence of cultivar, maturity, and sampling on 

blackberry (Rubus L. Hybrids) anthocyanins, 

polyphenolics, and antioxidant properties. J Agric 

Food Chem 2004; 52(26):8021-8030. 

166. Prior RL, Hoang H, Gu L et al. Assays for 

hydrophilic and lipophilic antioxidant capacity 

(oxygen radical absorbance capacity 

(ORAC(FL))) of plasma and other biological and 

food samples. J Agric Food Chem 2003; 

51(11):3273-3279. 

167. Halvorsen BL, Holte K, Myhrstad MC et al. A 

systematic screening of total antioxidants in 

dietary plants. J Nutr 2002; 132(3):461-471. 

168. Wu X, Beecher GR, Holden JM et al. Lipophilic 

and hydrophilic antioxidant capacities of common 

foods in the United States. J Agric Food Chem 

2004; 52(12):4026-4037. 

169. Saija A, Princi P, D'Amico N, De Pasquale R, 

Costa G. Effect of Vaccinium myrtillus 

anthocyanins on triiodothyronine transport into 

brain in the rat. Pharmacol Res 1990; 22(Suppl 

3):59-60. 

170. Shukitt-Hale B, Galle E, Methner A, Carey A, 

Bielinski D. Dietary supplementation with fruit 

polyphenolics ameliorates age-related deficits in 

behavior and neuronal markers of inflammation 

and oxidative stress. Age 2005; 27:49-57. 

171. Wang BH, Foo LY, Polya GM. Differential 

inhibition of eukaryote protein kinases by 

condensed tannins. Phytochemistry 1996; 

43(2):359-365. 

172. Andres-Lacueva C, Shukitt-Hale B, Galli RL et al. 

Anthocyanins in aged blueberry-fed rats are found 

centrally and may enhance memory. Nutr 

Neurosci 2005; 8(2):111-120. 

173. Bickford PC, Shukitt-Hale B, Joseph J. Effects of 

aging on cerebellar noradrenergic function and 

motor learning: nutritional interventions. Mech 

Ageing Dev 1999; 111(2-3):141-154. 

174. Bickford PC, Gould T, Briederick L et al. 

Antioxidant-rich diets improve cerebellar 

physiology and motor learning in aged rats. 

Brain Res 2000; 866(1-2):211-217. 

175. Casadesus G, Shukitt-Hale B, Stellwagen HM et 

al. Modulation of hippocampal plasticity and 

cognitive behavior by short-term blueberry 

supplementation in aged rats. Nutr Neurosci 

2004; 7(5-6):309-316. 

176. Goyarzu P, Malin DH, Lau FC et al. Blueberry 

supplemented diet: effects on object recognition 

memory and nuclear factor-kappa B levels in 

aged rats. Nutr Neurosci 2004; 7(2):75-83. 

177. Joseph JA, Denisova N, Fisher D et al. 

Membrane and receptor modifications of 

oxidative stress vulnerability in aging. 

Nutritional considerations. Ann N Y Acad Sci 

1998; 854:268-276. 

178. Joseph JA, Shukitt-Hale B, Denisova NA et al. 

Long-term dietary strawberry, spinach, or 

vitamin E supplementation retards the onset of 

age-related neuronal signal-transduction and 

cognitive behavioral deficits. J Neurosci 1998; 

18(19):8047-8055. 

179. Joseph JA, Shukitt-Hale B, Denisova NA et al. 

Reversals of age-related declines in neuronal 

signal transduction, cognitive, and motor 

behavioral deficits with blueberry, spinach, or 

strawberry dietary supplementation. J Neurosci 

1999; 19(18):8114-8121. 

180. Joseph JA, Denisova NA, Arendash G et al. 

Blueberry supplementation enhances signaling 

and prevents behavioral deficits in an Alzheimer 

disease model. Nutr Neurosci 2003; 6(3):153-

162. 

181. Joseph JA, Fisher DR, Carey AN. Fruit extracts 

antagonize Abeta- or DA-induced deficits in 

Ca2+ flux in M1-transfected COS-7 cells. J 

Alzheimers Dis 2004; 6(4):403-411. 

182. Martin A, Prior R, Shukitt-Hale B, Cao G, 

Joseph JA. Effect of fruits, vegetables, or 

vitamin E--rich diet on vitamins E and C 

distribution in peripheral and brain tissues: 

implications for brain function. J Gerontol A 

Biol Sci Med Sci 2000; 55(3):B144-B151. 

183. Rabin BM, Joseph JA, Shukitt-Hale B. Effects of 

age and diet on the heavy particle-induced 

disruption of operant responding produced by a 

ground-based model for exposure to cosmic rays. 

Brain Res 2005; 1036(1-2):122-129. 
151

184. Rabin BM, Carrihill-Knoll K, Carey A, ShukittHale B. Effect of diet on the disruption of operant 

responding at different ages following exposure to 

56Fe particles. Age 2005; 27:69-73. 

185. Shukitt-Hale B, Smith DE, Meydani M, Joseph 

JA. The effects of dietary antioxidants on 

psychomotor performance in aged mice. Expl 

Gerontol 1999; 34(6):797-808. 

186. Youdim KA, Shukitt-Hale B, Martin A et al. 

Short-term dietary supplementation of blueberry 

polyphenolics: Beneficial effects on aging brain 

performance and peripheral tissue function. Nutr 

Neuroscience 2000; 3:383-397. 

187. Lindner MD. Reliability, distribution, and validity 

of age-related cognitive deficits in the Morris 

water maze. Neurobiol Learn Mem 1997; 

68(3):203-220. 

188. Golbe LI, Farrell TM, Davis PH. Case-control 

study of early life dietary factors in Parkinson's 

disease. Arch Neurol 1988; 45(12):1350-1353. 

189. Canter PH, Ernst E. Anthocyanosides of 

Vaccinium myrtillus (bilberry) for night vision--a 

systematic review of placebo-controlled trials. 

Surv Ophthalmol 2004; 49(1):38-50. 

190. Morazzoni P, Bombardelli E. Vaccinium myrtillus 

L. Fitoterapia 1996; 67(1):3-29. 

191. Leventhal LJ, Boyce EG, Zurier RB. Treatment 

of rheumatoid arthritis with blackcurrant seed 

oil. Br J Rheumatol 1994; 33(9):847-852. 

192. Suvarna R, Pirmohamed M, Henderson L. 

Possible interaction between warfarin and 

cranberry juice. BMJ 2003; 327(7429):1454. 

193. Steckler T, Muir JL. Measurement of cognitive 

function: relating rodent performance with 

human minds. Brain Res Cogn Brain Res 1996; 

3(3-4):299-308. 

194. D'Mello GD, Steckler T. Animal models in 

cognitive behavioural pharmacology: an 

overview. Brain Res Cogn Brain Res 1996; 3(3-

4):345-352. 

195. Moher D, Schulz KF, Altman DG, for the 

CONSORT group. The CONSORT Statement: 

Revised Recommendations for Improving the 

Quality of Reports of Parallel-Group 

Randomized Trials. Ann Intern Med 2001; 

134(8):657-662. 

196. Altman DG, Schulz KF, Moher D et al. The 

Revised CONSORT Statement for Reporting 

Randomized Trials: Explanation and 

Elaboration. Ann Intern Med 2001; 134(8):663-

694. 

197. van der Staay FJ. Assessment of age-associated 

cognitive deficits in rats: a tricky business. 

Neurosci Biobehav Rev 2002; 26(7):753-759. 
152

Bibliography 

B Vitamins – Animal / In Vitro Studies 

Ciccia RM, Langlais PJ. An examination of the 

synergistic interaction of ethanol and thiamine 

deficiency in the development of neurological signs 

and long-term cognitive and memory impairments. 

Alcohol Clin Exp Res 2000; 24(5):622-634. 

Driskell JA, Strickland LA, Poon CH, Foshee DP. 

The vitamin B6 requirement of the male rat as 

determined by behavioral patterns, brain pyridoxal 

phosphate and nucleic acid composition and 

erythrocyte alanine aminotransferase activity. J Nutr 

1973; 103(5):670-680. 

Duan W, Ladenheim B, Cutler RG et al. Dietary 

folate deficiency and elevated homocysteine levels 

endanger dopaminergic neurons in models of 

Parkinson's disease. J Neurochem 2002; 80(1):101-

110. 

Fuso A, Seminara L, Cavallaro RA, D'Anselmi F, 

Scarpa S. S-adenosylmethionine/homocysteine cycle 

alterations modify DNA methylation status with 

consequent deregulation of PS1 and BACE and betaamyloid production. Mol Cell Neurosci 2005; 

28(1):195-204. 

Jolicoeur FB, Rondeau DB, Barbeau A, Wayner MJ. 

Comparison of neurobehavioral effects induced by 

various experimental models of ataxia in the rat. 

Neurobehav Toxicol 1979; 1(S1):175-178. 

Jolicoeur FB, Rondeau DB, Hamel E, Butterworth 

RF, Barbeau A. Measurement of ataxia and related 

neurological signs in the laboratory rat. Can J Neurol 

Sci 1979; 6(2):209-215. 

Kim JM, Lee H, Chang N. Hyperhomocysteinemia 

due to short-term folate deprivation is related to 

electron microscopic changes in the rat brain. J Nutr 

2002; 132(11):3418-3421. 

Kruman II, Kumaravel TS, Lohani A et al. Folic acid 

deficiency and homocysteine impair DNA repair in 

hippocampal neurons and sensitize them to amyloid 

toxicity in experimental models of Alzheimer's 

disease. J Neurosci 2002; 22(5):1752-1762. 

Lee H, Kim HJ, Kim JM, Chang N. Effects of dietary 

folic acid supplementation on cerebrovascular 

endothelial dysfunction in rats with induced 

hyperhomocysteinemia. Brain Res 2004; 996(2):139-

147. 

Lee H, Kim JM, Kim HJ, Lee I, Chang N. Folic acid 

supplementation can reduce the endothelial damage 

in rat brain microvasculature due to 

hyperhomocysteinemia. J Nutr 2005; 135(3):544-

548. 

Manz HJ, Robertson DM. Vascular permeability to 

horseradish peroxidase in brainstem lesions of 

thiamine-deficient rats. Am J Pathol 1972; 66(3):565-

576. 

Masuda Y, Kokubu T, Yamashita M, Ikeda H, Inoue 

S. EGG phosphatidylcholine combined with vitamin 

B12 improved memory impairment following 

lesioning of nucleus basalis in rats. Life Sci 1998; 

62(9):813-822. 

Mattson MP, Chan SL, Duan W. Modification of 

brain aging and neurodegenerative disorders by 

genes, diet, and behavior. Physiol Rev 2002; 

82(3):637-672. 

Robertson DM, Manz HJ. Effect of thiamine 

deficiency on the competence of the blood-brain 

barrier to albumin labeled with fluorescent dyes. Am 

J Pathol 1971; 63(3):393-402. 

Shea TB, Rogers E. Folate quenches oxidative 

damage in brains of apolipoprotein E-deficient mice: 

augmentation by vitamin E. Brain Res Mol Brain Res 

2002; 108(1-2):1-6. 

Shea TB, Rogers E, Ashline D et al. Vitamin E 

deficiency does not induce compensatory antioxidant 

increases in central nervous system tissue of 

apolipoprotein E-deficient mice. J Alzheimers Dis 

2003; 5(1):9-14. 

Shea TB, Rogers E, Ashline D, Ortiz D, Sheu MS. 

Apolipoprotein E deficiency promotes increased 

oxidative stress and compensatory increases in 

antioxidants in brain tissue. Free Radic Biol Med 

2002; 33(8):1115-1120. 

Terasawa M, Nakahara T, Tsukada N, Sugawara A, 

Itokawa Y. The relationship between thiamine 

deficiency and performance of a learning task in rats. 

Metabol Brain Dis 1999; 14(3):137-148. 

Tunnicliff G, Wimer RE, Roberts E. Pyridoxine 

dietary levels and open-field activity of inbred mice. 

Brain Res 1972; 42(1):234-238. 
153

Warnock LG, Burkhalter VJ. Evidence of 

malfunctioning blood-brain barrier in experimental 

thiamine deficiency in rats. J Nutr 1968; 94(2):256-

260. 

Zimitat C, Kril J, Harper CG, Nixon PF. Progression 

of neurological disease in thiamin-deficient rats is 

enhanced by ethanol. Alcohol 1990; 7(6):493-501. 

B Vitamins – Human Studies 

Abyad A. Prevalence of vitamin B12 deficiency 

among demented patients and cognitive recovery 

with cobalamin replacement. J Nutr Health Aging 

2002; 6(4):254-260. 

Aisen PS, Egelko S, Andrews H et al. A pilot study 

of vitamins to lower plasma homocysteine levels in 

Alzheimer disease. Am J Geriatr Psychiatry 2003; 

11(2):246-249. 

Andersen-Ranberg K, Vasegaard L, Jeune B. 

Dementia is not inevitable: a population-based study 

of Danish centenarians. J Gerontol B Psychol Sci Soc 

Sci 2001; 56(3):P152-159. 

Anello G, Gueant-Rodriguez RM, Bosco P et al. 

Homocysteine and methylenetetrahydrofolate 

reductase polymorphism in Alzheimer's disease. 

Neuroreport 2004; 15(5):859-861. 

Argyriadou S, Vlachonikolis I, Melisopoulou H, 

Katachanakis K, Lionis C. In what extent anemia 

coexists with cognitive impairment in elderly: a 

cross-sectional study in Greece. BMC Fam Pract 

2001; 2(1):5. 

Assantachai P, Yamwong P, Chongsuphaijaisiddhi T. 

Relationships of vitamin B1, B12, folate and the 

cognitive ability of the Thai rural elderly. J Med 

Assoc Thai 1997; 80(11):700-705. 

Blass JP, Gleason P, Brush D, DiPonte P, Thaler H. 

Thiamine and Alzheimer's disease. A pilot study. 

Arch Neurol 1988; 45(8):833-835. 

Bowirrat A, Friedland RP, Farrer L, Baldwin C, 

Korczyn A. Genetic and environmental risk factors 

for Alzheimer's disease in Israeli Arabs. J Mol 

Neurosci 2002; 19(1-2):239-245. 

Bryan J, Calvaresi E, Hughes D. Short-term folate, 

vitamin B-12 or vitamin B-6 supplementation slightly 

affects memory performance but not mood in women 

of various ages. J Nutr 2002; 132(6):1345-1356. 

Cacabelos R, Fernandez-Novoa L, Corzo L et al. 

Genomics and phenotypic profiles in dementia: 

implications for pharmacological treatment. Methods 

Find Exp Clin Pharmacol 2004; 26(6):421-444. 

Carmel R, Gott PS, Waters CH et al. The frequently 

low cobalamin levels in dementia usually signify 

treatable metabolic, neurologic and 

electrophysiologic abnormalities. Eur J Haematology 

1995; 54(4):245-253. 

Chen H, Zhang SM, Schwarzschild MA et al. Folate 

intake and risk of Parkinson's disease. Am J 

Epidemiol 2004; 160(4):368-375. 

Clarke R, Harrison G, Richards S, Vital Trial 

Collaborative Group. Effect of vitamins and aspirin 

on markers of platelet activation, oxidative stress and 

homocysteine in people at high risk of dementia. J 

Intern Med 2003; 254(1):67-75. 

Clarke R, Smith AD, Jobst KA et al. Folate, vitamin 

B12, and serum total homocysteine levels in 

confirmed Alzheimer disease. Arch Neurol 1998; 

55(11):1449-1455. 

Coimbra CG, Junqueira VB. High doses of riboflavin 

and the elimination of dietary red meat promote the 

recovery of some motor functions in Parkinson's 

disease patients. Braz J Med Biol Res 2003; 

36(10):1409-1417. 

Deijen JB, Slump E, Wouters-Wesseling W et al. 

Nutritional intake and daily functioning of 

psychogeriatric nursing home residents. J Nutr Health 

Aging 2003; 7(4):242-246. 

Deijen JB, van der Beek EJ, Orlebeke JF, van den 

BH. Vitamin B-6 supplementation in elderly men: 

effects on mood, memory, performance and mental 

effort. Psychopharmacology 1992; 109(4):489-496. 

Elias MF, Sullivan LM, D'Agostino RB et al. 

Homocysteine and cognitive performance in the 

framingham offspring study: age is important. Am J 

Epidemiol 2005; 162(7):644-653. 

Engelborghs S, Vloeberghs E, Maertens K et al. 

Correlations between cognitive, behavioural and 

psychological findings and levels of vitamin B12 and 

folate in patients with dementia. Int J Geriatr 

Psychiatry 2004; 19(4):365-370. 
154

Fioravanti M, Ferrario E, Massaia M et al. Low folate 

levels in the cognitive decline of elderly patients and 

the efficacy of folate as a treatment for improving 

memory deficits. Arch Gerontol and Geriatrics 1997; 

26(1):1-13. 

Gold M, Chen MF, Johnson K. Plasma and red blood 

cell thiamine deficiency in patients with dementia of 

the Alzheimer's type. Arch Neurol 1995; 

52(11):1081-1086. 

Gold M, Hauser RA, Chen MF. Plasma thiamine 

deficiency associated with Alzheimer's disease but 

not Parkinson's disease. Metab Brain Dis 1998; 

13(1):43-53. 

Goodwin JS, Goodwin JM, Garry PJ. Association 

between nutritional status and cognitive functioning 

in a healthy elderly population. JAMA 1983; 

249(21):2917-2921. 

Gottfries J, Blennow K, Lehmann MW, Regland B, 

Gottfries CG. One-carbon metabolism and other 

biochemical correlates of cognitive impairment as 

visualized by principal component analysis. J Geriatr 

Psychiatry Neurol 2001; 14(3):109-114. 

Hvas AM, Juul S, Lauritzen L, Nexo E, Ellegaard J. 

No effect of vitamin B-12 treatment on cognitive 

function and depression: a randomized placebo 

controlled study. J Affect Disord 2004; 81(3):269-

273. 

Ikeda T, Yamamoto K, Takahashi K et al. Treatment 

of Alzheimer-type dementia with intravenous 

mecobalamin. Clin Ther 1992; 14(3):426-437. 

Ito T, Yamadera H, Ito R et al. Effects of vitamin 

B12 on bright light on cognitive and sleep-wake 

rhythm in Alzheimer-type dementia. Psychiatry Clin 

Neurosci 2001; 55(3):281-282. 

Jimenez-Jimenez FJ, Molina JA, Hernanz A et al. 

Cerebrospinal fluid levels of thiamine in patients with 

Parkinson's disease. Neurosci Lett 1999; 271(1):33-

36. 

Jones S, Small BJ, Fratiglioni L, Backman L. 

Predictors of cognitive change from preclinical to 

clinical Alzheimer's disease. Brain Cogn 2002; 

49(2):210-213. 

Joosten E, Lesaffre E, Riezler R et al. Is metabolic 

evidence for vitamin B-12 and folate deficiency more 

frequent in elderly patients with Alzheimer's disease? 

J Gerontol A Biol Sci Med Sci 1997; 52(2):M76-

M79. 

Kado DM, Karlamangla AS, Huang MH et al. 

Homocysteine versus the vitamins folate, B6, and 

B12 as predictors of cognitive function and decline in 

older high-functioning adults: MacArthur Studies of 

Successful Aging. Am J Med 2005; 118(2):161-167. 

Kral VA, Solyom L, Enesco H, Ledwidge B. 

Relationship of vitamin B12 and folic acid to 

memory function. Biol Psychiatry 1970; 2(1):19-26. 

Kwok T, Tang C, Woo J et al. Randomized trial of 

the effect of supplementation on the cognitive 

function of older people with subnormal cobalamin 

levels. Int J Geriatr Psychiatry 1998; 13(9):611-616. 

Lee L, Kang SA, Lee HO et al. Relationships 

between dietary intake and cognitive function level in 

Korean elderly people. Public Health 2001; 

115(2):133-138. 

Lehmann M, Regland B, Blennow K, Gottfries CG. 

Vitamin B12-B6-folate treatment improves bloodbrain barrier function in patients with 

hyperhomocysteinaemia and mild cognitive 

impairment. Dement Geriatr Cogn Disord 2003; 

16(3):145-150. 

Lewerin C, Matousek M, Steen G et al. Significant 

correlations of plasma homocysteine and serum 

methylmalonic acid with movement and cognitive 

performance in elderly subjects but no improvement 

from short-term vitamin therapy: a placebocontrolled randomized study. Am J Clin Nutr 2005; 

81(5):1155-1162. 

Malaguarnera M, Ferri R, Bella R et al. 

Homocysteine, vitamin B12 and folate in vascular 

dementia and in Alzheimer disease. Clin Chem Lab 

Med 2004; 42(9):1032-1035. 

Martin DC, Francis J, Protetch J, Huff FJ. Time 

dependency of cognitive recovery with cobalamin 

replacement: report of a pilot study. J Am Geriatr 

Society 1992; 40(2):168-172. 

Mastrogiacoma F, Bettendorff L, Grisar T, Kish SJ. 

Brain thiamine, its phosphate esters, and its 

metabolizing enzymes in Alzheimer's disease. Ann 

Neurol 1996; 39(5):585-591. 

Maxwell CJ, Hogan DB, Ebly EM. Serum folate 

levels and subsequent adverse cerebrovascular 

outcomes in elderly persons. Dement Geriatr Cogn 

Disord 2002; 13(4):225-234. 

McCaddon A, Blennow K, Hudson P et al. 

Transcobalamin polymorphism and serum holotranscobalamin in relation to Alzheimer's disease. 

Dement Geriatr Cogn Disord 2004; 71(3):215-221. 
155

McGeer PL, Zeldowicz L, McGeer EG. A clinical 

trial of folic acid in Parkinson's disease. Can Med 

Assoc J 1972; 106(2):145-146. 

Meador K, Loring D, Nichols M et al. Preliminary 

findings of high-dose thiamine in dementia of 

Alzheimer's type. J Geriatr Psychiatry Neurol 1993; 

6(4):222-229. 

Miller JW, Green R, Mungas DM, Reed BR, Jagust 

WJ. Homocysteine, vitamin B6, and vascular disease 

in AD patients. Neurology 2002; 58(10):1471-1475. 

Mimori Y, Katsuoka H, Nakamura S. Thiamine 

therapy in Alzheimer's disease. Metab Brain Dis 

1996; 11(1):89-94. 

Mitsuyama Y, Kogoh H. Serum and cerebrospinal 

fluid vitamin B12 levels in demented patients with 

CH3-B12 treatment--preliminary study. Jpn J 

Psychiatry Neurol 1988; 42(1):65-71. 

Mizrahi EH, Bowirrat A, Jacobsen DW et al. Plasma 

homocysteine, vitamin B12 and folate in Alzheimer's 

patients and healthy Arabs in Israel. J Neurol Sci 

2004; 227(1):109-113. 

Mizrahi EH, Jacobsen DW, Debanne SM et al. 

Plasma total homocysteine levels, dietary vitamin B6 

and folate intake in AD and healthy aging. J Nutr 

Health Aging 2003; 7(3):160-165. 

Molina JA, Jimenez-Jimenez FJ, Hernanz A et al. 

Cerebrospinal fluid levels of thiamine in patients with 

Alzheimer's disease. J Neural Transm 2002; 109(7-

8):1035-1044. 

Morris MC, Evans DA, Bienias JL et al. Dietary 

folate and vitamin B12 intake and cognitive decline 

among community-dwelling older persons. Arch 

Neurol 2005; 62(4):641-645. 

Nagga K, Rajani R, Mardh E et al. Cobalamin, folate, 

methylmalonic acid, homocysteine, and gastritis 

markers in dementia. Dement Geriatr Cogn Disord 

2003; 16(4):269-275. 

Nilsson K, Gustafson L, Faldt R et al. 

Hyperhomocysteinaemia--a common finding in a 

psychogeriatric population. Eur J Clin Invest 1996; 

26(10):853-859. 

Nilsson K, Gustafson L, Hultberg B. Improvement of 

cognitive functions after cobalamin/folate 

supplementation in elderly patients with dementia 

and elevated plasma homocysteine. Int J Geriatr 

Psychiatry 2001; 16(6):609-614. 

Nilsson SE, Takkinen S, Tryding N et al. Association 

of biochemical values with morbidity in the elderly: a 

population-based Swedish study of persons aged 82 

or more years. Scand J Clin Lab Invest 2003; 63(7-

8):457-466. 

Nolan KA, Black RS, Sheu KF, Langberg J, Blass JP. 

A trial of thiamine in Alzheimer's disease. Arch 

Neurol 1991; 48(1):81-83. 

Postiglione A, Milan G, Ruocco A et al. Plasma 

folate, vitamin B(12), and total homocysteine and 

homozygosity for the C677T mutation of the 5,10-

methylene tetrahydrofolate reductase gene in patients 

with Alzheimer's dementia. A case-control study. 

Gerontology 2001; 47(6):324-329. 

Quadri P, Fragiacomo C, Pezzati R et al. 

Homocysteine, folate, and vitamin B-12 in mild 

cognitive impairment, Alzheimer disease, and 

vascular dementia. Am J Clin Nutr 2004; 80(1):114-

122. 

Rapin JR, LePoncin M, Grebyl J. Blood folates 

deficiencies and cognitive functions in aging. Trends 

Biomed Gerontol 1988; 1:315-323. 

Ravaglia G, Forti P, Maioli F et al. Homocysteine 

and folate as risk factors for dementia and Alzheimer 

disease. Am J Clin Nutr 2005; 82(3):636-643. 

Ravaglia G, Forti P, Maioli F et al. Homocysteine 

and cognitive function in healthy elderly community 

dwellers in Italy. Am J Clin Nutr 2003; 77(3):668-

673. 

Ravaglia G, Forti P, Maioli F et al. Elevated plasma 

homocysteine levels in centenarians are not 

associated with cognitive impairment. Mech Ageing 

Dev 2000; 121(1-3):251-261. 

Refsum H, Smith AD. Low vitamin B-12 status in 

confirmed Alzheimer's disease as revealed by serum 

holotranscobalamin. J Neurol Neurosurg Psychiatry 

2003; 74(7):959-961. 

Regland B, Gottfries CG, Oreland L, Svennerholm L. 

Low B12 levels related to high activity of platelet 

MAO in patients with dementia disorders. A 

retrospective study. Acta Psychiatri Scand 1988; 

78(4):451-457. 

Religa D, Styczynska M, Peplonska B et al. 

Homocysteine, apolipoproteine E and 

methylenetetrahydrofolate reductase in Alzheimer's 

disease and mild cognitive impairment. Dement 

Geriatr Cogn Disord 2003; 16(2):64-70. 

Renvall MJ, Spindler AA, Ramsdell JW, Paskvan M. 

Nutritional status of free-living Alzheimer's patients. 

Am J Med Sci 1989; 298(1):20-27. 
156

Requejo AM, Ortega RM, Robles F et al. Influence 

of nutrition on cognitive function in a group of 

elderly, independently living people. Eur J Clin Nutr 

2003; 57(Suppl 1):S54-S57. 

Scileppi KP, Blass JP, Baker HG. Circulating 

vitamins in Alzheimer's dementia as compared with 

other dementias. J Am Geriatr Soc 1984; 32(10):709-

711. 

Seal EC, Metz J, Flicker L, Melny J. A randomized, 

double-blind, placebo-controlled study of oral 

vitamin B12 supplementation in older patients with 

subnormal or borderline serum vitamin B12 

concentrations. J Am Geriatr Soc 2002; 50(1):146-

151. 

Serot JM, Christmann D, Dubost T, Bene MC, Faure 

GC. CSF-folate levels are decreased in late-onset AD 

patients. J Neural Transm 2001; 108(1):93-99. 

Seshadri S, Beiser A, Selhub J et al. Plasma 

homocysteine as a risk factor for dementia and 

Alzheimer's disease. N Engl J Med 2002; 346(7):476-

483. 

Shahar A, Feiglin L, Shahar DR, Levy S, Seligsohn 

U. High prevalence and impact of subnormal serum 

vitamin B12 levels in Israeli elders admitted to a 

geriatric hospital. J Nutr Health Aging 2001; 

5(2):124-127. 

Shaw DM, Macsweeney DA, Johnson AL et al. 

Folate and amine metabolites in senile dementia: a 

combined trial and biochemical study. Psychol Med 

1971; 1(2):166-171. 

Snowdon DA, Tully CL, Smith CD, Riley KP, 

Markesbery WR. Serum folate and the severity of 

atrophy of the neocortex in Alzheimer disease: 

findings from the Nun study. Am J Clin Nutr 2000; 

71(4):993-998. 

Sommer BR, Hoff AL, Costa M. Folic acid 

supplementation in dementia: a preliminary report. J 

Geriatr Psychiatry Neurol 2003; 16(3):156-159. 

Stewart R, Asonganyi B, Sherwood R. Plasma 

homocysteine and cognitive impairment in an older 

British African-Caribbean population. J Am Geriatr 

Soc 2002; 50(7):1227-1232. 

Stuerenburg HJ, MuellerThomsen T, Methner A. 

Vitamin B 12 plasma concentrations in Alzheimer 

disease. Neuroendocrinol Lett 2004; 25(3):176-177. 

Teunisse S, Bollen AE, van Gool WA, Walstra GJ. 

Dementia and subnormal levels of vitamin B12: 

effects of replacement therapy on dementia. J Neurol 

1996; 243(7):522-529. 

Tripathi M, Sheshadri S, Padma MV et al. Serum 

cobalamin levels in dementias. Neurol India 2001; 

49(3):284-286. 

Tucker KL, Qiao N, Scott T, Rosenberg I, Spiro A, 

III. High homocysteine and low B vitamins predict 

cognitive decline in aging men: the Veterans Affairs 

Normative Aging Study. Am J Clin Nutr 2005; 

82(3):627-635. 

van Asselt DZ, Pasman JW, van Lier HJ et al. 

Cobalamin supplementation improves cognitive and 

cerebral function in older, cobalamin-deficient 

persons. J Gerontol A Biol Sci Med Sci 2001; 

56(12):M775-M779. 

Wang HX, Wahlin A, Basun H et al. Vitamin B(12) 

and folate in relation to the development of 

Alzheimer's disease. Neurology 2001; 56(9):1188-

1194. 

Whyte EM, Mulsant BH, Butters MA et al. Cognitive 

and behavioral correlates of low vitamin B12 levels 

in elderly patients with progressive dementia. Am J 

Geriatr Psychiatry 2002; 10(3):321-327. 

Woitalla D, Kuhn W, Muller T. MTHFR C677T 

polymorphism, folic acid and hyperhomocysteinemia 

in levodopa treated patients with Parkinson's disease. 

J Neural Transm Suppl 2004;(68):15-20.

Berries 

Andres-Lacueva C, Shukitt-Hale B, Galli RL et al. 

Anthocyanins in aged blueberry-fed rats are found 

centrally and may enhance memory. Nutr Neurosci 

2005; 8(2):111-120. 

Bickford PC, Gould T, Briederick L et al. 

Antioxidant-rich diets improve cerebellar physiology 

and motor learning in aged rats. Brain Res 2000; 

7866(1-2):211-217. 
157

Bickford PC, Shukitt-Hale B, Joseph J. Effects of 

aging on cerebellar noradrenergic function and motor 

learning: nutritional interventions. Mech Ageing Dev 

1999; 111(2-3):141-154. 

Casadesus G, Shukitt-Hale B, Stellwagen HM et al. 

Modulation of hippocampal plasticity and cognitive 

behavior by short-term blueberry supplementation in 

aged rats. Nutr Neurosci 2004; 7(5-6):309-316. 

Golbe LI, Farrell TM, Davis PH. Case-control study 

of early life dietary factors in Parkinson's disease. 

Arch Neurol 1988; 45(12):1350-1353. 

Goyarzu P, Malin DH, Lau FC et al. Blueberry 

supplemented diet: effects on object recognition 

memory and nuclear factor-kappa B levels in aged 

rats. Nutr Neurosci 2004; 7(2):75-83. 

Joseph JA, Denisova N, Fisher D et al. Membrane 

and receptor modifications of oxidative stress 

vulnerability in aging. Nutritional considerations. 

Ann N Y Acad Sci 1998; 854:268-276. 

Joseph JA, Denisova NA, Arendash G et al. 

Blueberry supplementation enhances signaling and 

prevents behavioral deficits in an Alzheimer disease 

model. Nutr Neurosci 2003; 6(3):153-162. 

Joseph JA, Fisher DR, Carey AN. Fruit extracts 

antagonize Abeta- or DA-induced deficits in Ca2+ 

flux in M1-transfected COS-7 cells. J Alzheimers Dis 

2004; 6(4):403-411. 

Joseph JA, Shukitt-Hale B, Denisova NA et al. 

Reversals of age-related declines in neuronal signal 

transduction, cognitive, and motor behavioral deficits 

with blueberry, spinach, or strawberry dietary 

supplementation. J Neurosci 1999; 19(18):8114-

8121. 

Joseph JA, Shukitt-Hale B, Denisova NA et al. Longterm dietary strawberry, spinach, or vitamin E 

supplementation retards the onset of age-related 

neuronal signal-transduction and cognitive behavioral 

deficits. J Neurosci 1998; 18(19):8047-8055. 

Martin A, Prior R, Shukitt-Hale B, Cao G, Joseph JA. 

Effect of fruits, vegetables, or vitamin E--rich diet on 

vitamins E and C distribution in peripheral and brain 

tissues: implications for brain function. J Gerontol A 

Biol Sci Med Sci 2000; 55(3):B144-B151. 

Rabin BM, Carrihill-Knoll K, Carey A, Shukitt-Hale 

B. Effect of diet on the disruption of operant 

responding at different ages following exposure to 

56Fe particles. Age 2005; 27:69-73. 

Rabin BM, Joseph JA, Shukitt-Hale B. Effects of age 

and diet on the heavy particle-induced disruption of 

operant responding produced by a ground-based 

model for exposure to cosmic rays. Brain Res 2005; 

1036(1-2):122-129. 

Saija A, Princi P, D'Amico N, De Pasquale R, Costa 

G. Effect of Vaccinium myrtillus anthocyanins on 

triiodothyronine transport into brain in the rat. 

Pharmacol Res 1990; 22(Suppl 3):59-60. 

Shukitt-Hale B, Galle E, Methner A, Carey A, 

Bielinski D. Dietary supplementation with fruit 

polyphenolics ameliorates age-related deficits in 

behavior and neuronal markers of inflammation and 

oxidative stress. Age 2005; 27:49-57. 

Shukitt-Hale B, Smith DE, Meydani M, Joseph JA. 

The effects of dietary antioxidants on psychomotor 

performance in aged mice. Expl Gerontol 1999; 

34(6):797-808. 

Wang BH, Foo LY, Polya GM. Differential 

inhibition of eukaryote protein kinases by condensed 

tannins. Phytochemistry 1996; 43(2):359-365. 

Youdim KA, Shukitt-Hale B, Martin A et al. Shortterm dietary supplementation of blueberry 

polyphenolics: Beneficial effects on aging brain 

performance and peripheral tissue function. Nutr 

Neuroscience 2000; 3:383-397 

159

List of Acronyms and Abbreviations 

Abbreviation Description

d Narrowly applicable study (referable to population category) 

dd Moderately applicable study (referable to population category) 

ddd Broadly applicable study (referable to population category) 

+ Normal animals performed better than B vitamin-deficient animals 

0 No difference between groups 

– Normal animals performed worse than B vitamin-deficient animals 

 Higher score indicates better cognitive function 

 Lower score indicates better cognitive function 

Quality Score: A Good quality study, least susceptible to bias See Chapter 2, Methods 

Quality Score: B Fair quality study, more susceptible to bias See Chapter 2, Methods 

Quality Score: C Poor quality study, most susceptible to bias See Chapter 2, Methods 

 

%tile Percentile 

? Unclear reporting 

Aβ Amyloid β-peptide 

AD Alzheimer’s Disease 

ADAS Alzheimer disease assessment scale 

adj Adjusted 

Aged Ctrl When compared to the aged controls 

AHRQ Agency for Healthcare Research and Quality 

An Anthocyanin 

APP Amyloid precursor protein 

ApoE Apolipoprotein E 

β Slope for the multivariate linear regression model 

B Blueberry extracts 

BB Blueberry extracts 

BBB Blood brain barrier 

BC Black currant extracts 

Blessed Behavioral rating according to Blessed et al 

BS Boysenberry extracts 

Bt Blueberry extracts, tif-blue 

btw Between 

BW Body weight 

Bw Blueberry extracts, wild 

By Boysenberry extracts 

C Cranberry extracts 

CAB Commonwealth Agricultural Bureau (Abstracts) 

CAMCOG Cambridge Subscale of CAMDEX, assesses orientation, language, 

memory, praxis, attention, abstract thinking, perception and calculation 

(includes MMSE) 

CAMDEX Cambridge Examination for Mental Disorders of the Elderly 

CB Cranberry extracts 

CERAD Consortium to Establish a Registry for Alzheimer’s Disease 

CGIC Clinical Global Impression of Change 

CI Confidence interval 

CNS Central nervous system 

CSF Cerebrospinal fluid 

CTA Conditioned taste avoidance 

Cx Control 

DRS Dementia Rating Scale 

DSM Diagnostic and Statistical Manual of Mental Disorders 
160

Abbreviation Description

EEG Electroencephalography 

eNOS Endothelial nitric oxide synthase 

EPC Evidence-based practice center 

ERK Extracellular-signal-regulated-kinase 

F344 Fischer 344 mouse strain 

FFQ Food frequency questionnaire 

FRAP Ferric-reducing ability of plasma 

FTD Fronto Temporal Dementia 

GBS Gottfries-Brane-Steen scale 

GLUT-1 Glucose transporter protein 

GTPase Guanosine triphosphase 

Haycox Behavioral scale of Haycox 

HCl Hydrochloride 

Hcy Homocysteine 

HDS Hasegawa’s Dementia Rating Scale 

HSP70 Heat shock protein 70 

IC50 Concentrations of compound required for 50 percent inhibition of 

enzyme 

IDDD Interview for Deterioration in Daily living activities in Dementia, caregiver 

assessment of functioning in the past week, subscales for initiative and 

performance; 

IGF Insulin growth factor 

IM Intramuscular 

INR International normalized ratio 

IOM Institute of Medicine 

i.p. Intraperitoneal 

IQ Intelligence quotient 

IV Intravenous 

M1AchR Muscarinic receptor subtype 1 

MMSE (-K) Mini-mental status examination (for Koreans) 

mo Month(s) 

MPTP 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine 

MTHFR Methylene tetrahydrofolate reductase 

MTP Matching-to-position 

MWM Morris water maze 

N Number of subjects 

N/A Not applicable 

NBM Nucleus basalis magnocellularis 

NCCAM National Center for Complementary and Alternative Medicine 

nd Not documented / no data 

NF-κB Nuclear factor-kappa B 

NIH National Institutes of Health 

NINCDS-ADRDA National Institute of Neurological and Communicative Disorders and 

Stroke and the Alzheimer’s Disease and Related Disorders Association 

NMTP Nonmatching-to-position 

N-RCT Non-randomized comparative trial 

NS Non-significant 

N-Sase Neutral sphingomyelin-specific phospholipase 

ODS Office of Dietary Supplements 

OR Odds ratio 

ORAC Oxygen radical absorbance capacity 

PD Parkinson’s disease 

pFe After irradiation with 56Fe 

Ph Total phenolics 

PKC Protein kinase C 
161

Abbreviation Description

PLP Pyridoxal-5’-phosphate 

po Orally 

PS Presenilin 

RAVLT Rey Auditory-Verbal Learning Test 

RAWM Radial Arm Water Maze 

RBC Red blood cell 

RCT Randomized controlled trial 

RDA Recommended Daily Allowance 

Ref Reference group for comparisons 

RMBPC Revised Memory and Behavioral Problems; 3 subscales for memory, 

depression, and disruptive behavior 

RMT Randt Memory Test 

RR Relative risk (risk ratio) 

Rx Treatment 

S Strawberry extracts 

SD Standard deviation 

S-D Sprague-Dawley 

SDAT Senile dementia of the Alzheimer’s type 

SE Standard error 

SKT Syndrom Kurztest, a short cognitive test for assessing memory and 

attention 

SNCA Alpha-synuclein gene 

Stroop Stroop Color-word Test 

T3 Triiodothyronine. 

TBARS Thiobarbituric acid-reactive substances 

TD Thiamine deficient/deficiency 

TDP Thiamine diphosphate 

TEP Technical expert panel 

TMP Thiamine monophosphate 

TPP Thiamine pyrophosphate 

Tx Treatment 

Tufts-NEMC Tufts-New England Medical Center 

UL Upper Limit 

unadj Unadjusted 

USDA US Department of Agriculture 

VCAM-1 Vascular cell adhesion molecule 

WAIS (-R) Wechsler Adult Intelligence Scale (- Revised) 

WHO World Health Organization 

WMT Wechsler verbal memory test 

wk Week(s) 

Young Ctr Compared to the young controls 

yr Year(s) 

APPENDIXES 

to 

“B Vitamins and Berries and Age-Related 

Neurodegenerative Disorders” 

Prepared by the Tufts-New England Medical Center 

Evidence-based Practice Center 

(Contract #290-02-0022)
A-1

Appendix A. Literature Search Strings 

B Vitamins (Feb 2, 2005) 

Ovid MEDLINE® <1966 to Jan Week 3 2005> 

Ovid MEDLINE® Daily Update <Jan 31, 2005> 

Ovid MEDLINE® In-Process & Other Non-Indexed Citations <Jan 31, 2005> 

CAB Abstracts <1973 to Dec 2004>

# Search History Results 

1 exp nervous system diseases/ 1259232 

2 exp Delirium, Dementia, Amnestic, Cognitive Disorders/ 93503 

3 neuron$.mp. 329067 

4 nerve cell$.mp. 7813 

5 alzheimer$.mp. 46029 

6 lewy bod$.mp. 2629 

7 brain.mp. 639058 

8 dementia.mp. 48550 

9 neurodegen$.mp. 17734 

10 or/1-9 1822067 

 

11 exp folic acid/ 21806 

12 (folate or folic acid or pteroylglutamic or folacin).mp. 28501 

13 exp Riboflavin/ 9878 

14 (Riboflavin or lactoflavin).mp. 11051 

15 exp Thiamine/ 9522 

16 Thiamine.mp. 11080 

17 exp Vitamin B 12/ 11454 

18 cobalamin$.mp. 2944 

19 cyanocobalamin$.mp. 1297 

20 exp Vitamin B 6/ 10645 

21 exp PYRIDOXINE/ 8461 

22 (pyridoxal or pyridoxamine or pyridoxine).mp. 17309 

23 (vitamin adj1 ("B1" or "B 1" or "B2" or "B 2" or "B6" or "B 6" or "B12" or 

"B 12")).mp. 

26741 

24 or/11-23 84479 

 

25 10 and 24 11080 

26 limit 25 to English language 8984 

27 limit 26 to (addresses or bibliography or biography or case reports or clinical conference or 

congresses or consensus development conference or consensus development conference, nih or 

dictionary or directory or editorial or festschrift or government publications or interview or 

lectures or legal cases or legislation or letter or news or newspaper article or patient education 

handout or periodical index or "review of reported cases") 

[Limit not valid in: CAB Abs; records were retained] 

1762 

28 26 not 27 7222 

29 remove duplicates from 28 6640 
A-2

Berries (Mar 3, 2005) 

Ovid MEDLINE® <1966 to Feb Week 4 2005> 

Ovid MEDLINE® Daily Update <Mar 02, 2005> 

Ovid MEDLINE® In-Process & Other Non-Indexed Citations <Mar 02, 2005> 

CAB Abstracts <1973 to Jan 2005> 

# Search History Results 

1 exp nervous system diseases/ 1265160

2 exp Delirium, Dementia, Amnestic, Cognitive Disorders/ 94198

3 neuron$.mp. 331088

4 nerve cell$.mp. 7842

5 alzheimer$.mp. 46489

6 parkinson$.mp. 42926

7 lewy bod$.mp. 2651

8 brain.mp. 642015

9 dementia.mp. 48839

10 neurodegen$.mp. 18012

11 or/1-10 1837302

12 limit 11 to English language 1483695

 

13 exp blueberry plant/ 33

14 blueberr$.mp. 3182

15 cranberr$.mp. 1275

16 lingonberr$.mp. 176

17 bilberr$.mp. 554

18 marionberr$.mp. 11

19 exp vaccinium/ 5126

20 vaccinium.mp. 5781

21 strawberr$.mp. 15298

22 exp fragaria/ 12515

23 fragaria.mp. 12692

24 raspberr$.mp. 5253

25 blackberry.mp. 1209

26 ribes.mp. 4419

27 currant$.mp. 3972

28 boysenberr$.mp. 116

29 or/13-28 30056

 

30 exp Flavonols/ 6888

31 flavonol$.mp. 3880

32 exp flavonoids/ 48492

33 flavonoid$.mp. 27766

34 proanthocyan$.mp. 1545

35 anthocyan$.mp. 8069

36 leucoanthocyan$.mp. 294

37 catechin$.mp. 5272

38 epicatechin$.mp. 1849

39 quercetin$.mp. 7303

40 myricetin$.mp. 765

41 procyan$.mp. 1024

42 flavonol$.mp. 3880

43 biflavonoid$.mp. 635

44 flavanone$.mp. 2305

45 flavonolignan$.mp. 101
A-3

# Search History Results 

46 flavan-3-ol$.mp. 406

47 phytochemical$.mp. 5036

48 exp cinnamates/ 10537

49 cinnamate$.mp. 2988

50 hydroxycinnamate$.mp. 507

51 chlorogenic$.mp. 2546

52 Kaempferol$.mp. 2550

53 Rutin$.mp. 3963

54 Hydroxyethylrutoside$.mp. 329

55 cyanidin$.mp. 1253

56 malvidin$.mp. 419

57 petunidin$.mp. 221

58 phloridzin$.mp. 611

59 delphinidin$.mp. 588

60 ferulic$.mp. 3010

61 peonidin$.mp. 342

62 resveratro$.mp. 1819

63 Pulchellidin$.mp. 3

64 or/30-63 76600

 

65 12 and (29 or 64) 2627

 

66 exp nervous system/ 1082233

67 limit 66 to English language 928559

68 (12 or 67) and (29 or 64) 3496

69 70 not 66 875

 

70 pterostilbene$.mp. 44

71 (flavan$ or tannin$ or phytonutri$).mp. 17564

72 (70 or 71) and (12 or 67) 361

73 76 not (66 or 69) 221

 

74 exp gooseberry/ 24

75 gooseberr$.mp. 1431

76 (74 or 75) and (12 or 67) 19

77 81 not (66 or 69 or 73) 18

 

78 exp fruit/ 44312

79 fruit$1.mp. 290648

80 "fruit fly".mp. 4006

81 (78 or 79) not 80 299608

82 87 and 12 1016

83 89 not (65 or 68 or 72 or 76) 922

 

84 or/65,69,73,77, 83 4633
B-1

Appendix B. Sample Data Extraction Forms 
B-2

Appendix B. Sample Data Extraction Forms

Human Intervention Studies

Author, Year: Ref ID: Vitamins: Objective: Study characteristics Population Controls Inclusion criteria Exclusion criteria Study design Age: Country: %Male: Setting: Race: Funding: Other: Comments: Intervention(s): Control: Total Intervention 1 Intervent

N enrolled: N analyzed: Drop-outs (%): 

Follow-up duration: Reasons for drop out: Comments: Primary outcome(s): Secondary outcome(s): Adverse events: Limitations: Quality (A/B/C): Applicability (1/2/3): Outcome(s): Results (Text) (or Definition) 
B-3

(Separate table for each outcome) Outcome (units) 

 N (Intervention) (Dose) N (Intervention) (Dose) N (Intervention) 

Baseline value (SE/SD) Final value (SE/SD) Difference (SE/SD/95% CI) P Difference Net Difference (SE/SD/95% CI) P Net difference (RR/OR/HR) 95% CI P (RR/OR/HR) IN THIS TABLE, REPLACE ITEMS IN PARENTHESES WITH ACTUAL ITEMS (EG, Vitamin B6, SE, RR) REMOVE PARENTHESES!! DOSE GOES IN TOP LINE. 2nd CELL IS FOR SE or SD
Appendix B. Sample data extraction forms 

Human correlation studies 

B-4

Human – Correlation Studies

Author, Year: Ref ID: Vitamins: Objective: Study characteristics Population Controls Inclusion criteria Exclusion criteria 

XS/Longitudinal Age: Cases: Cases: Non-c/Comparative %Male: 

Study design 

Pro/Retrospective Race: 

Country: Other: Controls: Controls: Setting: Funding: Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population of 

N enrolled: N analyzed: Drop-outs (%): 

Comments: Other predictors/outcomes reported: Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Quality (A/B/C): Applicability (1/2/3): Outcome(s): Results (Text) 
Appendix B. Sample data extraction forms 

Human correlation studies 

B-5

Correlation of Predictors with Outcomes (cross-sectional studies) 

Description of (Sr/CSF) (B vit) (unit) p (Sr/CSF) (B vit) (unit) p (Sr/CSF) (B vit) (unit) (Sr/C(Sub-) Groups N Mean SE/SD r= Mean SE/SD r= Mean SE/SD r= Mea

IN THIS TABLE, REPLACE ITEMS IN PARENTHESES WITH ACTUAL ITEMS (EG, Vitamin B6, SE, RR) REMOVE PARENTHESES!! 

Description of (Outcome) N ((Sub-) Groups N OR (Adj 1*) OR (Adj 2*) OR (Adj 1*) 

(Reference gp) 1 1 1 (Reference gp) 1 1 1 * Adj 1, adjusted for ... 
Appendix B. Sample data extraction forms 

Animal and in vitro studies 

B-6

Animal and In Vitro Studies

Author, Year 

Central hypothesis/Stated Purposes of Study Hypothesis diagram Experimental diets or reagents Control diets or reagents Study characteristics Country: 

Funding source: 

Gap in Knowledge Known: 

Unknown: 

Experimental model Study design Final sample size Duration Measurements / Endpoints / Outcomes of interest Other outcomes reported Results Authors’ Conclusions Quality Limitations / Comments 
Appendix C. Evidence Tables 

B Vitamin Evidence Tables – Animal / In Vitro Studies 

C-1 

Appendix C. Evidence Tables 

B Vitamin Evidence Tables – Animal / In Vitro Studie
Appendix C. Evidence Tables 

B Vitamin Evidence Tables – Animal / In Vitro Studies 

C-2 

Thiamine Author, Year Jolicoeur, 1979 (2 publications) 

Central hypothesis/Stated Purposes of the study 

To devise a standard battery of tests capable of quantitatively characterizing ataxia in the laboratory rats 

Hypothesis diagram Thiamine deficiency Æ ataxia indicated by lower performances on a standard battery of tests Experimental diets or reagents 

Thiamine-free diet (ICN Life Sciences, Nutritional Biochemical) 

Control diets or reagents Standard rat chow (Purina Rat Chow) in daily rations equivalent to the amounts consumed by the thiaminStudy characteristics Country: Canada 

Funding source: Conseil de la Recherche en Sante du Quebec and the Medical Research Concil of Cana

Gap in Knowledge Known: Chronic deficiency of vitamin B1 results in pervasive metabolic and biochemical alterations in the 

deficiency induces a peripheral neuropathy of the “dying back” type which involves both sensory and mrats are chronically fed a thiamine-free diet, a variety of disturbances such as anorexia, poloerection, t

ataxia develop at about 30-40 days from the start of the diet. 

Unknown: Standard method and procedure for detecting and measuring ataxia in experimental animals h

Experimental model Male Sprague Dawley rats, 275-350 g in weight Study design Parallel experiment-controlled study Final sample size Control: 6 Thiamine-free: 6 Duration 44 days Measurements / Endpoints / Outcomes of interest 

Locomotor activity: spontaneous locomotor activity was measured for 3 minutes by means of a photocell aCatalepsy: Intensity of catalepsy was determined by placing the animals’ front paws on a horizontal bar (1 

10 cm above the table. Time spent in the position, up to a maximum of 60 seconds, was recorded. 

Rigidity: the rat was suspended by its front paws grasping a metal rod (0.5 cm diameter) which was held b

50 cm above the table. The time the animal remained on the bar (maximum 60 sec) was recorded. 

Landing foot spread: After staining the handpaws with ink, the animal was held horizontally 30 cm above 

absorbent paper. The rat was dropped and the distance between the prints of each hindlimb was meas

Gait analysis: After staining the hindfeet with ink, the animal was walked through an enclosed 90 cm long 

covered floor. When 2 consecutive strides were obtained, the stride width, length and angle between ccontralateral sides were calculated. 

Reflexive responses: The presence of the righting and corneal reflexes as well as of a normal reaction to 

Other outcomes reported Results Statistical analysis indicated that only transient and sporadic effects were produced during initial phase (d

of the thiamine deficiency (TD). On day 21, TD animals displayed significantly less locomotor activity t

significant decrease in locomotion was also found on day 33 but not on day 27. The gait angles and wwere respectively decreased and increased on day 27 while length of stride was unchanged. On day 3

significantly decreased in TD rats but the other 2 gait parameters remained unaffected. 

During days 35 to 44, all TD animals lost the righting reflex, displayed impaired weight shift responses, an

effects were not seen in pair fed controls. No significant group differences group differences were foun

rigidity, and landing foot spread. Also, aside from the righting reflex and weight shift responses, no othin TD animals. Finally, gait analysis revealed that in TD rats the angle and length of strides were signif

of pair fed controls. 

Authors’ Conclusions Thiamine deficiency did not yield similar neurobehavioral effects as acrylamide- or 3-acetyl pyridine-induc
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Animal / In Vitro Studies 

C-3 

righting reflex and weight shift response were similarly affected by both TD and pyrithiamin treatment. components of gait were disturbed in both TD animals. 

Quality B Limitations / Comments Purina rata chow was not an appropriate control diet. The composition of diets prepared using crude mate

fluctuate from a batch-to-batch. Thus, it is difficult to obtain reproducible data. 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Animal / In Vitro Studies 

C-4 

Thiamine

Author, Year Zimitat, 1990 

Central hypothesis/Stated Purposes of Study 

To differentiate between the contributions of alcohol consumption and thiamine deficiency to the p

encephalopathy. Evaluate acute neurological disease by histology. 

Hypothesis diagram EtOH +/- Thiamine deficiency Æ Wernicke’s encephalopathy Experimental diets or reagents 1. Thiamine fortified: purified solid diet, thiamine 50 mg/Kg, water to drink 

2. Thiamine fortified/EtOH: purified solid diet, thiamine 50 mg/Kg, 15% EtOH in water (ad lib) 

3. Thiamine deficient: purified solid diet, thiamine 0 mg/Kg (implied), water to drink 4. Thiamine deficient /EtOH: purified solid diet, thiamine 0 mg/Kg (implied), 15% EtOH in water (ad 

Control diets or reagents Cereal based solid diet, thiamine 8 mg/Kg, water to drink Study characteristics Country: Australia 

Funding source:Government 

Gap in Knowledge Known: Wernicke’s encephalopathy associated with both thiamine deficiency and EtOH abuse 

Unknown: The independent effects of thiamine deficiency and EtOH on neuropathology 

Experimental model Wistar rats, 9 wk, female (6/cage, light/dark cycle 12 hr each, 23° C, mesh floors and feeders was

coprophagy and fecal contamination) 

Study design Divided into 5 diet groups. Evaluated 3x/wk for food and fluid intake, clinical signs of neurological d

either when displayed signs of opisthotonus and were moribund (thiamine deficient) or at age 4

Final sample size Clinical evaluation/Brain histopathology: 

Thiamine fortified: 12/6; Thiamine fortified/EtOH: 12/6; Thiamine deficient: 18/5; Thiamine deficient

Duration 35 wk Measurements / Endpoints / Outcomes of interest 

Ataxia; Opisthotonus; Moribund state or death; Brain pathology 

Other outcomes reported Diet intake, weight gain, brain weight and volume, biochemistry Results Control and thiamine fortified rats showed no signs of clinical disease. Starting at 5-10 wk, all thiam

eventually developed ataxia, opisthotonus, and moribund state. 

Control and thiamine fortified rats: 1 in each group had brain hemorrhage, rest had no abnormality 

Thiamine deficient rats: 4/11 had no abnormality, 7 had hemorrhages, of which 3 had necrosis 

had vacuolation. Pathologies seen primarily in the medial vestibular nucleus 

Authors’ Conclusions Symptoms and pathology due to thiamine deficiency (not EtOH). (Symptoms and pathology due to 

exacerbated and hastened by EtOH.) 

Quality B Limitations / Comments ? of value for age-related neurodegenerative disease 

Primary purpose of study is to investigate Wernicke’s encephalopathy. However, comparison of Et

included here. 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Animal / In Vitro Studies 

C-5 

Thiamine

Author, Year Terasawa, 1999 

Central hypothesis/Stated Purposes of Study 

To evaluate the influence of thiamine on learning ability of rats. 

Hypothesis diagram Thiamine Æ role in nervous function Æ learning ability Experimental diets or reagents 

Modified AIN-76 with thiamine HCl 30 mg per 100 g 

Control diets or reagents Modified AIN-76 with thiamine HCl 60 mg per 100 g (normal intake) Study characteristics Country: Japan 

Funding source: Government 

Gap in Knowledge Known: Thiamine plays a role in nervous function, possibly as part of nerve Na channel 

Unknown: Thiamine effect on learning 

Experimental model Wistar rats, weighing either 260-300 g 

Electrodes placed in periaqueductal gray matter. Trained to press lever to stop electrical stimulation (whic

behavior) 

Study design While on normal diet taught to stop electrical stimulation by pressing a lever positioned in an L maze. One 

Then divided into 2 groups, one continuing normal diet, other given low thiamine diet. 

Final sample size 5 in each group Duration ~42 days after start of low thiamine diet (until rats stopped responding to stimulus) Measurements / Endpoints / Outcomes of interest 

Response time: Time from start stimulation until start action (escape behavior) Running time: Time from start action until presses lever Task completion time: Response time + Running time 

Other outcomes reported none Results Normal thiamine rats: Response time, Running time, and Task completion time all remained over time. 

Low thiamine rats:  Response time: For about 3 weeks, remained stable, then progressively slowed until stopped respond

 Running time: Similar pattern to response time; running time began to slow after response time slowed

became more likely to get to lever but not press it. 

Authors’ Conclusions Response and running times slowed in thiamine deficient rats. Response time became longer first, then rQuality C Limitations / Comments Poor description of experiment. It appears that rats in normal thiamine group evaluated over whole time p

dividing into groups and phase 2 after division) while rats in low thiamine group analyzed only in phase experiment testing loss of learning or loss of motor function, since learning done prior to deficiency and cognitive function. 

Experiment comparing blood thiamine levels in rats without electrode implantation, with electrode but no trainin

with training is not included here. 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Animal / In Vitro Studies 

C-6 

ThiamineAuthor, Year Ciccia, 2000 

Central hypothesis/Stated Purposes of the study 

Ethanol and thiamine deficiency (TD) act synergistically, producing more severe clinical neurological distu

memory impairments than either TD or chronic ethanol alone 

Hypothesis diagram Ethanol + TD Æ more severe clinical neurological disturbances and cognitive and memory impairments th

ethanol alone [For the purpose of this report, we only focus on the comparison of TD vs. control diet] 

Experimental diets or reagents 

Animals were treated as control animals except during the 3 episodes of TD, each of which lasted approx

Beginning at weeks 10, 18, and 26 of treatment, the animals were exposed to a bout of TD. During ea

were fed ad libitum thiamine-deficient chow (Harlan Tekland, Madison, WI) and received intraperitonea

times weekly. Each bout of TD was ended by administration of a single dose of thiamine (100 mg/kg b

intraperitoneally) and restoration of regular chow. 

Control diets or reagents All animals received ad libitum vitamin-fortified chow and water and were given thiamine (1 mg/kg intrape

week (Monday, Wednesday, Friday) 

Study characteristics Country: US 

Funding source: No data 

Gap in Knowledge Known: The prolonged and heavy consumption of ethanol has been associated with a wide range of cogn

induce white matter and more subtle gray matter damage without damaging mamillary bodies. 

Unknown: Cognitive impairments in chronic alcoholics may be caused by a synergistic interaction betwee

Experimental model Male Sprague Dawley rats approximately 2 months of age at the start of the study Study design Paralleled experiment-controlled study Final sample size Control: 14 TD:12 Duration 8 months (including 3 times TD periods; each TD period lasted about 4.5 weeks) Measurements / Endpoints / Outcomes of interest 

Behavioral testing: spontaneous activity, spontaneous alternation, nonmatching-to-position (NMTP), delay

learning of matching-to-position (MTP), delayed MTP, and reversal learning of NMTP 

Clinical observations 

Other outcomes reported Body weights Results Behavioral testing: 

At different stages of behavioral testing, 5 control rats and 2 TD rats either died of unknown causes or 

were killed. Thus, group sizes reported on each behavioral task are different. 

There was no significant differences in the response time of spontaneous activity between TD and con

For spontaneous alternation, the TD group (n=13) made more perseverative choices than the CT grou

did not reach statistical significance. No significance differences were observed in the percentage obetween the groups. 

For NMTP acquisition trials, the average performance of all groups was well above chance on the first 

accuracy on session 5. Analysis of the group performance across session 1 through 5 revealed a sbut no significant treatment effect. All of the TD (n=12) and control (n=13) animals reached criterion 

For delayed NMTP trials, there was no difference in the performances on delayed NMTP trials betwee

(n-=13) animals. 

For first reversal learning MTP, despite extensive training, 1 TD rat failed to reach criterion and all con

criterion within the maximum 30 sessions of training. Analyses of the performance of animals that d

show any significant difference between TD and control animals. 

For delayed MTP trials, the accuracy of the TD group was near chance at the 120 sec delay, whereas 

accuracy was close to 70%. TD animals (n=10) performed significantly lower than controls on 120 s(p<0.0001) 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Animal / In Vitro Studies 

C-7 

For second reversal learning, all of the control and TD animals successfully relearned the NMTP task w

of sessions. There was no significant difference in accuracy over the initial 16 sessions between th

For task failure, no control animals failed to meet criterion for each behavioral task while TD animals h

9%. 

Clinical observations: 

During the course of each bout of thiamine deficiency, animals in TD group developed several clinical 

loss, slowed activity, ataxia, opisthotonos, and impaired righting reflex. 

There were no clinical signs of neurological or behavioral disturbances in any group when fed the thiam

Authors’ Conclusions About 3 months after cessation of TD treatment, the TD rats had significantly impaired on the long (120 s

trials. The observation suggest that repeated episodes of TD treatment produced impairment of workin

because we did not provide pair-fed controls for TD treatment, it is possible that working memory defic

by caloric reductions rather than the specific effects of TD toxicity. 

Overall results of the present study demonstrate that TD produced significant learning impairments on the 

discrimination tasks. However the percentage of TD animals that demonstrated learning deficits was re

Quality B Limitations / Comments There are no pair-fed controls for TD treatment, it is possible that working memory deficits may have been 

reductions (TD rats had significantly less weight at the end) rather than the specific effects of TD toxici
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Animal / In Vitro Studies 

C-8 

B6 Author, Year Tunnicliff et al., 1972 

Central hypothesis/Stated Purposes of the study 

Increased pyridoxal-5’-phosphate (PLP) concentration might lead to increased stability of some behav

observed as decreased in variance in behavioral variability in animals of uniform genetic constitutio

Hypothesis diagram Dietary B6 Æ ↑ PLP Æ ↑ stability of some behaviors Experimental diets or reagents 

Group 1: average 3 μg of pyridoxine HCL a day 

Group 2: average 15 μg of pyridoxine HCL a day 

Group 3: average 150 μg of pyridoxine HCL a day The amount of B6 was estimated based on each animal drank approximately 5ml of water and ate abo

Control diets or reagents None Study characteristics Country: US 

Funding source: Office of Education, Department of Health, Education and Welfare; National Institute o

and Stroke, NIH 

Gap in Knowledge Known: Vitamin B6 is the precursor of PLP. There is good evidence that pyridoxine in the diet is event

the brian. There is accumulating evidence that dietary vitamin B6 levels can influence behavior. 

Unknown: Decreasing levels of PLP may result first in its selective unavailability as a cofactor for some 

neurotransmitter metabolism. It might, therefore, be expected that levels of performance should be certain behaviors under specific dietary conditions. 

Experimental model C57BL/6J and DBA/2J inbred strains of mice (9 weeks old). These 3 inbred populations of mice have b

certain behavioral measures, including open-field activity. 

Study design Tested over 5 successive days for 5 min a day in the open-field for locomotor activity, then over a furth

escape learning, and finally they were tested for passive avoidance learning 

Final sample size 50 male animals in each strain were used for the experiments. 

Group 1: 15 Group2: 20 Group 3: 15 

Duration On diet for 4 weeks Measurements / Endpoints / Outcomes of interest 

1. locomotor activity 2. active escape learning 3. passive avoidance learning 

Both the mean scores and the variances were computed for each of the 3 behavioral tests 

Other outcomes reported Glutamic acid decarboxylase in brain Results Of the 3 tests, only locomotor activity in the open-field is affected by the dietary pyridoxine. 

For locomotor activity, no significant difference in mean scores, but variances in all 3 dietary groups we

from each other: 

Group 1 compared to group 2 (p<0.01) Group 2 compared to group 3 (p<0.001) Group 1 compared to group 3 (p<0.01) Variance was greatest in group 2 (15 μg of pyridoxine HCL) and least in group 3 (150 μg of pyridoxine 

Authors’ Conclusions A specified diet has an effect on behavioral variability. Since both the inbred strains of mice were equa

B6 diets, authors conclude that the response is not the result of some peculiar genetic defect, but is biochemical systems fundamental to the organism. 

Quality B Limitations / Comments No explanation why groups were unbalanced. No control animal 

Unable to explain a decrease in variances in those animals on the low pyridoxine diet. 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Animal / In Vitro Studies 

C-9 

B6 Author, Year Driskell, 1973 

Central hypothesis/Stated Purposes of the study 

To assess the value of behavioral measurements, brain pyridoxal phosphate, nucleic acid and protein con

alanine aminotransferase activities as criteria in establishing the vitamin B6 requirement of weanling a

rats 

Hypothesis diagram Inadequate vitamin B6 intake Æ impairments of behavioral measurements Experimental diets or reagents 

The basal diet supplemented with 15, 30, 45, 60, 75, or 90 μg pyridoxine per 15 g diet 

Control diets or reagents A Basal diet containing: (in %) vitamin-free casein, 15, sucrose, 29, cornstarch and vitamin mix, 34.88, ce

(15) salt mixture, 4, hydrogenated fat, 10; L-methionine, 0.08, L-cystine, 0.04, and corn oil with vitamin

Study characteristics Country: US 

Funding source: No data 

Gap in Knowledge Known: Vitamin B6 is needed in prenatal growth particularly by the central nervous system. The brain com

during the prenatal period; its maturation is completed early in life. 

Unknown: 

Experimental model Virgin mature female rats weighing approximately 220 g Study design Randomized controlled trial Final sample size Control: 6 

B6 15, 30, 45, 60, 75, or 90 μg/15 g diet: 6, 6, 6, 6, 6, 6 respectively 

Duration 3 weeks Measurements / Endpoints / Outcomes of interest 

Activity and curiosity: Animals were tested in a runway measuring 85 cm long and 23 cm wide. Phtoelectr

midpoint counted the number of times the animal traversed the runway (activity). A small metal object 

3.8 cm in diameter was electrically isolated from the floor such that simultaneous contact of the object 

count (curiosity). Animals were tested during 15-minute intervals on 14 consecutive days. 

Learning: T maze with water as a reinforcer. Measures obtained were correctness of response choice and 

beginning of a trial to choice by the animal). 

Emotionality: Fecal boli were counted for each animal during all testing sessions. 

Other outcomes reported Brain composition, including pyridoxal kinase activity, pyridoxal phosphate content, RNA and DNA analys

Erythrocyte alanine aminotransferase activity 

Results For sexually mature rats only, curiosity responses were significantly lower in the groups receiving 15 (p<0

vitamin B6 daily than in animals receiving higher levels. There is no difference in the curiosity between 

75, and 90 μg of vitamin B6 daily. 

For sexually mature rats only, the 15 and 30 μg of vitamin B6 daily groups had significantly lower activity 

animals on the higher pyridoxine levels. There is no difference in activity scores between animals rece

of vitamin B6 daily. 

There were no significant differences in maze performance among the dietary groups in sexually mature r

Authors’ Conclusions The data obtained in this study indicated that the rat required an intake of 30 to 45 μg of vitamin B6 daily 

stabilized level of activity and curiosity. 

A simple learning task, as exemplified by the T maze data obtained in this study, reflected no significant d

dietary groups. 

Quality A Limitations / Comments For the purpose of our report, we only look at the outcomes for sexually mature rats 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Animal / In Vitro Studies 

C-10 

B12 Author, Year Masuda, 1998 Central hypothesis/Stated 

Purposes of the study 

The effects of egg PC combined with vitamin B12 on memory of nucleus basalis magnocellularis (NBM) le

water maze task, and on choline or ACh concentrations in the brain of NBM lesioned rats 

Hypothesis diagram PC + vitamin B12 Æ ↑choline or Ach in the brain of NBM lesioned rats Æ ⁭ water maze performances Experimental diets or 

reagents 

PC group: control diet plus 10 g/kg of egg yolk PC (PL-100LE, 92% PC; Q/P/ Corp., Tokyo) Vit B12 group: control diet plus 1.0 mg/kg of vitamin B12 (Sigma) PC+Vit B12 group: control diet plus 10 g/kg of egg yolk PC and 1.0 mg/kg of vitamin B12 Egg PC and Vitamin B12 which were dissolved in water were administered orally using intragastric tube fo

(for inducing NBM lesions) 

Control diets or reagents 20% casein diet, containing protein (casein: 200 g/kg), carbohydrate (corn starch and sucrose: 675 g/kg), 

(cellulose powder: 20 g/kg), mineral mix (40 g/kg), vitamin mix (10 g/kg), DL-methionine (3 g/kg) and c

Study characteristics Country: Japan 

Funding source: No data 

Gap in Knowledge Known: Acetylcholine (Ach) is an essential neurotransmitter which plays a role in learning and memory. In 

change of neurotrasmitters is the decrease of Ach, especially in the cerebral cortex. Several studies habrain choline and Ach contents in rodents. The problem is that learning and memory were not evaluate

Unknown: The effects of phosphatidylcholine (PC) combined with vitamin B12 on memory of rats. 

Experimental model Male Wistar rats weighing 250-300 g with NBM lesion (one of the animal model which mimics some of the 

and memory loss associated with Alzheimer’s disease) 

Study design Paralleled experiment-controlled trial Final sample size SHAM-Ctrl: 10 NBM-Ctrl: 10 NBM-B12: 10 NBM-PC: 10 NBM-B12+PC: 10 Duration 10-18 days, depending on experiments Measurements / Endpoints 

/ Outcomes of interest 

Spontaneous movements were measured by Animex counter (AUTOMEX II, Columbus Instruments) for 1

days after surgery 10-12 

Morris water maze task: on day 14 after surgery, water maze task was carried out. All animals were traine

(during days 14, 15, 16 after surgery) 

Spatial probe (Retention): the next day after acquisition test (on day 17 after surgery), were removed the p

rats to swim for 60 sec. The time spent in the west quadrant where the platform had been located durin

Other outcomes reported Brian choline and Ach concentrations Results There was no significant difference in spontaneous movements of rats between groups. 

Worris water maze: 

- Acquisition: 

The unlesioned SHAM-ctrl group had significantly shorter latencies than the NBM-ctrl group for 3, 4 

NK). NBM-ctrl group remained learning deficit and required 20-30 sec to find the platform, even 

Latencies of acquisition in NBM-12 group was not statistically different from that of the NBM-ctrl gro

- Spatial probe (Retention): 

In NBM lesioned rats, the time spent in the platform-quadrant was significantly shorter than that in t

(p<0.01, NK) 

Times of the NBM-B-12 group was not statistically different from that of the NBM-ctrl group. 

Authors’ Conclusions Low dose (1 mg/kg) of vitamin B12 alone did not recover the depletion of choline and Ach concentrations 

did not improve memory of NBM lesioned rats. If shortage of choline in the frontal cortex markedly occ

activation of choline acetyltransferase by vitamin B12 may not be useful for ACh synthesis. 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Animal / In Vitro Studies 

C-11 

Quality A Limitations / Comments For the purpose of this review, only results from the comparisons of Vit B12 to control groups are conside

Vitamin B12 is usually included 0.05 mg/kg diet (equivalent to about 0.001 mg/kg) in the standard stock d

Vitamin B12 was dissolved in water were administered orally using intragastric tube, and the duration of in

short. 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Animal / In Vitro Studies 

C-12 

Folate Author, year Duan, 2002

Central hypothesis/Stated Purposes of the study 

By increasing Homocysteine (Hcy) levels, folate deficiency endangers dopaminergic neurons thereby incr

Parkinson’s disease 

Hypothesis diagram Folate deficiency Æ ⁭ Hcy Æ dysfunction and death in dopaminergic neurons Æ PD Experimental diets or reagents 

Folate deficient diet (FD diet): diet lacked folate, but was otherwise identical to the control diet. 

Control diets or reagents Standard mouse diet (Dyets, Inc.; diet #518754) which contained 2 mg folate/kg of food. Study characteristics Country: US 

Funding source: ND 

Gap in Knowledge Known: PD is characterized by dysfunction and degeneration of dopaminergic neurons in the substantia n

progressive akinesia, tremor and rigidity. Recent findings suggest the Hcy levels are increased in PD p

Unknown: Whether or not folate deficiency and/or elevated Hcy levels play a critical role in the pathogene

Experimental model The toxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) induces PD-like pathology and behavioral 

month-old male C57B1/6 mice weighing 21-23 g 

Study design After 3 months dietary treatments, both experiment and control animals (5-month old mice) received eithe

MPTP/kg body weight, separated by 4 hours, a regiment that resulted in no detectable pathology or sy

injections. Behavior testing for motor function was assessed 1 week later. 24-hr later, mice were killed 

removed; the striata were removed and stored at –80 °C until used for measurements of monoamines 

Final sample size FD diet – MPTP 10 FD diet – Saline 10 

Ctrl diet – MPTP 10 Ctrl diet – Saline 10 

Duration 3 months Measurements / Endpoints / Outcomes of interest 

Motor performance was assessed with a rotary rod apparatus. Both the total time spent on the rotating rod 

falls for each mouse were recorded 

Number of dopaminergic neurons in substantia nigra: counted TH immunoreactive neurons in the substan

mouse 

Other outcomes reported Plasma Hcy levles 

Levels of tyrosine hydroxylase (TH; an enzyme required for dopamine synthesis) in the striatum 

Results Folate deficiency alone did not impair performance on rotarod tests. There was no significant difference in 

in the number of falls between animals on folate deficient diet and those on control diet. Folate deficienstriatal TH levels nor numbers of TH-positive neurons in the SN. 

FD diet + MPTP injection Æ marked decrease in TH levels in the striatum; marked 50-60% loss of dopam

(p<0.01) Æ significant decrease in time on the rotarod (p<0.01); significant increase in the numbers of 

Authors’ Conclusions In contrast to mice on the control diet that were resistant to the subtoxic dose of MPTP, mice that had bee

folate-deficient diet exhibited profound motor dysfunction as indicated by a decrease in the time period 

themselves on the rotarod and by an increased numbers of falls. 

Quality A Limitations / Comments 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Animal / In Vitro Studies 

C-13 

FolateAuthor, Year 

Kim, 2002 

Central hypothesis/Stated Purposes of Study 

To investigate the effects of folate deprivation on plasma homocysteine, and its cerebrovascular and neur

hyperhomocystinemia in rats by folate deprivation and examined the morphological alterations in cerebelectron microscopy 

Hypothesis diagram Experimental diets or reagents 

Folate deficient diet (folate-D): Diet #31; Samtaco without added folate 

Control diets or reagents Folate-supplemented diet (folate-S): Diet #31; Samtaco adding 0.004 g folate/kg diet Study characteristics Country: Korea 

Funding source: Government 

Gap in Knowledge Known: 

Unknown: 

Experimental model Male Sprague-Dawley rats (6-mo-old) (Samtaco, Osan, Korea Study design Paralleled experimental-control trial, blinded analyses Final sample size 8 per group Duration 8 weeks Measurements / Endpoints / Outcomes of interest 

Electron microscopic findings for cerebrocortical microvascular wall in brain cross sections 

Other outcomes reported Weight gain, food intake, plasma homocysteine levels Results Rats fed folate-S diet (control) showed a normal cerebral capillary wall with a relatively smooth luminal su

layer of basement membrane around the endothelium, surrounging a pericyte. 

A degenerative appearance of the cerebrocortical microvascular wall was shown in rats fed folate-D diet. 

mitochondrial swelling (m) with disintegration of mitochondrial cristae and dissolution of cytoplasmic or

cell cytoplasm are exhibited. Abnormal electron-lucent structures indicating perivascular amorphous fib

the basement membrane and in the perivascular area. Locally and irregularly thickened basement mem

cerebral microvessels of folate-deficient rats. Frequent perivascular detachment was observed in relatimicrovessels. Characteristic degenerative pericytes including mitochondrial and cytoplasmic swollen p

Authors’ Conclusions Quality A Limitations / Comments The folate-S diet is considered “standard diet” or control diet. 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Animal / In Vitro Studies 

C-14 

FolateAuthor, Year Kruman, 2002 

Central hypothesis/Stated Purposes of the study 

Folate deficiency and Hcy sensitize neurons to Aβ-induced death 

Hypothesis diagram Folate deficiency and Hcy Æ increase Aβ-induced death of hippocampal cells Æ Increase risk of AD Experimental diets or reagents 

Diet lacked folate and contained 4.5 gm/kg D,L-homocysteine (Dyetes Incorporated; diet 518806) 

Control diets or reagents Standard mouse diet that contained defined choline and folate and lacked D,L-homocysteine (Dyets, Inco

diet 518754) 

Study characteristics Country: US 

Funding source: No data 

Gap in Knowledge Known: In AD the death of neurons in brain regions critical for learning and memory is believed to result fr

and accumulation of insoluble forms of amyloid β-peptide (Aβ), which may endanger and kill neurons b

disrupting cellular ion homeostasis. DNA damage has been documented in association with neuronal dtissues of AD patients. Folate deficiency and homocysteine, which can impair DNA repair in non-neuro

Unknown: Whether folate deficiency and homocysteine can promote neurons to Aβ-induced death 

Experimental model 7-month-old amyloid precursor protein (APP) mutant mice. These mice develop age-dependent deposition 

which is first evident in the hippocampus and cerebral cortex beginning after 10 months of age. 

Study design 7-month-old APP mutant mice and littermate non-transgenic control mice were maintained on either a con

deficient diet. After 3 months on the diets, blood was taken and brains were removed. 

Final sample size No data Duration 3 months Measurements / Endpoints / Outcomes of interest 

ELISA and immuohistochemical analysis of Aβ production or deposition: ELISA for soluble and plaque-as

40 was performed 

Quantification of hippocampal pyramidal neurons: Nissl-possitive undamaged neurons were counted in th

pyramidal cell layer, including regions CA1 and CA3 (CA2 was included in counts for CA3) 

Other outcomes reported Homocysteine levels Results Levels of Aβ1-40 and Aβ1-42 were below the limit of detection in non-transgenic mice (data not shown), w

and 2 nmol/gm wet brain weight, respectively in APP mutant mice that had been maintained on either deficient diets, with no significant differences in levels of either Aβ species between mice on control or ratio Aβ1-42/ Aβ1-40 also was not changed by the folate-deficient diet. 

Examination of brain sections immunostained with an antibody against Aβ revealed no evidence of extrac

in APP mutant mice that had been maintained on either diet. 

The analyses in regions CA3 of hippocampus revealed a highly significant 20% loss of neurons in APP m

deficient diet compared with mutant mice on the control diet (p<0.0001); however, there was no differe

densities of neurons in region CA1 between the groups. 

Authors’ Conclusions Folate deficiency renders hippocampal CA3 neurons in APP mutant mice vulnerable to death by a mecha

increased Aβ production or deposition. 

Quality B Limitations / Comments The in vitro experiments in this article were excluded due to mixed folate and methionine deficient media u

No data on the numbers of animals per group 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Animal / In Vitro Studies 

C-15 

AD gene Author, Year Shea, 2002 [2964] 

Central hypothesis/Stated Purposes of the study 

Folate compensates for the diminished oxidative buffering capacity of brains of apoE deficient mice. 

Hypothesis diagram Beta-amyloid -> generalized oxidative damage -> neurodegeneration 

ApoE deficiency ?-> free Fe levels -> ↑reactive oxygen species Dietary folate deficiency -> ↑Hcy -> CNS oxidative damage and potentiates beta-amyloid and glutamate 

neurodegeneration 

Vitamin-free, basal diet (AIN-76) Fe challenge with Fe (ferric citrate 8 g/kg) [Vitamin E supplement (alpha-tocopherol, 50 IU/kg) not considered experimental diet here] 

Experimental diets or reagents 

 1. – Folate, + Vit E, – Fe  2. – Folate, – Vit E, – Fe 

3. – Folate, + Vit E, + Fe 4. – Folate, – Vit E, + Fe 

Control diets or reagents Vitamin-free, basal diet (AIN-76) supplemented with folic acid (4 mg/kg total diet wet weight) 

 1. + Folate, + Vit E, – Fe  2. + Folate, – Vit E, – Fe 

3. + Folate, + Vit E, + Fe 4. + Folate, – Vit E, + Fe 

Study characteristics Country: US 

Funding source: ND 

Gap in Knowledge Known: Folate deficiency leads to oxidative damage and neurodegeneration 

Unknown: The effect of folate on preventing oxidative damage in normal and ApoE deficient mice 

Experimental model 1. ApoEtmlUne homozygous knockout mice on a C57B1/6J background, 10-14 mo old 

2. Normal C57B1/6J mice, 10-14 mo old 

Study design Mice fed experimental or control diets for 1 month, after which total CNS tissue was harvested, homogen

according to total protein and aliquots of unfractionated homogenates were analyzed for TBARs 

Final sample size 12 mice per experiment Duration 1 month Measurements / Endpoints / Outcomes of interest 

TBARs, “an end-point index of oxidative damage”

Other outcomes reported Results 1. CNS of normal mice did not contain increased TBARS following Fe challenge in the presence or absen

2. ApoE knockout mice without folate had significantly increased TBARS when challenged with Fe. 3. ApoE knockout mice with folate did not have increased TBARs when challenged with Fe. 

Authors’ Conclusions The genetic deficiency of a complete absence of ApoE can be alleviated with folate repletion. This may p

explanation as to why certain ApoE alleles are associated with increased prevalence and earlier onse

100% penetrance. 

Quality A Limitations / Comments TBARs are a rough estimate only of oxidative damage. In this experiment they derived from a combinatio

oxidative damage. 

TBARs measured from whole CNS, not just key brain areas related to AD, such as hippocampus and corExperiment does not distinguish between cerebrovascular and neuronal oxidative damage. 

No “clinical” outcomes. 

ApoE, apolipoprotein E, CNS, central nervous system TBAR, thiobarbituric acid-reactive substances. 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Animal / In Vitro Studies 

C-16 

AD geneAuthor, Year Shea, 2002 [2966] 

Central hypothesis/Stated Purposes of the study 

Test hypothesis that deficiencies in ApoE function are associated with increased oxidative stress in Compare responses of transgenic mice lacking ApoE with those of normal mice to dietary oxidative 

dprivation (and by inclusion of excess iron within their diet). 

Hypothesis diagram ApoE deficiency ->↑ susceptibility to oxidative damage 

Dietary folate deficiency -> ↑Oxidative stress -> CNS oxidative damage 

Vitamin-free, basal diet (AIN-76) supplemented with folic acid (4 mg/kg total diet wet weight) Fe challenge with Fe (ferric citrate 8 g/kg) 

Experimental diets or reagents 

 1. + Folate, – Fe 2. + Folate, + Fe 

Control diets or reagents Vitamin-free, basal diet (AIN-76) 

 1. – Folate, – Fe 2. – Folate, + Fe 

Study characteristics Country: US 

Funding source: ND 

Gap in Knowledge Known: Folate deficiency leads to oxidative damage and neurodegeneration 

Unknown: The effect of folate on preventing oxidative damage in normal and ApoE deficient mice 

Experimental model 1. ApoEtmlUne homozygous knockout mice on a C57B1/6J background 

2. Normal C57B1/6J mice 

Study design Mice fed experimental or control diets for 1 month, after which total CNS tissue was harvested, hom

for measurements 

Final sample size 3-4 mice per diet per experiment Duration 1 month Measurements / Endpoints / Outcomes of interest 

1. TBARs 2. Total antioxidant activity in CNS homogenates in a cell-free assay 

Other outcomes reported Glutathione Results 1. ApoE-deficient mice had significantly increased TBARs when challenged with Fe in the absence 

ApoE-deficient mice challenged with Fe in the presence of folate and to normal mice, regardless 

2. Antioxidant capacity lower in ApoE-deficient mice receiving Fe in the absence of folate compared 

folate or compared to normal mice, regardless of folate status. 

Authors’ Conclusions In the setting of ApoE deficiency, mice are incapable of overcoming oxidative stress of Fe without fo

The combined influence of Fe challenge and folate deprivation depletes the antioxidant capacity of 

Quality A Limitations / Comments TBARs are a rough estimate only of oxidative damage. In vitro antioxidant capacity might not reflec

TBARs measured from whole CNS, not just key brain areas related to AD, such as hippocampus anNo “clinical” outcomes. 

ApoE, apolipoprotein E TBAR, thiobarbituric acid-reactive substances. CNS, central nervous system 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Animal / In Vitro Studies 

C-17 

AD geneAuthor, Year Shea, 2003 [2968] 

Central hypothesis/Stated Purposes of the study 

Deficiencies in ApoE function are associated with increased oxidative stress in CNS. This was carried out 

responses of transgenic mice lacking ApoE with those of normal mice of the identical genetic backgrou

stress induced by folate deprivation and by inclusion of excess iron within their diet. 

Hypothesis diagram 

Vitamin-free, basal diet (AIN-76) Fe challenge with Fe (ferric citrate 8 g/kg) 

Experimental diets or reagents 

 1. + Folate, – Fe 2. + Folate, + Fe 

Control diets or reagents Vitamin-free, basal diet (AIN-76) supplemented with folic acid (4 mg/kg total diet wet weight) 

 1. – Folate, – Fe 2. – Folate, + Fe 

Study characteristics Country: US 

Funding source: ND 

Gap in Knowledge Known: 

Unknown: 

Experimental model Normal C57B1/6J mice and ApoE homozygous knockout mice on a C57B1/6J background were maintain

basal diet with and without folic acid; and with or without iron. Homogenates of CNS were measured. 

Study design Mice fed experimental or control diets for 1 month, after which total CNS tissue was harvested, homogeni

measurements 

Final sample size Samples were derived from 3 to 4 normal and 3 to 4 ApoE -/- mice for each dietary condition, from 3 to 4 

(total n ≥ 12 for each diet for all 3 experiments) 

Duration Measurements / Endpoints / Outcomes of interest 

thiobarbituric acid-reactive substances (TBARs) as an index of endpoint oxidative damage 

Trolox equivalent antioxidant capacity 

Other outcomes reported glutathione level in CNS Results CNS of ApoE deficient mice demonstrated an approximate 20% increase in glutathione levels compared t

Individually, deprivation of folate and dietary iron each increased glutathione levels in CNS of both normal 

In combination, folate deprivation with dietary iron further increased glutathione levels in both normal However, CNS of ApoE-deficient mice displayed a markedly greater increase than did CNS of normal 

ApoE deficient mice displayed increased TBARs when challenged with dietary iron in the absence of folat

In the absence of any dietary challenge, CNS of ApoE -/- mice exhibited a significantly increased oxidative 

that of normal mice (p<0.05). 

ApoE deficient mice receiving iron in the absence of folate displayed less CNS antioxidant capacity than u

for these mice. 

Authors’ Conclusions 1. These findings demonstrate that ApoE deficient mice are less capable of buffering oxidative cha

mice. 

2. These findings also suggest that the increased levels of glutathione observed in CNS of ApoE de

dietary challenge with iron and folate deficiency were incapable of compensating for the lack of A

3. The lack of ApoE activity fostered an increase in one or more endogenous antioxidants. 4. Folate deprivation fostered an additonal increase in antioxidant in normal CNS. 5. Endogenous antioxidants were upregulated in CNS of both strains of mice in response to oxidati

6. The combined influence of iron challenge and folate deprivation depleted the antioxidant capcity 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Animal / In Vitro Studies 

C-18 

7. These data support the hypothesis that ApoE deficiency is associated with increased oxidative s

Quality A Limitations / Comments 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Animal / In Vitro Studies 

C-19 

AD gene

Author, Year Fuso, 2005 

Central hypothesis/Stated 

Purposes of the study 

The nutritional deficits could lead to Hcy/SAM metabolism alteration (hyper-homocysteinemia) with the con 

SAM levels. 

Alterations in SAM/Hcy cycle (producing Hcy accumulation) are responsible for decreased SAM (S-adenos

in turn, for reduced DNA methylation. 

Hypothesis diagram Folate and B12 deficient Æ Hcy cannot transform to SAM Æ ↑ Hcy and ↓ SAM Æ reduced DNA methylati

expression (such as amyloid precursor protein (APP) processing and ß-amyloid (Aß) production throug

Presenilin1 (PS1) expression) 

Experimental diets or 

reagents 

Deprive medium (DDM): It was prepared substracting folate and vitamin B12 from the preparation of F14 m

fetal calf serum plus 10μM retinoic acid. The residual folate and vitamin B12 concentrations were 60 an

These vitamin amounts derived only from the fetal calf serum (FCS) added to the medium. 

Control diets or reagents Differentiation medium (DM): F14 medium with 1% fetal calf serum plus 10 μM retinoic acid Study characteristics Country: Italy 

Funding Source: MIUR grants (Ateneo and FIRB 2003) 

Gap in Knowledge Known: Elevated Hcy plasma level is a serious risk factor for the onset of AD. Moreover SAM levels decre

generally, with aging. The great relevance of Aß production in AD is largely documented and acceptedof reducing this protein in the therapy. 

Unknown: Correlation between the SAM/Hcy cycle, DNA methylation and AD 

Experimental model 2 different neuroblastoma cell lines: SK-N-SH and SK-N-BE. Since the 2 lines gave similar results in all the 

we decided to show only the results relative to SK-N-BE cell line. 

Study design In vitro Final sample size 4 or 5 depending on experiments Duration N/A Measurements / Endpoints 

/ Outcomes of interest 

PS1 and PS2 expression APP expression 

Other outcomes reported Apoptosis, SAM production, γ- and ß-secretases (BACE) production Results Gene expression, compared DM to DDM media: 

There was no significant difference in APP expression between the 2 groups both at 48 and 96 hours (

PS1 expression was similar in DM while DDM induced high increase in PS1 expression (n=4, p<0.05). PS2 expression seems to be independent from the different experimental conditions, but with a little hig

APP. 

Protein expression, compared DM to DDM media: 

The 110-kDa APP isoform increased in DM and was more abundant after 144 hours in all the experime

nevertheless, there was no significant differences between DM and DDM cells (except for a decreas

p<0.05) (n=5). 

PS1 protein was synthesized at similar levels in DM while DDM induce an increase in PS1 synthesis (nPS2 synthesis seems to be independent from the experimental conditions. 

Authors’ Conclusions Complete and deprived medium as well as FCS were preliminarily analyzed in order to verify that folate an

really low. We think that such a partial vitamin deprivation from the medium, instead of a total depletion

a nutritional deficit. The HPLC analysis also allowed us to demonstrate that the intracellular SAM levels 

medium were lower respect to the complete medium; this findings confirmed that Hcy metabolism alter

vitamin B12 deprivation really caused the reduction of SAM levels in the cells. 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Animal / In Vitro Studies 

C-20 

We demonstrated that PS1 can be induced by folate and vitamin B12 deprivation. The other genes involve

APP itself seemed to be independent on medium deprivation. 

Quality A Limitations / Comments For the purpose of our review, the best comparison in this study is DDM vs. DM since the only differences 

media are the amount of folate and B12. Although growth medium (GM) is the control group in the orig

compare DDM to GM because there is no retinoic acid (or vitamin A) in GM. Furthermore, the results o

the effects of additional SAM in the media are not of interest. Since the authors’ primary purposes were 

of folate and B12 on the gene expression, the conclusions of the original study focused on the effect of 

media on the gene expression. 

All measurements were performed in duplicate. 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Animal / In Vitro Studies 

C-21 

Blood-brain barrier or cerebrovascular endothelial function Author, Year Warnock, 1968 

Central hypothesis/Stated Purposes of Study 

Using labeling patterns of glutamate to study pyruvate metabolism of normal and thiamine deficient r

Hypothesis diagram Pyruvate metabolism (to glutamic acid) that occurs in the liver or the brain result in different radiolabe

acid. Therefore, differences in glucose and pyruvate transport across the blood-brain barrier (BBB

different conditions. 

Gap in Knowledge Known: As above. Pyruvate does not directly enter the brain of adult animals. 

Unknown: BBB transport in thiamine deficiency 

Experimental diets or reagents Thiamine deficient diet Control diets or reagents Thiamine adequate diet Study characteristics Country: US 

Funding source: Government 

Experimental model Male rats, Sprague-Dawley, initial weights of 50-65 g. Study design Parallel experiment-controlled trial Final sample size Thiamine deficient: 15 

Normal diet: 10 

Duration nd. “At first signs of polyneuritis.” Measurements / Endpoints / Outcomes of interest 

Brain glutamic acid radiolabelling 10 minutes after injection with Na Pyruvate-2-14C and decapitation

 (If pyruvate is metabolized in the liver, brain glutamic acid would be labeled on carbon 4. If metab

glutamic acid would be labeled mainly on carbon 5.) 

Other outcomes reported Evaluation of rats given thiamine anti-metabolite oxythiamine. Results Pyruvate-2-14C entered the brain directly in adult thiamine deficient animals. Authors’ Conclusions Selective transport across BBB was not functioning in a normal fashion. Quality B Limitations / Comments Duration of thiamine deficiency not stated, although sufficient to cause symptoms. 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Animal / In Vitro Studies 

C-22 

Blood-brain barrier or cerebrovascular endothelial function Author, Year Robertson, 1971 

Central hypothesis/Stated Purposes of Study 

To test the hypothesis that the blood brain barrier (BBB) remains intact with respect to plasma prote

lesion associated with thiamine deficiency, but becomes permeable to protein in the necrotic stag

Hypothesis diagram Gap in Knowledge Known: Early stages of experimental thiamine deficiency causes intracellular edema in brainstem, w

evidence of parenchymal or vascular necrosis. 

Unknown: Whether early changes are due to a defect of transport of plasma proteins across the BBB 

deficiency. 

Experimental diets or reagents Synthetic thiamine-free diet (Nutritional Biochemical Corp) ad lib Control diets or reagents Same diet with thiamine HCl 40 μg/100 g body weight i.p. daily Study characteristics From day 28-46, bovine albumin conjugated with fluorescein isothiocyanate (FLA) or complexed with 

administered IV. Animals were killed 30 minutes later. Brainstem and cerebellum were analyzed sections. 

Brains were evaluated for both histology (degree of spongy edema, presence of congestion, hemorr

neuronal loss). Rats were then categorized into: 

Group A: Slight edema (n=10) Group B: More marked spongy reticulation, frequently accompanied by vascular congestion (n=14) Group C: Hemorrhages, tissue degradation and neuronal fallout. (n=22) 

Experimental model Immature female rats, Long Evans strain or Wistar Furth strain Study design Parallel, controlled study. Final sample size 56 analyzed Duration 28-46 days Measurements / Endpoints / Outcomes of interest 

Presence or absence of extravascular fluorescence in relation to the severity of lesion (n=46) 

Other outcomes reported Presence or absence of FLA or EBA in neural parenchyma (n=10) Results In control animals, specific fluorescence of the neuropil – that is, tissues beyond the vascular confine

Extravascular fluorescence was present in 1/24 rat brains from Groups A+B (n=24). Extravascular fluorescence was present in 12/22 rat brains from Group C (n=22). P<0.001 for difference. 

Authors’ Conclusions BBB is intact with respect to albumin in the early lesions of thiamin deficiency. Thus intracellular ede

deficiency results from a defect in cell membrane transport rather than a vascular leak of the inflaBBB. 

Quality B Limitations / Comments Initially included 134 rats. Controls were selected in every fifth animal. Rats that died spontaneously 

failures (n=5), or had technical failures (n=22) were not evaluated. No breakdown number for anievaluated per group. 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Animal / In Vitro Studies 

C-23 

Blood-brain barrier or cerebrovascular endothelial function Author, Year Manz, 1972 

Central hypothesis/Stated Purposes of Study 

To follow up on earlier experiment reported in Robertson, 1971. To further define the nature and sequence of permeability changes of the BBB, using horseradish per

Hypothesis diagram Gap in Knowledge Known: Early stages of experimental thiamine deficiency causes intracellular edema in brainstem, wit

evidence of parenchymal or vascular necrosis. These changes are not related to disrupted albumin BBB. 

Unknown: Other possible transport defects in BBB 

Experimental diets or reagents 

Synthetic thiamine-free diet (Nutritional Biochemical Corp) ad lib 

Control diets or reagents Same diet with thiamine HCl 40 μg/100 g body weight i.p. daily Study characteristics From day 30-45 of thiamine deficiency, horseradish peroxidase was administered IV. 1-6 hours later f

with glutaraldehyde and animals were killed. Brainstem was fixed and prepared. 

Brains were evaluated both histology (edema, hemorrhage, necrosis) and under both light and electro

peroxidase granules. Rats were then categorized into: 

Group A: edema only (n=7) Group B: hemorrhage and necrosis. (n=30) 

Experimental model Immature female rats, Wistar Furth strain Study design Parallel, controlled study. Final sample size 49 analyzed (37 treated, 12 controls) Duration 30-45 days Measurements / Endpoints / Outcomes of interest 

Parenchymatous infiltration with horseradish peroxidase (HRP) 

Other outcomes reported Results Under light microscopy 12 control rats and the 7 Group A rats had “qualitatively and quantitatively” the 

peroxidase granules in phagocytes. 

 Among the 30 Group B rats, 21 had a diffuse parenchymatous infiltration of the vestibular area, ge

unreported number had numerous large plump phagocytic cells within the vestibular area; 9 had lin

product along the course of vessels. 

 0/7 Group A rats had parenchymatous infiltration, 21/30 Group B rats did; P<0.001 Under electron microscopy, control rats and Group A rats were devoid of peroxidase in the vascular b

the neural parenchyma. In Group B rats, the interendothelial junctional complexes were morphologically intact; reaction procontraluminal side basement membrane zone of intercellular gaps. 

Authors’ Conclusions Confirms timing of BBB competence from Robertson 1971 study. 

BBB damage seen in later stages corresponds to damage seen from cold-injury edema and other moLeakage appears to be predominantly through the mechanism of pinocytosis (introduction of fluids int

the cell membrane, followed by formation of vesicles within the cells), not disruption of interendoth

This may be due to the fact that thiamine is a necessary cofactor for several enzymes required for act

membranes. 

Quality A Limitations / Comments Initially included 99 rats. Rats that died spontaneously (n=21) or presenting technical difficulties (n=29
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Animal / In Vitro Studies 

C-24 

Blood-brain barrier or cerebrovascular endothelial function Author, Year Lee, 2004 

Central hypothesis/Stated Purposes of Study 

To clarify the effects of hyperhomocysteinemia on cerebral endothelial function and elucidate possible me

induced vascular and neuronal toxicity. 

Hypothesis diagram Experimental diets or reagents 

HF diet: AIN93M diet modified to contain folic acid and homocystine (Hcy): 0.3% Hcy and 0.008 g/kg folat

Control diets or reagents H diet: AIN93M diet modified to contain 0.3% Hcy Study characteristics Country: Korea 

Funding source: Government 

Gap in Knowledge Known: Folate supplementation has proven to be effective in treating hyperhomocystinemia and endothel

Unknown: The cerebrovascular effects of homocystine and folate supplementation are poorly understood 

Experimental model Male Sprague-Dawley rats (8 weeks old) (Samtaco, Osan, Korea) Study design Paralleled experimental-control trial Final sample size Duration 2 weeks Measurements / Endpoints / Outcomes of interest 

Cerebral expression level of two markers for endothelial dysfunction: the glucose transporter protein (GLU

adhesion molecule (VCAM-1) 

Endothelial nitric oxide synthase (eNOS): Samples of the brains were analyzed by Western blotting techn

Other outcomes reported Plasma Hcy, vitamin B12 and folic acid 

Weight gain, food intake, food efficiency ratio 

Results When the rats with induced hyperhomocysteinemia received 2 weeks of dietary folate supplementaion wit

the level of brain eNOS protein expression increased by 43.5±5.4% (p=0.04) compared to the 4 week hgroup). The increase is in good agreement with the 27.4±2.7% (p=0.04) increase in the GLUT-1 level a

(p=0.04) decrease in VCAM-1 level. 

Note: No significant difference in weight gain, food intake or food efficiency ratio between animals on HF a

Authors’ Conclusions This study shows that hyperhomocysteinemia induces endothelial dysfunction, characterized by reduced e

concomitant changes in the VCAM-1 and GLUT content in the rat brain. In addition, these effects were 

by dietary supplementation with folate. To our knowledge, this is the first morphological study to demon

effects of dietary folate on hyperhomocysteinemia-induced cerebral endothelial dysfunction in vivo. 

However, in the course of this study, an unexpected result was observed in the cerebral content of the VC

fed animals (group H) – this was reduced rather than increase. The cause of this unexpected result for under investigation. 

Quality A Limitations / Comments Rats in folate diet group were fed a diet with Hcy for 2 weeks before changed to folate-supplmented diet. T

were fed a diet without folate or Hcy for 2 weeks and then continued for another 2 weeks. For the purpcomparison is not appropriate. 
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Blood-brain barrier or cerebrovascular endothelial function Author, Year Lee, 2005 

Central hypothesis/Stated Purposes of Study 

To evaluate the effects of 8 weeks of dietary folate supplementation on cerebral vascular damage induced 

hyperhomosysteinemia in vivo, in particular investigating the structural features of the cerebral vascula

microscopy. 

Hypothesis diagram Experimental diets or reagents 

HF diet: AIN93M diet modified to contain folic acid and homocystine (Hcy): 0.3% Hcy and 0.008 g/kg folat

Control diets or reagents H diet: AIN93M diet modified to contain 0.3% Hcy Study characteristics Country: Korea 

Funding source: Government 

Gap in Knowledge Known: Folate supplementation has proven to be effective in treating hyperhomocystinemia and endothel

Unknown: The cerebrovascular effects of homocystine and folate supplementation are poorly understood 

Experimental model Male Sprague-Dawley rats (8 weeks old) (Samtaco, Osan, Korea) Study design Paralleled experimental-control trial Final sample size 4 per group Duration 8 weeks Measurements / Endpoints / Outcomes of interest 

Cerebral expression level of the glucose transporter protein (GLUT-1) Ultrastructural alterations in cerebral vasculature and % of damaged vessels: electron microscopy 

Other outcomes reported Plasma TBARS, Hcy, vitamin B12 and folic acid 

Weight gain, food intake, food efficiency ratio 

Results 8 weeks of folate supplementation significantly increased the cerebral GLUT-1 protein, which had been de

diet for 2 weeks and for 10 weeks (p<0.05) 

In the folate supplemented group damaged vessels such as annihilation of cell organelles, degeneration o

and perivascular detachment were also observed. Dietary supplementation with folate for 8 week (groupercentage of damaged vessels compared to a homocystine diet for 10 week (group H) but the percenin controls (group C) 

Authors’ Conclusions It is likely that folic acid supplementation may reduce cerebrovascular damage induced in hyperhomocyste

cellular oxidative metabolism. 

Quality A Limitations / Comments Rats in folate diet group were fed a diet with Hcy for 2 weeks before changed to folate-supplmented diet. T

were fed a diet without folate or Hcy for 2 weeks and then continued for another 8 weeks. For the purpcomparison is not appropriate. 

All rats had induced hyperhomocystinemia before the dietary allocation. 
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Rejected articles that used immature animal models Author, Year Robertson, 1968 

Central hypothesis/Stated Purposes of Study 

To investigate the ultrastructural features of early brain stem lesions in thiamine-deficient rats 

Hypothesis diagram Experimental diets or reagents 

Synthetic diet devoid of thiamine fed ad lib 

Control diets or reagents Above diet with daily subcutaneous injection of thiamine HCL 4μg/10 gm body weight Study characteristics Country: Canada 

Funding source: Medical Research Council of Canada 

Gap in Knowledge Known: 

Unknown: 

Experimental model Immature female hooded rats (Quebec Breeding Farms), weighing 50-65 gm at the outset Study design Final sample size Experimental 114; Isocaloric Controls 38; Equal-Weight Controls 20; Treatment Controls (thiamine deficie

injection for 4 days) 11 

Duration Animals were killed at daily intervals between days 27 & 41 by intracardiac perfusion of 3% glutaraldehydMeasurements / Endpoints / Outcomes of interest 

Behavior; brain lesions 

Other outcomes reported Results Thiamine deficient rats appeared well & continued to grow until about the 12th day, after which there was 

gradual loss of weight of about 1.5 gm/day. Neurologic signs first appeared between days 28 & 35; abequilibrium were followed in 2 or 3 days by loss of the ability to right themselves when rolled over, and stimulated to walk. Death followed in 1-3 days unless the animals had been perfused earlier. The continjections of thiamine displayed no neurologic signs, & apart from weight changes, appeared normal. 

Of 68 thiamine-deficient rats perfused on Day 27 and subsequent days of the experiment, 37 exhibited ne

these had lesions. In none of the 31 animals killed before neurologic signs appeared were histologic c

By light microscopy, minimal changes were seen in 6 rats, from days 28-33; they consisted of reticulated 

frequent focal swelling s of myelin sheaths and some axon irregularities. In 20 rats (Days 33-36) there 

hemorrhages & marked edema. Six animals (Days 38-41) exhibited varying degrees of frank necrosis

By electron microscopy, early lesions consisted of swelling of perivascular glial processes, with watery cy

glial processes & cell bodies away from vessel walls became swollen; fluid accumulation in occasiona

to separation of lamellae and distention of the sheaths. Later, there was patchy loss of perivascular glifoot processes contained small membrane bound vacuoles. Cytoplasm became swollen, cell membranorganelles underwent disintegration and the extracellular space became markedly enlarged. 

None of the control rats demonstrated lesions in the brain stem by electron microscopy. 

Authors’ Conclusions Not explicitly stated. Quality A Limitations / Comments 
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Author, Year Collins, 1970 

Central hypothesis/Stated Purposes of Study 

To evaluate the cerebellum in experimental animals rendered thiamine-deficient. 

Hypothesis diagram TD Æ glycogen accumulation within glial cells in the cerebellar molecular layer Æ neuronal damage or Experimental diets or reagents 

Complete diet containing 0.25 mg of thiamine per kg of diet. In order to avoid death from the acute effe

the animals were supplemented with intraperitoneal injections of thiamine hydrochloride containing Purina Rat Chow containing the same amount of thiamine. 

Control diets or reagents Pair-fed control: Purina Rat Chow was fed in daily amounts so as to reproduce the weight curve of the 

Normal control: synthetic diet containing 1.0 g of thiamine per kg of diet replaced the Purina Rat Chow 

Study characteristics Country: US 

Funding source: National Institute of Neurological Diseases and Stroke 

Gap in Knowledge Known: 

Unknown: The relationship between thiamine deficiency and cerebellar degeneration 

Experimental model Sprague-Dawley albino rats of both sexes weighing 100-120 g Study design Paralleled experiment-controlled trial Final sample size 7 animals (In total? Or in experimental group?) Duration 30 weeks Measurements / Endpoints / Outcomes of interest 

Clinical signs Histological findings: the sections of the cerebellar vermis were studied by phase microscopy, and thin 

staining with lead hydroxide, were studies by electron microscopy. 

Other outcomes reported Results Of the 7 animals studied, all showed ataxia at some time during the course of the experiment and were 

sacrifice. 

Cytoplasmic osmiophilic granules accumulation were found in glial cells in the molecular layer of the ce

the granular layer; authors stated that this granular material is consistent with glycogen granules bastaining characteristics. 

Dendritic spines in contact with and surrounded by glycogen-filled glial processes showed signs of deg

identifiable subcellular structures was markedly reduced). 

Authors’ Conclusions In thiamine deficient albino rats, marked glycogen accumulation was found within cerebellar glial cells a

process is associated with neuronal degeneration. 

Quality B Limitations / Comments 
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Author, Year Nakagawasai, 2000 Central hypothesis/Stated 

Purposes of the study 

To further clarify the correlation between changes in the level of SST in the brain, particularly in the hippoc

during TD 

Hypothesis diagram Thiamin deficiency Æ ↓ SST level in hippocampus Æ ↓ performance of passive-avoidance learning Experimental diets or 

reagents 

TD group: completely thiamine-deficient diet (CLEA Japan Inc., Tokyo, Japan) consisted of a basic ratio o

18% protein, and 8% lipid; it was supplemented with various vitamins, except for thiamine, and mineral

Single treatment with thiamin HCl: TD rats were given a single thiamine HCl [0.5 mg/rat, subcutaneous (s

or 21st day 

Control diets or reagents Pair-feeding control: the animals were given the same amounts of food as the TD group, however, the foo

thiamine HCl/100 g of diet (CLEA Japan Inc., Tokyo, Japan). 

Normal control group: the animals were allowed to freely take a complete normal diet containing thiamine. 

Study characteristics Country: Japan 

Funding source: No data 

Gap in Knowledge Known: Somatostatin (SST), a neuromodulator in the central nervous system, is rick in the cerebral cortex 

are integrative regions of cognitive function. Intracerebrally administered SST improves impairement of 

cysteamine-treated, scopolamine-treated, and nucleus basalis magnocellularis-lesioned rats in the pastest. It has been demonstrated that brain SST is one of the most severely affected systems in patients 

Unknown: Brain SST may be suggested to play a facilitatory role in cognitive function 

Experimental model Male Wistar rats, weighting 75-85 g at the beginning of the experiment Study design Paralleled experiment-controlled trial Final sample size N=8 per group Duration 25 days Measurements / Endpoints 

/ Outcomes of interest 

Step-through passive-avoidance task: the latency time of the retention trial was measured on the 14th and 

TD diet. 

Percentage of animals displaying impairment avoidance learning (entering in the dark compartment within 

was also recorded. 

Other outcomes reported SST content in the brain Results The latency time was not significantly changed on the 14th day as compared TD rats with the pair-fed rats

the latency time of the retention trial in the TD rats was significantly decreased as compared to the pair

The % of avoidance learning impairment of the TD significantly increased on the 25th day (p<0.05). 

The single thiamine HCL on the 14th day reversed the latency time of the retention trial to the control level 

However, when the thiamine HCl treatment was given on the 21st day, no reversal effect was observed 

the 25th day. 

Authors’ Conclusions The present study showed that the amnesia as determined by passive-avoidance task was gradually indu

start of TD feeding. Furthermore, the present data shows that this impairment of avoidance learning wa

an almost normal range merely by a single injection of thiamine HCl (0.5 mg/rat, s.c.) at a relatively ear

it remained reversed even with the continuation of the TD treatment until the 25th day. 

Quality A Limitations / Comments 
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Author, Year Stewart et al, 1975 

Stated Purpose of the Study 

To study the behavioral effects of pyridoxine deficiency in postweanling rats 

Hypothesis diagram Experimental diets or reagents 

Pyridoxine deficient diet 

Control diets or reagents 1. Pyridoxine deficient diet supplemented with 30 mg of Pyridoxine HCL/Kg of diet (ad lib) 

2. Pyridoxine deficient diet supplemented with 30 mg of Pyridoxine HCL/Kg of diet (pair-fed) 

Study characteristics Country: US 

Funding source: No data 

Gap in Knowledge Known: 

Unknown: 

Experimental model Male rats of the Charles River CD strain, 3 wk old and 7 wk old Study design See original paper for details regarding the 7 separate experiments. 

 The essential features of the apparatus used in the experiment included a start box, separated from the ru

guillotine door, and a safety box with no grids on the floor at the end of the runway. The entrance to the through a guillotine door. Shock could be delivered to the floor of the start box and runway but not to thboth the doors were raised that activated a light and buzzer that served as a conditional stimulus. The cremained on between the raising of the doors and the onset of the unconditional stimulus which was astimuli remained on until the rat escaped from the runway to the goal box at which time the stimuli were 

Final sample size See table 1 in original paper Duration 3-10 weeks, depending on the experiment Measurements / Endpoints / Outcomes of interest 

Avoidance response behavior Motor function (running time) Shock escape task Passive avoidance tack 

Other outcomes reported Results 1. The acquisition of avoidance response over 6 days showed their means (ANOVA) to differ signific

tests showed that the pyridoxine deficient group differ significantly from the two control groups, w

significantly from each other. 

2. Dietary deficiency had no effect on avoidance behavior in the developing animal until it had been 

weeks. 

3. It took the control rats 15 trials before reaching the criterion of 9 avoidance responses over 10 co

27.4 trials in the pyridoxine deficient rats (P<0.01) to reach the same criterion. 

4. Deficient animals were slower to start running in response to the electric shock throughout the tes

of animals showed improvement in their start times over the 30 trials of testing. 

5. Using running time as the measure, ANOVA showed that there was a main effect due to diet (P<0

(P<0.01) and an interaction between trials and diet (P<0.05). This interaction was due to the run t

being faster than controls for the first block of 5 trials and slower than controls for the remaining b

6. Animals were fed deficient or control diets from weaning until the end of week 8 when they were i

intraperiotneally with pyridoxine 50 mg/Kg and then tested on the shock avoidance responses. Thavoidance response in the deficient group was smaller than the control (P<0.01) at 3 days post in

is not significantly different at 7 days. 

7. Deficiency was induced in young animals starting at 7 weeks of age, i.e. at 4 weeks beyond the w
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deficient diet was continued for 7 weeks in one study, and for 10 weeks in another study. There wdifference in avoidance response between the two groups in both studies. 

8. Animals in another study were first trained to traverse up the runway for water reward and then pu

for making this response. ANOVA showed that the deficient animals had significantly faster runnigroups showed a significant reduction in running time over the 3 days (P<0.01). 

Authors’ Conclusions Avoidance behavior in rats is affected by pyridoxine deficiency. 

Five weeks of pyridoxine deficiency was sufficient to produce a deficit in active avoidance learning in the p

whereas up to 10 weeks of deficient diet ingestion produced no effect on young adult animals. 

Mild motor impairment was produced in the young pyridoxne-deficient rats but the avoidance learning defic

away on this basis, because a deficit in passive avoidance was also produced by the deficiency. 

Reversal of the deficiency by pyridoxine injection restored the active avoidance learning to normal within 1 

Quality A Limitations / Comments 
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Author, Year Guilarte, 1991 Central hypothesis/Stated 

Purposes of the study 

To quantitatively measure the effects of marginal vitamin B-6 nutrition during gestation, lactation, and post

locomotor activity of the developing rat. 

Hypothesis diagram Experimental diets or 

reagents 

Vitamin B6 deficient diet: 0.7 mg/kg pyridoxine HCl 

Control diets or reagents Vitamin B6 sufficient diet: 7.0 mg/kg pyridoxine HCl Study characteristics Country: US 

Funding source: No data 

Gap in Knowledge Known: B-6 deficiency during gestation and lactation results in abnormal CNS development in neonatal an

Unknown: Motor abnormalities, one of the most commonly described consequences of neonatal vitamin B

been systematically studied. 

Experimental model Male pup Long-Evans rats at 14, 28, and 56 days of age Study design After 2-3 weeks on the specified diet, female rats were mated with male rats. Within 24 hours of birth, offs

litter size culled to 8. Dams and offspring were maintained on their respective diet throughout the study

Final sample size N=6 per group Duration 56 days Measurements / Endpoints 

/ Outcomes of interest 

Locomotor activity measurements: Behavioral data collection was automated using a Digiscan Animal Act

Model #RXYZCM) coupled to a Digiscan Analyzer (Omnitech Model DCM-8). 1 male pup per litter was 

behavioral study in the computerized Digiscan system. Measurements on the same rat were obtained aage. 

Other outcomes reported Results The analysis of variance with repeated measures revealed that there were no significant dietary treatment 

locomotor activity variables measured. 

Further analysis of these overall interactions indicated that animals from the vitamin B6 restricted diet grou

of hypoactivity at 14 days of age followed by hyperactivity postweaning. This effect is demonstrated for horizontal activity, total distance, and number of vertical movements. Data for other behavioral measurpattern of locomotor behavior. 

Authors’ Conclusions The data clearly show 2 patterns of spontaneous locomotor behavior in the vitamin B6 restricted developin

life, vitamin B6 restriction produces a generalized hypoactivity in essentially all measures of locomotor 

finding in the present study is that in the postweaning period, at 28, 56, and 196 days of age, the vitam

became hyperactive in many of the indices of horizontal, rearing, and stereotypic behavior. The degree more apparent as the animals aged with many more indices of locomotor behavior demonstrating hype

Quality B Limitations / Comments No proxy measure for how “deficient” of those vitamin B6 restricted rats. Perhaps there is no significant dif

between the 2 groups. 

Postweaning rats were used. 
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B Vitamin Evidence Table – Animal / In Vitro Studies 

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Author, Year Ezer, 1976 

Central hypothesis/Stated Purposes of the study 

Vitamin B12 can promote the synthesis of RNA and of protein plays an important role in brain function, p

memory 

Hypothesis diagram Vitamin B12 Æ promote the synthesis of RNA and of protein Æ improve learning and memory Experimental diets or reagents 

Animals were fed on a standard diet and vitamin B12 was administered intraperitoneally at doses of 4x1

Control diets or reagents Animals were fed on a standard diet and vitamin physiologic saline or water containing tween 80 was ad

intraperitoneally 

Study characteristics Country: Hungary 

Funding source: No data 

Gap in Knowledge Known: The experimental methods elaborated for the laboratory investigation of the learning process on 

divided into 2 groups, either being based on the consolidation of Pawlov’s conditioned reflex, or applyconditioning. 

Unknown: The effect of vincristine and vitamin B12 on brain function assessed by a new simple method 

dose not require expensive instruments. 

Experimental model Female Wistar rats weighing 100-120 g. For those animals were selected (or learning-dull rats), which w

tape within 60 s during 3 selections (on 3 successive days). 

Study design Parallel experiment-controlled study Final sample size Control 96 

Vitamin B12 4x1 μg/kg:36 4x10 μg/kg:36 4x100 μg/kg:84 

Duration N/A (intraperitoneally) Measurements / Endpoints / Outcomes of interest 

Problem-solving ability: the problem-solving times were measured on 4 successive days, with posttrial tr

solving times are classified as follows: I (excellent) tearing off the tape in 1-20 s. II (good) tearing off t

(poor) tearing off the tape in 41-59s. IV (without success) failure to tear off the tape in 60s. 

P.S. index = (sum of problem solving I x 100)/sum of problem solving IV 

Other outcomes reported Results There was a dose-dependent effect of vitamin 12 on problem-solving ability in learning-dull rats. The res

and 3-4 trial blocks. The change of P.S. index values (except 1 μg/kg vitamin B12) is significant largeThe problem-solving times were significantly shorter in rats received higher dose of vitamin B12. 

Compared to the control animals, the distribution of P.S.T 1-4 trial block in rats received 4x100 μg/kg vita

toward shorter time categories (p<0.01). 

Authors’ Conclusions There is a stimulatory effect of vitamin B12 on problem-solving ability of the learning-dull rats and the effQuality B Limitations / Comments The statistical methods were not reported. Not sure why the comparison arms are not balanced. 

Vitamin B12 was administered intraperitoneally 
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Author, Year Sasaki et al, 1992; Sasaki et al, 1993 

Central hypothesis Acetylcholine contributes to learning and nicotine may improve learning in an acetylcholine deficient rat (d

in this table). The following data pertains to the effect of vitamin B12 on cognition in rats fed with a chol

Hypothesis diagram Experimental diets or reagents 

1. choline enriched diet (4 mg/g) 2. choline deficient diet (0 mg/g) 3. choline deficient diet supplemented with vitamin B12 (10 mg/Kg) 

Basal Diet Basal diet: standard rat chow containing 1.6 mg/g of choline chloride Study characteristics Country: Japan 

Funding source: SRF Grant for Biomedical Research 

Gap in Knowledge Known: 

Unknown: 

Experimental model 4 wk old male Wistar rats fed above diets Study design On diet for 10 weeks, then tested for passive avoidance learning. Step-through procedure: an apparatus c

compartments (one illuminated, one dark) separated by a door; an animal was placed into the illuminatdoor, could enter the dark side which has a grid floor; once all 4 paws are on the grid, an electric shock response latency in entering the dark compartment was measured. This learning was repeated on the 

Final sample size 10 in each group Duration 10 weeks Measurements / Endpoints / Outcomes of interest 

Latency time in Passive avoidance learning 

Other outcomes reported Whole brain choline and acetylcholine Results Latency time in choline-deficient supplemented with vitamin B12 rats was significantly longer than that of t

on the fourth day (P<0.05). 

Vitamin B12 increased tissue weight of the brain and content of acetylcholine in rats fed a choline-deficien

Authors’ Conclusions Vitamin B12 facilitated acetylcholine synthesis or release in the brain and improved the cognitive disturbanQuality B Limitations / Comments The improvement of cognitive disturbance may be due to intense input of shock stimuli. The study is not a

learning improvement from increased shock sensitivity in the step-through procedure. 

Not preferred comparisons. For our purpose of this review, the best comparisons in this coline deficient die

vs. choline deficient diet. 
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Author, Year Gospe et al., 1995 

Central hypothesis/Stated Purposes of the study 

The 1st experiment describes the effect of folate deficiency on the histopathology of brain and skeletal mus

The 2nd experiment compares the growth, food spilling behavior and the concentrations of total folate, cys

serum, and of neurotransmitters in the hypothalamus and caudate nucleus from folate-deficient and co

The 3rd experiment compares the growth, food spilling behavior and the concentrations of folate, SAM and 

(SAH) in whole brain and hematologic characteristics of folate-deficient and control mice 

Hypothesis diagram Experimental diets or reagents 

Amino acid based diet supplemented with 0 μmol folic acid for 38 days 

Control diets or reagents Amino acid based diet supplemented with 11.3 μmol folic acid per kg diet for 38 days Study characteristics Country: US 

Funding source: USPHS, USDA & California Experiment Station 

Gap in Knowledge Known: 

Unknown: 

Experimental model Weanling Swiss Webster female mice Study design 2 groups of mice of equal mean body weights and randomly assigned to the two diets. Measurement of bo

food given, spilled by the mice and food left in the feed cup were almost all obtained daily. At the end o

mice were killed by overdosing with diethyl ether and bled by cardiac puncture. 

Experiment 1, brains were removed and fixed in formalin for pathologic evaluation. Experiment 2, brains were removed, frozen in liquid nitrogen and weighed, caudate nuclei and hypothalam

frozen coronal section. Samples were analyzed for neurotransmitters and their metabolites. 

Experiment 3, whole brains were frozen and analyzed for total-folate, S-adenosylhomocysteine and S-ade

Final sample size Exp 1: 2 from folate-deficient group and 1 from the control group (not clearly reported) 

Exp 2: 5 in each group (only 4 of each were analyzed, data for one deficient and one control mouse were 

spilled very little food) 

Exp 3: 7 in each group 

Duration Exp 1: 38 days 

Exp 2: 37 days Exp 3: 39 days 

Measurements / Endpoints / Outcomes of interest 

Histological findings Neurotransmitters in the hypothalamus and caudate nucleus from folate-deficient and control mice 

Other outcomes reported Weight loss, food spilling behavior, and the concentrations of total folate, cysteine and homocysteine in seResults 1. After approximately 3.5 wk on the folic-acid deficient diet, growth rate declined and these mice ev

2. In Exp 2, at the end of the 37 day feeding period, folate-deficient animals weighed ~70% of the c

was consistent among the 3 studies. 

3. In Exp 2, the cumulative food spilled over the 37 day period in the folate-deficient group was 166 

control (p=0.0015). 

4. In Exp 2, the folate deficient group consumed 219 ± 21 g while the control consumed 174 ± 4 g (

folate deficient animals spilled more food, and gained less weight, they actually consumed more the experiment. Similar observations were recorded in Exp 3. 

5. Serum folate in the animals fed folic acid deficient diet were reduced to <5% of the control (p=0.6. Brain and spinal cord showed no apparent pathologic changes in folate-deficient animals. 7. Gastrocnemius and soleus muscles from folate deficient mice showed a reduction in the number 
Appendix C. Evidence Tables 

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to control mice. 

8. Differences in hypothalamic concentrations of norepinephrine, dopamine, or their metabolites be

mice were not significant. Caudate dopamine levels were reduced by 36% (p=0.04), 3,4-dihydrox(DOPAC) by 48% (p=0.03), and homovanillic acid (HVA) by 43% (p=0.047) in folate-deficient micacetic acid (5-HIAA)/ serotonin (5HT) ratio was lower in folate deficient mice compared to control 

9. Animals fed folic acid deficient diet had significantly lower whole brain folate and SAM; whole bra

(p=0.01) and SAM was 40% lower (p=0.035). Whole brain (s-adenosyl homocysteine) SAH was (s-adenosyl methionine) /SAH ratio was 43% lower (p=0.047) 

Authors’ Conclusions The combination of weight loss and augmented food consumption suggests that folate depletion may redu

animals utilize dietary nutrients to meet physiological functions, suggesting that an alteration in hypotha

neuroendocrine function may underlie this effect of folate depletion. In addition, these changes may be 

induced reduction in nutrient absorption. 

These studies were designed to characterize the food spilling behavior of folate deficient mice and to dete

neurochemical basis. Precautions were taken to minimize the effects of diurnal variation on the results 

included housing the mice in a room with a 12 h light dark cycle, feeding and weighing the mice at the alternately killing control and deficient mice within a 2 h window at the end of each experiment. 

Quality B Limitations / Comments The feeding patterns during the dark cycle were not monitored. Exp 3 has no outcome of interests to this r
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B Vitamin Evidence Tables – Human Studies 
Appendix C. Evidence Tables 

B Vitamin Evidence Tables - Human studies 

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Intervention

Author, Year: Abyad, 2002 Ref ID: 53 Vitamins: B12 

Objective: To determine whether dementia is associated with low serum B12 levels and whether treatment of demented patients w

B12 have any impact on memory 

Study characteristics Population Controls Inclusion criteria Exclusion criteria D

Study design Prospective 

longitudinal 

Age: 82 N/A AD: 

Country: Lebanon %Male: 36 N/A PD: Setting: Nursing 

home and outpatient clinic 

Race: VascDz:

Funding: ND Other: 

Nursing home residents and outpatients with Dx of dementia and low serum B12 level (<300 pg/mL) 

ND 

Other: Acc

crite

Comments: No definition for dementia type is provided Intervention(s): Control: N/A Total Intervention 1 InterventB12: 1000 μg iv daily for 1 week; then weekly for 1 month; then monthly thereafter 

N enrolled: 62 62 N analyzed: 56 56 Drop-outs (%): 6 (11) 8 (14) 

Follow-up duration: 12 months Reasons for drop out: death: 2; ND: 4 Comments: Primary outcome(s): Folestein MMSE (23-27: mildly impaired; 19-23: moderately impaired; ≤19: severely impaired) Secondary outcome(s): Adverse events: ND Limitations: No normal (without dementia) control group; small sample size; power calculation not reported Quality (A/B/C): C Applicability (1/2/3): 1 
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Outcome(s): Results (Text) (or Definition) MMSE At 3 months to 12 months of follow-up, 40 /56 subjects improved in their mental status score. Six subjects gain

respectively, and essentially normalized their scores. Three patients maintained their score after 1 year of follow

feature that predicted amelioration in MMSE following treatment was a short duration of pre-treatment mental 

All Subjects Outcome MMSE (0-100) 

 N B12 1000 μg iv N (Intervention) (Dose) N (Intervention) 

Baseline value (SE/SD) 56 14.5 7.7 Final value (SE/SD) 56 15 9.9 Difference (SE/SD/95% CI) +0.5 2.12 P Difference ND Net Difference (SE/SD/95% CI) P Net difference Short Symptom Duration*Outcome MMSE (0-100) 

 N B12 1000 μg iv N (Intervention) (Dose) N (Intervention) 

Baseline value (SE/SD) 22 19 5 Final value (SE/SD) 22 25 4 Difference (SE/SD/95% CI) +6 ND P Difference 0.0065 Net Difference (SE/SD/95% CI) P Net difference * MMSE score of patients with short (<12 months) pre-treatment symptom duration; adjusting for age, level of education, or serum B1measures analysis of covariance did not alter the significance of this relationship Long Symptom Duration**Outcome* MMSE (0-100) 

 N B12 1000 μg iv N (Intervention) (Dose) N (Intervention) 

Baseline value (SE/SD) 34 18 4 Final value (SE/SD) 34 22 2 Difference (SE/SD/95% CI) +4 ND P Difference 0.25 Net Difference (SE/SD/95% CI) P Net difference ** MMSE score of patients with long (>12 months) pre-treatment symptom duration 
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Intervention

Author, Year: Aisen, 2003 Ref ID: 75 Vitamins: 

Objective: Effect of multi-B vitamin on Hcy and cognitive function 

Study characteristics Population Controls Inclusion 

criteria 

Exclusion criteria 

Study design Prospective 

longitudinal cohort 

Age: 70.8+/-

9.4 

Country: US %Male: 36% Setting: Clinics Race: Funding: Government AD 

duration: 

3.3+/-

2.5 yr 

Medically stable, probable AD 

Significant renal insufficiency (Cr>1.5 mg/dL), history of B12 or folate deficiency, use of vitamin supplement containing >400 μg folate, regular use of B12 injections, or medications known to influence homocysteine metabolism (eg, methotrexate, azathioprine, phenytoin) 

Comments: Open label Intervention(s): Control: Total Intervention 1 Intervent

N enrolled: 69 N analyzed: 63 

Folate 5 mg Vitamin B12 1 mg Vitamin B6 50 mg Drop-outs (%): 9% Follow-up duration: 8 wk Reasons for drop out: nd Comments: Compliance, by pill count exceeded 80% Primary outcome(s): Homocysteine level Secondary outcome(s): MMSE, Alzheimer Disease Assessment Scale cognitive subscale (ADAScog), Geriatric Depression ScalAdverse events: No serious adverse events and in no instance was the vitamin regimen discontinued as a result of adverse 

was an adverse symptom judged to be related to the study intervention. 

Limitations: Quality (A/B/C): C Applicability (1/2/3): 2 Outcome(s): Results (Text) (or Definition) 
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C-40 

Outcome MMSE (0-30) 

 N Multivitamin N (Intervention) (Dose) N (Intervention) (

Baseline value (SD) 63 19.2 7.0 Final value (SD) 63 19.3 7.7 Difference P Difference NS Net Difference P Net difference (RR/OR/HR) P (RR/OR/HR) Lack of association between multivitamin use and cognitive decline (unclear if MMSE or ADAScog) was not affected by controlling fo
Appendix C. Evidence Tables 

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C-41 

Intervention

Author, Year: Blass, 1988 Ref ID: 330 Vitamins: Thiamine 

Objective: Effect of high dose thiamine on cognitive function in patients with AD 

Study characteristics Population Controls Inclusion 

criteria 

Exclusion criteria Defin

Study design Randomized 

Xover 

Age: 72 AD: National Ins

CommunicaAlzheimer’s Disorders A“probable A

Country: US %Male: 36% PD: Setting: Specialty 

clinic 

Race: nd VascDz: nd 

Funding: NIH, private Other: 

Dementia clinic with diagnosis of AD 

Cerebrovascular disease; Hachinski score (for multi-infarct dementia) >4 

Other: 

Comments: Intervention(s): Control: Total Intervention 1 InterventThiamine HCl 1 g TID N enrolled: 16 

N analyzed: 11 

Niacinamide 250 mg TID 

Drop-outs (%): 31% 

Follow-up duration: 3 mo Reasons for drop out: 2 hospitalized; 3 required antidepressant Comments: Randomization performed by pharmacy Primary outcome(s): MMSE, Blessed Score, Haycox Score Secondary outcome(s): Adverse events: None Limitations: Small sample size, incomplete description of sample or outcomes Quality (A/B/C): C Applicability (1/2/3): 1 Outcome(s): Definition MMSE Mini-Mental State Examination, completed by nurse Blessed Score Behavioral rating, completed by nurse (Blessed et al. The association between quantitative measures of dement

cerebral gray matter of elderly subjects. Br J Psychiatry 1968; 114:797-811) 

Haycox Score Behavioral rating, competed by caretaker (Haycox et al. A simple, reliable clinical behavioral scale for assessin

Clin Psychiatry 1984;45:23-4) 
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C-42 

Outcome MMSE (score) 

 N Thaimine 3 g/day N Cont

Baseline value (SEM) 11 14.2 (1.4) 11 same Final value (SEM) 11 15.5 (1.5) 11 14.7 Difference (SEM) +1.35 (0.67) +0.54 P Difference 0.08 0.45 Net Difference (SEM) +0.72 (0.14) P Net difference <0.001 Outcome Blessed (score) 

 N Thaimine 3 g/day N Cont

Baseline value (SEM) 11 7.41 (0.81) 11 same Final value (SEM) 11 7.55 (1.00) 11 6.93 Difference (SEM) +0.14 (0.64) -0.48 P Difference 0.83 0.27 Net Difference (SEM) +0.62 (0.52) P Net difference 0.27 Outcome Haycox (score) 

 N Thaimine 3 g/day N Cont

Baseline value (SEM) 11 11.1 (1.2) 11 same Final value (SEM) 11 13.4 (1.8) 11 12.2 Difference (SEM) +2.29 (1.40) +1.10 P Difference 0.13 0.40 Net Difference (SEM) +1.21 (0.81) P Net difference 0.17 “Subjectively, no important clinical changes were observed in these moderately impaired patients during their 3 months of receiving thniacinamide placebo)” 
Appendix C. Evidence Tables 

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C-43 

Intervention

Author, Year: Carmel, 1995 Ref ID: 10010 Vitamins: 

Objective: Effects of cobalamin replacement on dementia patients 

Study characteristics Population Controls Inclusion criteria Exc

cr

Study design Cohort Age: 71 Country: USA %Male: 25 Setting: Outpatient facilities for dementia, 

affiliated w/university & VA medical center 

Race: ND 

Funding: Government Other: 

Dementia patients, low cobalamin levels < 190 ng/l 

ND 

Comments: Subjects grouped by DSM-III-R criteria into following categories: probable AD, possible AD, and other dementia; con

dementia; cobalamin assay with reference interval 90-1016 ng/l – established by 332 healthy volunteers 

Intervention(s): Control: Total Intervention 1 InterventCyanocobalamin 1000 μg IM per wk x 8 wk, then per mo for ≥4 mo 

N enrolled: 16* N analyzed: 14 Drop-outs (%): 

Follow-up duration: 1 follow-up after 6-8 months 

therapy 

Reasons for drop out: 

Comments: *34 AD pts with low cobalamin levels – unclear how many were actually enrolled. Stated 9 pts fully studied, 7 partially 

refused further tx, were on cobalamin prior to being studied, or did not comply with tx. CERAD battery pre-treatment fodementia in 13 pts & 3 nondementia pts 

Primary outcome(s): Neuropsychological outcomes via CERAD battery results including MMSE, 15-item naming tas

verbal memory task, visuoconstructive task

Secondary outcome(s): Adverse events: Limitations: Quality (A/B/C): C Applicability (1/2/3): 1 
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C-44 

Outcome(s): Results (Text) Neuropsychologic Report only overall improvement/worsening in cognitive testing (N=14) 

Improved or became normal – 1 (improvement in several CERAD tasks) No change – 12 Worse – 1 (functional progression of dementia, CERAD results did not change noticeably) 
Appendix C. Evidence Tables 

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C-45 

Intervention

Author, Year: Deijen, 1992 Ref ID: 10006 Vitamins: 

Objective: Effect of B6 supplementation on memory etc. 

Study characteristics Population Controls Inclusion criteria Exclusion criteria 

Study design RCT Age: 73 73 Country: Netherlands %Male: 100 100 Setting: Population Race: nd nd 

 PLP 31 29 

α-EAST 1.75 1.83 

Funding: nd 

 IQ 109 111 

Male, 70-79 yr, healthy, EtOH<4/day, IQ>80 

Drugs that affect B6 metabolism, drugs affecting reactivity, B6 supplement within 3 mo, auto-immdiseases, long-acting hypnotics or anti-depressanmo, drug or EtOH addiction, abnormal chemical/hematological profile, sensory or motor that may affect testing. 

Comments: Subjects paired by age, vitamin B6 status and IQ, then randomized. PLP: plasma pyridoxal-f’-phosphate; α EAST: erythrocyte enzyme aspartate aminotransferase activation 

Intervention(s): Control: Total Intervention 1 Intervent

N enrolled: 82 41 N analyzed: 76 38 

Vitamin B6 (pyridoxine HCl) 20 mg per day 

Placebo (identical capsules) 

Drop-outs (%): 7% 

Follow-up duration: 12 wk Reasons for drop out: 3: illness; 3 were matched subjects to the ill Comments: Complicated statistical analyses performed. Different for each outcome. Suggests that authors may have been fishing foPrimary outcome(s): Cognitive functioning Secondary outcome(s): Pupil size as measure of mental effort, B 6 status, mood Adverse events: nd Limitations: Non-standardized tests. Questionable statistics. Incompletely reported data. Quality (A/B/C): C Applicability (1/2/3): 2 Outcome(s): Results (Text) (or Definition) Associate Learning Task Test of short term verbal memory, remembering name-occupation pairs (9 pairs) Associate Recognition Task Test of long term verbal memory, same as Associate Learning Task with 1 hr delay (9 pairs) Long Term Memory Storage Difference (by subtraction) between Associate Learning and Recognition Tasks (what is forgotten) (9 Short Term Memory Task (Pupilometry) 

Pupil diameter measured during timed memory/visual recognition test. Measures “mental effort” as a 

pupil response, reaction times and number of correct responses. (41 trials) 

Speed of Processing Task (Pupilometry) 

Pupil diameter measured during timed task requiring choosing button on opposite corner of displayed “mental effort” as a combination of phasic pupil response, reaction times and number of correct respo
Appendix C. Evidence Tables 

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C-46 

Outcome Associate Recognition Task (0-9) Reported 

 N B6 20 mg N 

Baseline value (SD) 38 3.2 (2.3) 38 Final value (SD) 38 3.3 (2.3) 38 Difference P Difference NS Net Difference P Net difference Outcome Long Term Memory Storage (Forget Score) (0-9, low score better) Re

 N B6 20 mg N 

Baseline value (SD) 38 0.35 (1.4) 38 Final value (SD) 38 0 (1.4) 38 Difference P Difference P<0.03 Net Difference P Net difference Associate Learning Task: Multivariate one-way ANCOVA did not show a multivariate difference between groups. 

Mental Effort Tests: Number of correct responses and reaction times on speed of processing task and memory task were the same for 

responses were the same for both groups. 
Appendix C. Evidence Tables 

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C-47 

Intervention

Author, Year: Fahn, 1974 Ref ID: 938 Vitamins: 

Objective: Effect of pyridoxine on L-Dopa in patients with PD and severe “on-off” effects 

Study characteristics Population Controls Inclusion criteria Exc

cr

Study design Prospective 

longitudinal cohort (Xover) 

Age: 53 (40-64) 

Country: US %Male: 60% Setting: Clinic (admitted 

for study) 

Race: nd 

Funding: Government, 

Pharmaceutical 

Other: 1.5-3 y L-Dopa 

2 postthalamotomy 

Idiopathic PD, severe on-off effects such that they could no longer function normally. (Initial excellent response to L-Dopa, then choreic movements developed, then on-off: sudden loss of effectiveness with abrupt onset of akinesia followed by equally sudden return of effectiveness). Stabilized for at least 7 days on L-Dopa or Carbidopa/L-Dopa doses. 

(Amadiscon

Comments: Intervention(s): Control: Total Intervention 1 InterventPyridoxine 100 mg IM with L-Dopa (1 dose) 

L-Dopa alone N enrolled: 5 5 

Pyridoxine 100 mg IM with N analyzed: 5 5 Carbidopa/L-Dopa (1 dose) 

Carbidopa/L-Dopa alone 

Drop-outs (%): 

Follow-up duration: 1 dose each, separated by at least 7 days Reasons for drop out: Comments: Primary outcome(s): Plasma levels of Dopa, homovanillic acid (HVA), 3-O-methyldopa (OMD), Secondary outcome(s): Clinical state (not clearly defined) Adverse events: Limitations: Quality (A/B/C): Applicability (1/2/3): 3 Outcome(s): Results (Text) (or Definition) Clinical state No alteration in clinical state after a single dose of pyridoxine intramuscularly either while receinving L-Dopa aHVA, OMD No change in plasma levels after a single dose of pyridoxine intramuscularly (shown graphically from 9 am to ~Dopa Dopa consistently decreased slightly with pyridoxine compared to no pyridoxine (shown graphically from 9 am 

Effect not seen with combination Carbidopa/L-Dopa 
Appendix C. Evidence Tables 

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C-48 

Intervention

Author, Year: Fioravanti,1997 Ref ID: 10007 Vitamins: 

Objective: To evaluate the effect of folate supplementation on cognitive deficits fo aged patients in a controlled trial 

Study characteristics Population Controls Inclusion criteria Exclusion criteria 

Study design RCT Age: 80.25 

(5.78) 

80.21 

(5.45) 

Country: Italy %Male: 25% 8% Setting: Community 

and conducted by authors in an academic setting 

Race: ND ND 

Funding: nd Other: 

weight in Kg 

63.88 

(14.42) 

57.29 

(10.56) 

Patients recruited among the elderly (70-90 yr) living either at home or in a community and had folate below 3 ng/mL and diagnosed to have mild to moderate severity of cognitive decline as assessed by Global deterioration scale 

Patients with gastrointestinal, endocrine, CVD, or renal pathology, diagnosed with depression, with no cognitive decline (MMSE >24) or with a clear diagnosis of dementia (MMSE <16). And also those with regular intake of vitamins oof more than 55g of alcohol 

Comments: Intervention(s): Control: Total Intervention 1

Folate 

Intervent

Folic acid 15 mg/d po N enrolled: 30 16 

N analyzed: 30 16 

Placebo similar to the intervention 

Drop-outs (%): 0% 

Follow-up duration: 60days Reasons for drop out: Comments: No cognitive enhancer drugs or other treatments active on the CNS were allowed during the treatment period Primary outcome(s): Randt Memory Test: a multidimensional memory test consisting of 5 different tasks Secondary outcome(s): Adverse events: ND Limitations: Small sample and short duration of treatment Quality (A/B/C): B Applicability (1/2/3): 2 Outcome(s): Results (Text) (or Definition) Cognitive improvement 

Greater folate deficiency at the beginning of treatment was related to greater cognitive improvement after 2 mo

However there was a lack of correlation between severity of folate deficiency and severity of cognitive decline 
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C-49 

Blood folate level at baseline  N= Mean SD Folate treatment group 16 2.34 0.51 Placebo treatment group 14 2.21 0.68 Outcome Acquisition and recall (part of Randt Memory Test) nd on scale 

 N Folate po 15 mg N 

Baseline value (SE/SD) 16 55.31 12.06 14 Final value (SE/SD) 16 59.56 12.53 13 Difference (SE/SD/95% CI) P Difference NS Net Difference (SE/SD/95% CI) P Net difference <0.007 (RR/OR/HR) 95% CI P (RR/OR/HR) Outcome Delayed recall (part of Randt Memory Test) nd on sc

 N Folate po 15 mg N 

Baseline value (SE/SD) 16 56.06 11.16 14 Final value (SE/SD) 16 63.44 13.90 13 Difference (SE/SD/95% CI) P Difference NS Net Difference (SE/SD/95% CI) P Net difference <0.007 (RR/OR/HR) 95% CI P (RR/OR/HR) Outcome Memory index (part of Randt Memory Test) nd on sca

 N Folate po 15 mg N 

Baseline value (SE/SD) 16 49.25 12.26 14 57Final value (SE/SD) 16 56.06 13.90 13 56Difference (SE/SD/95% CI) NS P Difference Net Difference (SE/SD/95% CI) P Net difference <0.002 (RR/OR/HR) 95% CI P (RR/OR/HR) 
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Outcome Encoding (part of Randt Memory Test) nd on 

 N Folate po 15 mg N 

Baseline value (SE/SD) 15 4.33 2.11 14 Final value (SE/SD) 16 4.79 1.72 13 Difference (SE/SD/95% CI) NS P Difference Net Difference (SE/SD/95% CI) P Net difference <0.005 (RR/OR/HR) 95% CI P (RR/OR/HR) Outcome Cognitive efficiency (part of Randt Memory Test) nd on 

 N Folate po 15 mg N 

Baseline value (SE/SD) 16 3.28 1.77 14 Final value (SE/SD) 16 3.91 2.62 13 Difference (SE/SD/95% CI) P Difference NS Net Difference (SE/SD/95% CI) P Net difference NS (RR/OR/HR) 95% CI P (RR/OR/HR) Outcome Attention efficiency (part of Randt Memory Test) nd on 

 N Folate po 15 mg N 

Baseline value (SE/SD) 16 6.40 0.77 14 Final value (SE/SD) 16 7.52 1.48 13 Difference (SE/SD/95% CI) P Difference <0.05 Net Difference (SE/SD/95% CI) P Net difference NS (RR/OR/HR) 95% CI P (RR/OR/HR) 
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C-51 

Intervention

Author, Year: Hsu, 1973 Ref ID: 1401 Vitamins: 

Objective: Interaction of B6 and L-DOPA in PD 

Study characteristics Population Controls Inclusion criteria Exclusion c

Study design Prospective longitudinal 

cohort 

Age: 57-76 

Country: US %Male: nd Setting: Outpatient (in metabolic 

ward) 

Race: nd 

Funding: Private; Merck, Sharp 

and Dohme 

Other: 

Cases: PD, treated with L-Dopa 3-6 g/day during the previous 2 yr 

Cases: Cardiac, renal hepatic disease 

Comments: Trial also done in 4 healthy controls. Intervention(s): Control: Total Intervention 1 Intervent

N enrolled: 5 5 N analyzed: 5 5 

L-Dopa 2 g/day x 7 days, Pyridoxine 150 mg/day, days 8-9 

none 

Drop-outs (%): 

Follow-up duration: 2 days Reasons for drop out: Comments: Metabolic study Primary outcome(s): Urinary excretion of Dopa and Dopa metabolites (Dopa, Dopamine, dihydroxyphenylacetic acid [DOPA

[HVA]) 

Secondary outcome(s): Parkinsonian symptoms Adverse events: Limitations: Small sample size, short duration, clinical outcomes not measured in systematic fashion Quality (A/B/C): C Applicability (1/2/3): 3 
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C-52 

Outcome(s): Results (Text) (or Definition) 24 hr urinary excretion of Dopa and metabolites 

Simultaneous administration of pyridoxine and L-Dopa significantly decreased urinary excretion of Dopa and i

Dopa metabolites (though dopamine was not significantly increased in 24 hour urine). 

Parkinsonian symptoms 

Deterioration of symptoms in 2 of 5 patients, manifested by increased tremor, which persisted for 24 hr after di

pyridoxine. 

24 hour urine excretion 

 N DOPA mg Dopamine mg DOPAC m

Baseline value (SD) 5 51.5 4.3 150.3 50.0 57.0 26.0 Final value (SD) 5 35.5 3.1 174.1 51.8 95.3 25.2 Difference P Difference <0.02 <0.10 (NS) <0.02 
Appendix C. Evidence Tables 

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C-53 

Intervention

Author, Year: Hvas, 2004 Ref ID: 1414 Vitamins: B 12 

Objective: To assess the cognitive function and symptoms of depression in individuals with elevated plasma methyl malonic acid 

Study characteristics Population Controls Inclusion criteria Exclusion criteria D

Study design RCT Age: 75 74 AD: Country: Denmark %Male: 33% 35% PD: Setting: University Race: Nd nd VascDz:Funding: Private and 

meds Industry 

Other: CAMCOG

89 89 

Elevated plasma methyl malonic acid (P-MMA) 

nd 

Other: Co

Comments: The Cambridge Cognitive Examination (CAMCOG) assesses broad range of cognitive functions and contains 60 items 

mean score <90 is cognitively impaired 

Intervention(s): Control: Total Intervention 1 InterventCynacobalamin 1 mg IM N enrolled: 140 70 

N analyzed: 140 70 

Isotonic sodium chloride 1 ml 

Drop-outs (%): 0% 

Follow-up duration: 4 wk treatment and 3 mo followup Reasons for drop out: Comments: Primary outcome(s): The Cambridge Cognitive Examination (CAMCOG); Mini mental Status examination; 12 word leDescription of outcomes MMSE a score below 25 indicates cognitive impairment; 12 word learning test is sensitive for shoSecondary outcome(s): Plasma tHcy Adverse events: nd Limitations: Quality (A/B/C): A Applicability (1/2/3): 2 P-MMA and P-tHcy measurement methods available Outcome(s): Results (Text) (or Definition) 
Appendix C. Evidence Tables 

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C-54 

CAMCOG (0-100) 

 N B 12 1 mg N 1 mg Isotonic sodium chloride 

Baseline value (SE/SD) 70 89 : 70 89 Final value (SE/SD) 70 70 Difference (SD) +1.3 4.8 +1.9 4.3 P Difference 0.04 0.001 Net Difference (95% CI) -0.6 (-2.2, +0.9) P Net difference NS Outcome MMSE (0-100) 

 N B 12 1 mg N 1 mg Isotonic sodium chloride 

Baseline value (SE/SD) 70 26 70 27 Final value (SE/SD) 70 70 Difference (SD) +0.3 2.3 +0.2 1.7 P Difference NS NS Net Difference (95% CI) +0.1 -0.6; +0.8 P Net difference NS 12 word learning test, immediate 0-12 

 N B 12 1 mg N 1 mg Isotonic sodium chloride 

Baseline value (SE/SD) 70 5 70 5 Final value (SE/SD) 70 70 Difference (SD) +0.2 1.4 +0.4 1.7 P Difference NS 0.04 Net Difference (95% CI) -0.2 -0.7; +0.3 P Net difference NS 12 word learning test, 15 min 0-12 

 N B 12 1 mg N 1 mg Isotonic sodium chloride 

Baseline value (SE/SD) 70 2 70 2 Final value (SE/SD) 70 70 Difference (SD) +0.2 0.35 +0.7 1.7 P Difference NS 0.001 Net Difference (95% CI) -0.5 -1.1; -0.02 P Net difference 0.04 
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C-55 

Intervention

Author, Year: Ikeda, 1992 Ref ID: 1431 Vitamins: 

Objective: IV B12 for AD 

Study characteristics Population Controls Inclusion criteria Exclusion criteria 

Study design Prospective 

longitudinal cohort 

Age: 71+/-13 AD: 

Country: Japan %Male: 40% PD: Setting: Unclear Race: Japanese VascFunding: nd Other: 

Alzheimer-type senile dementia or AD 

History of serious diseases 

Othe

Comments: Intervention(s): Control: Total Intervention 1 Intervent

N enrolled: 10 N analyzed: 10 

IV mecobalamin 500 μg 3x/week x 8 wk 

None 

Drop-outs (%): 

Follow-up duration: 12 wk Reasons for drop out: Comments: Primary outcome(s): MMSE, Mattis’ Dementia Rating Scale Secondary outcome(s): Other scales: Modified Gottfries-Brane-Steen scale (M-GBS), Hasegawa’s Dementia Rating Scale (HDS

Scale, Subjective symptoms, Neurological symptoms, Activities of daily living, Caregiver evaluation, Ov

Adverse events: No side effects were detected in the laboratory tests nor were there any patient complaints. Limitations: Quality (A/B/C): C Applicability (1/2/3): 1 
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MMSE (0-30) Data Presented Graphically Only 

 N IV Mecobalamin 500 μg 3x/wk N N 

Baseline value (SD, implied) 10 20 7 Final value, 8 wk (SD, implied) 10 21 8 Post-Tx, 12 wk (SD, implied) 10 20 7 Difference (SE/SD/95% CI) P Difference NS (all time points) Mattis’ DMR (Japanese Version), Total (0-150) Data Presented Graphically Only 

 N IV Mecobalamin 500 μg 3x/wk N 

Baseline value (SD, implied) 10 112 25 Final value, 8 wk (SD, implied) 10 115 25 Post-Tx, 12 wk (SD, implied) 10 115 27 Difference (SE/SD/95% CI) P Difference <0.05 (all time points) Outcome(s): Results (Text) (or Definition) DMR, sub-scales Significant increase in Memory (P<0.05) 

No significant change in Attention, Intention & Perseveration, Construction, Conceptualiz

Modified GBS Significant improvements in Intellectual functions, Emotional functions, and Total (P<0.0

No significant change in Initiatives, Different symptoms common in dementia, or Motor f

Hasegawa’s Dementia Rating Scale (HDS) Significant improvement in scale (P<0.05) Subjective symptoms (insomnia) Before treatment 6/10 complained of insomnia; all 6 had improvement in sleep. Neurological symptoms 6/10 had symptoms before treatment. Improvement was seen in 2 who had sensory disturb

The remaining 4 had no change. 

Activities of Daily Living No significant changes were apparent with treatment. Caregiver evaluation (list of items) 3/10 improved, 5/10 slightly improved, 2/10 no change. None deteriorated. 

Items that improved considerably after mecobalamin administration were talkativeness an

Overall evaluation (not defined) 3/10 moderately improved, 6/10 slightly improved, 1/10 no change. 
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Intervention

Author, Year: Ito, 2001 Ref ID: 1451 Vitamins: 

Objective: B12 in Alzheimer-type dementia 

Study characteristics Population Controls Inclusion criteria Exclusion criteria 

Study design Longitudinal, non-randomized 

one-way partial crossover 

Age: 78.3 AD: 

Country: Japan %Male: 43% PD: Setting: nd Race: Japanese VascDFunding: nd Other: 

Alzheimer-type dementia 

Physical problems, medication 

Other: 

Comments: Unclear how those getting Vit B12 were chosen. 

All received bright light x 4 wk, then half given B12 in addition to bright light. Analysis done on half at 4 wk and on other half with vit B12 + 8 wk bright light 

Intervention(s): Control: Total Intervention 1 Intervent

N enrolled: 28 14 N analyzed: 28 14 

Bright light therapy x 8 wk + B12 1.5 mg/d (wk 5-6), B12 3.0 mg/d (wk 7-8) 

Bright light therapy x 8 wk 

Drop-outs (%): 

Follow-up duration: 4 wk on B12 Reasons for drop out: No data reported on patients who were not tComments: Primary outcome(s): Clinical Dementia Rating (Hughes 1982; questionable 0.5 points, mild 1, moderate 2, severe 3), MMSE Secondary outcome(s): Sleep Adverse events: nd Limitations: Analyzed as an uncontrolled cohort Quality (A/B/C): C Applicability (1/2/3): 2 
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MMSE (0-30) 

 N B12: All 1.5-3 mg/d N B12: QMD** 1.5-3 mg/d N B12: MSD** 1.5-3 

Baseline value (SD) nd Final value (SD) 14 10.4 7.6 Difference P Difference of Final values NS NS NS Baseline value (SD) nd Final value (SD) 6 17.7 5.1 Difference P Difference of Final values NS Baseline value (SD) nd Final value (SD) 8 4.9 2.9 Difference P Difference of Final values NS * Week 4 of study, when B12 was started ** Subsets: QMD: questionable (0.5 points) or mild (1 point) dementia; MSD: moderate (2 points) or severe (3 points) dementia. Outcome(s): Results (Text) (or Definition) Clinical Dementia rating 

No change with treatment 

Sleep Significantly less sleep during the day. No difference in sleep at night. 
Appendix C. Evidence Tables 

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C-59 

Intervention

Author, Year: Kwok, 1998 Ref ID: 354 Vitamins: 

Objective: B12 supplementation of deficient patients on cognitive function 

Study characteristics Population Controls Inclusion criteria Exclusion criteria 

Study design RCT Age: 76.6+/-

6.8 

77.4+/-

6.4 

Country: Hong 

Kong 

%Male: 4% 0% 

Setting: Outpatient Race: nd nd Funding: nd Baseline 

B12 (nmol/L): 

87.3+/-

24.0 

77.9+/-

27.8 

>60 yr and Serum B12 <120 pmol/L, vegetarians living at home or residence (majority of recruits) or nonvegetarians found to be B12 deficient as outpatient (minority of recruits). 

Could not cooperate with neuropsychological tests because of severe confusion or communication problems; Hgb <9.0 g/dL, unstable medical condition, signs of combined degeneration of spinal cord 

Comments: randomization by HK ID card number (odd v even) Intervention(s): Control: Total Intervention 1 Intervent

N enrolled: nd nd N analyzed: 50 23 

Cobalamin 1 mg IM x 3 in wk 1, then 1 mg qWk x 3, then 1 mg qMo 

No intervention 

Drop-outs (%): 

Follow-up duration: 3-6 months: B12 17.3+/-5.5 wk 

 Control 16.1+/-3.2 wk 

Reasons for drop out: 

Comments: Psychologists were blinded Primary outcome(s): Neuropsychological tests (including motor tests, not included here) Secondary outcome(s): Adverse events: nd Limitations: Insufficient data about tests. Mix of 2 different populations. Quality (A/B/C): C Applicability (1/2/3): 2 
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Outcome(s): Definition MMSE Digit span nd WAIS-R Defined as “similarities and block design subtests, and logical memory and visual reproduction subtests”. 

In Results, listed as Visual and Verbal memory, Verbal and Performance IQ. 

WAIS-R, Wechsler Adult Intelligence Scale-Revised 
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Outcome MMSE (0-30) 

 N B12 N 

Baseline value (SD) 27 22.2 (4.7) 23 Final value (SD) 27 22.3 (4.2) 23 Difference P Difference NS NS Net Difference P Net difference NS Outcome Visual Memory (nd) 

 N B12 N 

Baseline value (SD) 27 12.7 9.0 23 Final value (SD) 27 9.7 9.4 23 Difference P Difference NS NS Net Difference P Net difference NS Outcome Verbal Memory (nd) 

 N B12 N 

Baseline value (SD) 27 7.8 6.1 23 Final value (SD) 27 6.7 5.9 23 Difference P Difference NS <0.Net Difference P Net difference NS Outcome Digit Span (nd) 

 N B12 N 

Baseline value (SD) 27 10.4 3.8 23 Final value (SD) 27 10.7 3.6 23 Difference P Difference NS NS Net Difference P Net difference NS 
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Outcome Verbal IQ (nd) 

 N B12 N 

Baseline value (SD) 27 58.2 7.1 23 Final value (SD) 27 59.3 6.4 23 Difference P Difference NS NS Net Difference P Net difference NS Outcome Performance IQ (nd) 

 N B12 N 

Baseline value (SD) 27 74.9* 13.1 23 Final value (SD) 27 80.7 12.0 23 Difference P Difference <0.005 NS Net Difference P Net difference NS * Significant difference between intervention and control group at baseline. When demented patients (n= 7 B12, 3 Control; Diagnosed by psychogeriatrician or MMSE<20), no difference in cognitive test results. 

Among the 7 demented subjects who received cobalamin,  1 improved on the MMSE from 18 to 21, digit span, verbal memory, and performance IQ  1 improved on the MMSE from 19 to 24, verbal IQ, and performance IQ  1 improved on the MMSE from 5 to 9, and verbal memory  4 showed no “significant” improvement  None improved on visual memory test. 
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Intervention

Author, Year: Lehmann, 2003 Ref ID: 1820 Vitamins: 

Objective: Effect of multi-B vitamin on cognition and CSF-tau in mildly cognitively impaired 

Study characteristics Population Controls Inclusion criteria Exclusion cr

Study design Prospective 

cohort 

Age: 72 

(59-81) 

Country: Sweden %Male: 57% Setting: Memory unit Race: nd Funding: Pharmaceutical Other: 

Ambulatory, complaining of cognitive disturbances, MMSE 24-30, Serum Hcy >13.5 nmol/L 

Serum Cr >120 μmotreatment with a choinhibitor 

Comments: Intervention(s): Control: Total Intervention 1 Intervent

N enrolled: 30 30 N analyzed: 30 30 

Vit B12 1 mg po BID Folate 5 mg po BID Pyridoxine 40 mg po BID Drop-outs (%): Follow-up duration: Mean 270 (110-740) days Reasons for drop out: Comments: Primary outcome(s): MMSE, CSF-tau Secondary outcome(s): CSF Albumin rati:, serum Hcy, B12, folate Adverse events: nd Limitations: Quality (A/B/C): C Applicability (1/2/3): 2 Outcome(s): Results (Text) (or Definition) MMSE CSF-tau sandwich ELISA with Innotest hTAU-Ag, measuring both normal and hyperphosphorylated tau 
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Outcome MMSE (0-30) 

 N B6/B12/Folate 2/10/80 mg 

Baseline value (SD) 30 26.3 (1.8) Final value (SD) 30 26.4 (2.4) Difference P Difference NS Net Difference (SE/SD/95% CI) P Net difference Outcome CSF-tau pg/mL 

 N B6/B12/Folate 2/10/80 mg 

Baseline value (SD) 30 529 (242) Final value (SD) 30 490 (240) Difference P Difference NS Net Difference (SE/SD/95% CI) P Net difference At baseline CSF-tau was “considerably increased” compared to a non-cognitively impaired control group (222+/-92 pg/mL, n=35). 
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Intervention

Author, Year: Martin, 1992 Ref ID: 10009 Vitamins: 

Objective: Cognitive effects of cobalamin replacement in patients suffering from cognitive impairment and low serum cobalam

Study characteristics Population Controls Inclusion criteria Ex

c

Study design Cohort Age: 79 Country: USA %Male: 22 Setting: Outpatient geriatric centers, inpt 

geropsychiatry unit, tertiary care university hospital 

Race: ND 

Funding: Government Other: 

Consecutive enrollment of cognitive impaired, serum cobalamin < 150 pmol/L 

ND 

Comments: Intervention(s): Control: Total Intervention 1 Intervent1000 mcg cyanocobalamin intramuscular 1 at day for 1 wk, weekly for 1 mo, monthly ≥ 6 mo 

N enrolled: 22 N analyzed: 18 Drop-outs (%): 4 

Follow-up duration: Reasons for drop out: Died (2), unable to test due to: dementia (1)Comments: Potential confounders: 3 Pts w/concomitant low serum folate also received oral folate replacement 1 mg @ day, 1 pt on 

start of study, 4 pts on tricyclic antidepressant but was not new change in regimen 

Primary outcome(s): Changes in DRS scores pre vs post therapy Secondary outcome(s): Comparison of DRS scores by short vs long pretreatment symptom duration Adverse events: nd Limitations: Quality (A/B/C): C Applicability (1/2/3): 1 Outcome(s): Definition Mattis DRS Mattis Dementia Rating Scale. Used to evaluate pre & post therapy(≥ 6 mo), pts referred by primary physicians

status test with following criteria: mild impaired – 120-134, moderately impaired 90-119, severely impaired ≤ 9
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Outcome(s): Results DRS scores 11/18 improved (61%) Outcome DRS Short duration symptoms Long duration symptoms 

 N Cobalamin 1000 mcg N Cobalamin 10

Baseline value (SD) 5 108 (10) 13 108 (19) Final value (SD) 128 (13) 105 (22) Difference (SE/SD/95% CI) P = .0076 P = 0.34 P Difference Net Difference (SE/SD/95% CI) P Net difference (RR/OR/HR) 95% CI P (RR/OR/HR) 
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C-67 

Intervention

Author, Year: McGeer, 1972 Ref ID: 2107 Vitamins: 

Objective: Effect of folate on PD 

Study characteristics Population Controls Inclusion criteria Exclusion criter

Study design Cohort (design unclear) Age: nd Country: Canada %Male: nd Setting: Clinic Race: nd Funding: nd Other: 

Parkinsonian patients 

Comments: Intervention(s): Control: Total Intervention 1 InterventFolic acid 15 mg qD N enrolled: nd 

N analyzed: 18 18 Drop-outs (%): 

Follow-up duration: Mean 45 (14-182) Reasons for drop out: Comments: Primary outcome(s): Therapeutic benefit Secondary outcome(s): Adverse events: “Only 3 patients reported any adverse effects. One experienced a buzzing in the ears, another a jittery fee

sleeplessness.” No mental changes, weight loss, or gastrointestinal symptoms. 

Limitations: Quality (A/B/C): C Applicability (1/2/3): 2 Outcome(s): Results (Text) (or Definition) Therapeutic benefit 6: No therapeutic benefit 

11: A slight subjective benefit (without appreciable objective change) 

1: Worsening of gait. 
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C-68 

Intervention

Author, Year: Meador, 1993 Ref ID: 2127 Vitamins: B1 

Objective: The effect of 3-8 mg/d of thiamine in patients with Alzheimer’s disease 2 Studies Study 1: Study characteristics Population Inclusion criteria Exclusion criteria Study design Randomized 

cross-over 

Age: 71 

(61-86) 

Country: US %Male: 28% Setting: Free-living Race: nd Funding: Government Other: 

Meeting standard criteria for 

probable diagnosis of AD. All patients were living with devoted caretaker 

h/o alcohol, drug abuse, lab evidence of malnutrition, medications for CNS activity. 

Comments: A double blind placebo controlled cross-over trial with no wash out period Intervention(s): Control: Total Intervention 1 InterveThiamine 3 g/d N enrolled: 18 18 

N analyzed: 13-17 

Placebo 

Drop-outs (%): 

Follow-up duration: 1 mo Reasons for drop out: ND Comments: Primary outcome(s): Mean Alzheimer’s Disease Assessment scale score;; Mini-mental status exam Secondary outcome(s): Single fiber EMG; The Clinical Global Impression of change (Physician rating of change from baAdverse events: No adverse effects were noted Limitations: Small N, Poor reporting Quality (A/B/C): C Applicability (1/2/3): 2 
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ADAS 0-120 (higher score = poorer performance) 

 N Thiamine 3g/d N 

Baseline value (SD) 17 36 25 17 Final value (SD) 17 41 27 17 Difference (SE/SD/95% CI) +2.1* +6.7 P Difference nd nd Net Difference (SE/SD/95% CI) P Net difference nd *These numbers are from text. Unclear why they do not correspond to reported data. MMSE 0-30 

 N Thiamine 3 g/d N 

Baseline value (SD) 17 18 7 17 Final value (SD) 17 18 7 17 Difference (SE/SD/95% CI) 0 -1 P Difference NS ND Net Difference (SE/SD/95% CI) +1 P Net difference nd Text: ADAS scores better in thiamine period than control in 13/17 subjects (P=0.02) ADAS on thiamine worse than baseline in 9/16 (NS) ADAS on placebo worse than baseline in 12/16 (P=0.04) Implicitly 1 patient each scored the same as at baseline during different periods. MMSE scores were better in thiamine period than control in 6/8 (NS) MMSE on thiamine worse than baseline in 9/13 (NS) MMSE on placebo worse than baseline in 11/14 (P=0.03) Implicitly 9 patients scored the same in both periods and 4 on thiamine and 3 on placebo scored the same as at baseline during different 
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Study 2: Study characteristics Population Inclusion criteria Exclusion criteria Study design Prospective, longitudinal 

cohort, with multiple oneway crossovers 

Age: 69 

(54-93) 

Country: US %Male: 53% Setting: Free-living Race: nd Funding: Government Other: 

Meeting standard criteria for probable diagnosis of AD. All patients were living with devoted caretaker 

h/o alcohol, drug abuse, lab evidence of malnutrition, medications for CNS activity. 

Comments: 6 of the subjects also participated in the randomized cross-over study, with at least 3.5 months between trials. Intervention(s): Control: Total Intervention 1 InterveThiamine, 4-6 g N enrolled: 17 17 

N analyzed: 14-17* 

Placebo 

Drop-outs (%): 

Follow-up duration: 1 mo each at 4, 5, 6 g, and 

placebo 

Reasons for drop out: nd 

Comments: * Subsequent phases of trial included 2-13 subjects at “best dose” and between 6.5-8 g Primary outcome(s): Mean Alzheimer’s Disease Assessment scale score;; Mini-mental status exam Secondary outcome(s): Single fiber EMG; The Clinical Global Impression of change (Physician rating of change from baAdverse events: All tolerated doses up to 6 g/day well without any side effects. 

2 (of 7) subjects reported nausea and indigestion at doses of 7.0 and 7.5 g/day but subsequently toin later months. 

Limitations: Quality (A/B/C): C Applicability (1/2/3): 2 
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Phase 1: Open titration, from 4-6 g/dayADAS 0-120 Month 1 Mo N Thiamine 4 g N Baseline value* 16 27.2 13 Final value 16 23.4 13 Difference P Difference P≤0.01 NS ADAS 0-120 Month 2 Mo N Thiamine 5 g N Baseline value* 16 27.2 13 Final value 16 23.7 13 Difference P Difference P≤0.055 NS ADAS 0-120 Month 3 Mo N Thiamine 6 g N Baseline value* 16 26.6 13 Final value 16 24.3 13 Difference P Difference NS NS * Baseline means for subjects analyzed in each group. 
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MMSE 0-30 Month 1 Mo N Thiamine 4 g N Baseline value* 17 21.2 15 Final value 17 21.7 15 Difference P Difference NS NS MMSE 0-30 Month 2 Mo N Thiamine 5 g N Baseline value* 17 21.2 15 Final value 17 21.8 15 Difference P Difference NS NS MMSE 0-30 Month 3 Mo N Thiamine 6 g N Baseline value* 15 21.2 15 Final value 15 21.7 15 Difference P Difference NS NS * Baseline means for subjects analyzed in each group. Text: In a month of best dose (month 5) ADAS and MMSE, difference compared to baseline was non-significant (n=13 & 15, respectively).In months at 6.5 and 7 g/day (months 6,7) ADAS significantly better compared to baseline (P≤0.015 & P≤0.002, respectively; n=6). 

In months with dose varying from 6.5-8 g/day (months 8, 9, 11, 13) ADAS no different than baseline (n=2-6). MMSE were unchanged throughout the remainder of the study in 2-7 subjects. 
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C-73 

Intervention

Intervention(s): Control: Total Intervention 1 Intervent

Fursultiamine 100 mg/d in 2 divided doses 

N enrolled: 9 8 NA N analyzed: 9 9 

NA 

Drop-outs (%): 11% (1/9) 

Follow-up duration: 12 wk Reasons for drop out: Family commitments Comments: 1 patient that did not complete the study was included in the analysis 

Thiamine measured using HPLC method 

Author, Year: Mimori, 1996 Ref ID: 2176 Vitamins: Objective: To examine the beneficial effect of fursultiamine, in patients using a battery of tests of cognitive function 

Study characteristics Population Controls Inclusion criteria Exclusion criter

Study design Open noncomparative 

trial 

Age: 71.8±6.3 

Country: Japan %Male: 44% Setting: University 

hospital 

Race: 100% Asian 

Funding: Private Other: Mean duration 

of illness: 

2.3±1.4 yr 

All outpatients who met the DSM-III/R criteria for dementia and the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer’s Disease and Related Disorders Association (NINCDSADRDA) 

ND 

Comments: Fursultiamine (thiamine tetrahydrofurfuryl disulfide hydrochloride (TTFD) a derivative of thiamine which is eas

active form of thiamine in the body 
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Primary outcome(s): Hasegawa Dementia Scale (HDS) Total score 32.5 

better performanscreening tests of Japan along with 

Primary outcome(s): Mini-Mental State Examination (MMSE) Total score 30 (h

better performan

Primary outcome(s): Rating scale by Gottfries (Modified GBS) Total score 228 (

better function) Assesses intellecemotional functioother symptoms 

Secondary outcome(s): Blood level of thiamine Adverse events: All patients tolerated the drug and dosages well Limitations: Small sample size Quality (A/B/C): C Applicability (1/2/3): Outcome(s): Results (Text) (or Definition) Blood level of thiamine 

Baseline Mean blood level of thiamine: 32.5±11.3 (19.5 to 49.3 ng/mL and within normal limits. Among patien

thiamine levels 1 patient showed some improvement and 1 did not. Blood thiamine levels increased markedly a

(257.4±99.4 ng/mL) 

HDS Hasegawa Dementia Scale 0-32.5 

 N Fursultiamine 100 mg/d in 2 divided doses

Baseline value (SD) 9 17.0 (9.7) Final value (SD) 9 17.6 (10.4) Difference (SD) 0.6 (0.7) P Difference NS Net Difference (SE/SD/95% CI) P Net difference (RR/OR/HR) 95% CI P (RR/OR/HR) 
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MMSE Mini-Mental State Exam 0-30 

 N Fursultiamine 100 mg/d in 2 divided doses

Baseline value (SD) 9 17.2 (7.0) Final value (SD) 9 19.4 (9.0) Difference (SD) 2.2 (2.0) P Difference <0.05 Net Difference (SE/SD/95% CI) P Net difference (RR/OR/HR) 95% CI P (RR/OR/HR) Total GBS Gottfries (Modified GBS) 0-228 

 N Fursultiamine 100 mg/d in 2 divided doses

Baseline value (SD) 9 59.8 (38.5) Final value (SD) 9 52.4 (41.8) Difference (SD) -7.4 (3.3) P Difference <0.1(NS) Net Difference (SE/SD/95% CI) P Net difference (RR/OR/HR) 95% CI P (RR/OR/HR) 
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Intervention

Author, Year: Mitsuyama, 1988 Ref ID: 2185 Vitamins: 

Objective: To examine the effect of CH3-B12 on the CNS and clinical effectiveness for organic mental symptoms. To determin

the serum vitB12 and CSF vitB12 

Study characteristics Population Controls Inclusion criteria Exclusion criteria 

Study design Non 

comparative open trial and correlational study 

Age: 53±3.1 

(34-77) 

Country: Japan %Male: 64% Setting: Academic 

hospital 

Race: 100% 

Asian 

Funding: ND Other: 

Subjects who fulfilled the clinical criteria of dementia. Confirmed in all patients by the finding of cerebral atrophy and widening of the ventricles on the CT scan. 

Any disorder known to affect vit B12 metabolism, such as acute physical disease, malnutrition, severe anemia, and myeloproliferative disorders and abnormal kidney and liver disorders 

Comments: 4 patients were mildly demented; 7 moderately demented; 3 patients were severely demented 

Intervention(s): Control: Total Intervention 1 Intervent

Vit B12 2mg/d for 60d N enrolled: 14 5 9 Vit B12 2 mg/d PO and 500μg/d IM 

N analyzed: 14 5 9 

None 

Drop-outs (%): 0 

Follow-up duration: 60 days Reasons for drop out: NA Comments: Sr and CSF B12 assessed by radioassay range between 25 to 1600 pg/mL 
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Primary outcome(s): Change in GBS scale (a neuropsychological scale developed by Gottfries) Correlation between sSecondary outcome(s): Correlation of sr and CSF-VB 12 with severity of dementia Adverse events: ND Limitations: Small sample size (only 1 patient with AD and W-K); 1 patient had unclassified presenile dementia; a

disease 

Quality (A/B/C): B (comparative trial and small sample size) Applicability (1/2/3): 2 Broad range of dOutcome(s): Results (Text) (or Definition) Correlation of Serum and CSF Vit B12 with severity of dementia 

No correlation between the concentration of serum and CSF vit B12 levels and severity of dementia w

Change in GBS scale No change in GBS scale with administration of CH3-B12. However patients on both PO and IM repo

mood and social behavioral changes and enhanced self rating of competencies 
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Intervention

Author, Year: Nilsson, 2000 Ref ID: 2338 Vitamins: 

Objective: A study on dementia patients with specific aim to investigate the relation between B12 deficiency, clinical changes 

Study characteristics Population Controls Inclusion criteria Exclusion criteria Defin

Study design Nonrandomized 

trial 

Age: 79.8 

(6.2) 

No 

controls 

AD: wlate onse

Country: Sweden %Male: 50% PD: Setting: University 

hospital 

Race: Probably 

white 

Vasc

Funding: Private 

foundationNon Industry 

Other: 

Patients selected from consecutive admissions to the psychogeriatric department and those with low serum cobalamin level (155 pmol/L) detected during the diagnostic examination were included 

Those with acute or unstable physical conditions and recent cerebrovascular accidents 

Othe

Comments: Intervention(s): Control: Total Intervention 1 InterventHydroxycobalamin 1 mg every second day x 10 times and thereafter 1 mg/month 

N enrolled: 29 24 N analyzed: 24 24 

None 

Drop-outs (%): ND 

Follow-up duration: 1 month / 1 wk for MMSE Reasons for drop out: Comments: Final data includes both vasc dementia, AD and mixed dementia Sr cobalamin determined using radioassay and reference limit 110-650 pmol/L and 155 pmol/L as the lower reference limit for cobalam
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Primary outcome(s): Clinical improvement; MMSE score improvement; Cerebral blood flow Secondary outcome(s): Hcy, MMA Adverse events: ND Limitations: Includes patients with delirium. Delirium could be secondary to dementia and as due to cobalamin defici

enrollment 

Quality (A/B/C): C Applicability (1/2/3): 2 Outcome(s): Results (Text) (or Definition) Clinical improvement 

The 15 patients who responded to cobalamin treatment were judged to be demented to about the same degree aalthough behavioral symptoms diminished. The improved group had mild to moderate dementia at baseline 

Cerebral blood flow The improved group of patients (n=15) had a significant higher value compared to baseline after 1 month. 

The group of patients with no or little clinical improvement showed non significant decrease after 1 month 

Regional cerebral blood flow 

There was no significant difference in the rCBF pattern between clinically improved and non-improved cases aThe clinically improved patients showed a general flow increase and regional central temporal blood flow incre

(p<0.05) The non responders to cobalamin treatment showed a flow increase in primarily sensory motor areas after 1 mopronounced central lobe rCBF increase after a longer period of treatment than did the clinically improved group 

MMSE Only 10 patients tested at 1 week, 2 AD, 3 mixed AD+vascular (5 vascular). No further extraction performed 
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Intervention

Author, Year: Nilsson, 2001 Ref ID: 2340 Vitamins: 

Objective: To investigate the effect of B12, folate supplementation on cognitive function in elderly patients with demtentia 

Study characteristics Population Controls Inclusion criteria Exclusion criteria Definitions 

Study design Noncontrolled 

trial 

Age: 78.4 

±8.1 

N/A AD:8 

Country: Sweden %Male: 42 N/A PD: Setting: University 

Hospital outpatients 

Race: ND N/A VascDz: 19 

Funding: Government, 

non-profit 

Other: 

Consecutive patients with symptoms of organic brain disease referred to a University Hospital for Dx examination and Tx 

Patients with acute or unstable conditions, with non-organic psychiatric disease, with ongoing Vit substitution 

Other: Frontotemporal dementia: 1; mixed AD with VascDz: 1; other specified: 2; non-specified2 

Comments: Intervention(s): Control: Total Intervention 1 InterventB12 per os 1mg/d N enrolled: 33 Folate per os 5mg/d N analyzed: 28 

N/A 

Drop-outs (%): 5 (15) 

Follow-up duration: 2 mo Reasons for drop out: Severely demented patients who could not c

before or after the Tx 

Comments: 
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Primary outcome(s): MMSE, SKT scores, GI Secondary outcome(s): Adverse events: ND Limitations: Small sample size (especially for Hcy subgroups) Quality (A/B/C): C Applicability (1/2/3): 2 Outcome(s): Results (Text) (or Definition) MMSE Total score may vary between 0 and 30, with lower scores indicating severe cognitive impairment SKT Short cognitive performance test for assessing memory and attention in the sense of info processing speed; con

limited to a max time 60 sec; total score varies between 0 to 27; higher scores indicate more severe cognitive im

Global impression of change (GI) 

It was made and documented by an experienced clinician according to a standardized clinical assessment and b

and caregivers. The patients were classified as globally improved (GI score=1) following supplementation whe/relatives reported improvements in alertness, orientation in time and space, recent memory and fewer clinical f

did not improve were classified as unchanged (GI score=0) Among patients with normal Hcy 2/11 improved wincreased Hcy 14/17 improved 
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Patients with normal Hcy MMSE Score 

 N B12 1mg/d N Folate 5mg/d N (Intervention) (Dos

Baseline value (SE/SD) 11 21.3 4.9 11 21.3 4.9 Final value (SE/SD) 11 20.9 4.7 11 20.9 4.7 Difference (SE/SD/95% CI) -0.4 ND -0.4 ND P Difference NS NS Net Difference (SE/SD/95% CI) P Net difference (RR/OR/HR) 95% CI P (RR/OR/HR) Serum B12 and blood folate concentration were determined by immunoassay using purified intrinsic factor and purified folate binding Amersham, UK). The reference intervals for B12 are 110-650 pmol/L and for folate 125-500 nmol/L Unclear whether SD or SE is reported Patients with increased Hcy MMSE Score 

 N B12 1mg/d N folate 5mg/d N (Intervention) (Dos

Baseline value (SE/SD) 17 17.2 8.3 17 17.2 8.3 Final value (SE/SD) 17 21.4 4.7 17 21.4 4.7 Difference (SE/SD/95% CI) +4.2 ND +4.2 ND P Difference <0.01 <0.01 Net Difference (SE/SD/95% CI) P Net difference (RR/OR/HR) 95% CI P (RR/OR/HR) Serum B12 and blood folate concentration were determined by immunoassay using purified intrinsic factor and purified folate binding Amersham, UK). The reference intervals for B12 are 110-650 pmol/L and for folate 125-500 nmol/L Unclear whether SD or SE is reported 
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Patients with normal Hcy SKT Score 

 N B12 1mg/d N Folate 5mg/d N (Intervention) (Dos

Baseline value (SE/SD) 11 15.6 4.5 11 15.6 4.5 Final value (SE/SD) 11 14.8 4.9 11 14.8 4.9 Difference (SE/SD/95% CI) -0.8 ND -0.8 ND P Difference NS NS Net Difference (SE/SD/95% CI) P Net difference (RR/OR/HR) 95% CI P (RR/OR/HR) Serum B12 and blood folate concentration were determined by immunoassay using purified intrinsic factor and purified folate binding Amersham, UK). The reference intervals for B12 are 110-650 pmol/L and for folate 125-500 nmol/L Unclear whether SD or SE is reported Patients with increased Hcy SKT Score 

 N B12 1mg/d N Folate 5mg/d N (Intervention) (Dos

Baseline value (SE/SD) 17 18.5 5.5 17 18.5 5.5 Final value (SE/SD) 17 14.6 4. 35 17 14.6 4. 35 Difference (SE/SD/95% CI) -3.9 ND -3.9 ND P Difference <0.01 <0.01 Net Difference (SE/SD/95% CI) P Net difference (RR/OR/HR) 95% CI P (RR/OR/HR) Serum B12 and blood folate concentration were determined by immunoassay using purified intrinsic factor and purified folate binding Amersham, UK). The reference intervals for B12 are 110-650 pmol/L and for folate 125-500 nmol/L Unclear whether SD or SE is reported 
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Intervention

Author, Year: Nolan, 1991 Ref ID: 2360 Vitamins: B1 

Objective: To determine efficacy of B1 supplementation on cognitive function tests Study characteristics Population Controls Inclusion criteria Exclusion criteria Definitions Study design RCT 

(Doubleblind) 

Age: Total (N=15) mean 

76.3 Range 59-87 

AD: Prob

defiADthe 

Country: US %Male: Total (N=15) 33 PD: Setting: Nursing 

home and outpatient clinic 

Race: ND ND VascDz:

Funding: Government 

/non-profit 

Other: 

Patients from geriatric Evaluation Service (subspecialty clinic) who had clinical Dx of probable or possible AD 

ND 

Other: 

Comments: Population characteristics are not given separately for the 2 comparative groups Intervention(s): Control: Total Intervention 1 InterventB1 (HCL) as caps of 1g each N enrolled: 15 ND Dose 3g/d (3 capsules) N analyzed: 10 5 

Placebo: lactose (Caps of the same appearance, size, and weight as intervention) Drop-outs (%): 5 (33) 8 (14) 

Follow-up duration: 12 months Reasons for drop out: Poor compliance: 3; health problems unrela

protocol violation 

Comments: An additional analysis was performed including 2 patients who had complete data only for 9 mo (Total N: 12; 6 intervenPrimary outcome(s): MMSE Secondary outcome(s): Verbal fluency, short (15-item) Boston naming test; constructional praxis test; 10-item word list le

and recognition 

Adverse events: ND Limitations: Small sample size; randomization method not described; power calculation not reported; intention-to-treat analysis no

relatively high drop-out rate (33%) 

Quality (A/B/C): C Applicability (1/2/3): 1 
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Outcome(s): Results (Text) (or Definition) CERAD Patients were seen at 3-mo intervals The CERAD (Consortium to Establish a Registry for AD) neuropsycholog

administered to each patient by the same examiner at each visit, including the baseline visit. This battery includ

referred as primary and secondary outcomes above: Verbal fluency, Short (15-item) Boston naming test, MMStest, 10-item word list learning test, Recall and Recognition tests 

Verbal fluency Verbal learning scores at 12 mo were significantly lower than those at 3 mo and baseline (p<0.05). When 12 pa

(follow-up: 9 mo), the verbal learning scores at 9 mo were significantly lower than those at all other observatio

Short (15-item) Boston naming test 

Mean naming scores at 12 mo were significantly lower than those at all other observations (p<0.05). The mean 

were significantly lower than those at all earlier observations (p<0.05) 

MMSE A 2-way (group x time) repeated ANOVA measures obtained at the 5 clinic visits indicated NS difference betw

groups. The mean MMSE score at mo 3, 6, 9, 12 were significantly lower than baseline (p<0.05). The mean MMsignificantly lower than those at all other observations (p<0.05). The mean MMSE scores at 9 mo were signific

all earlier observations (p<0.05). When 12 patients included in analyses (follow-up: 9 mo), the mean MMSE scsignificantly lower than those at all other observations (p<0.05). 

Constructional praxis test 

NS difference between groups 

10-item word list learning test 

Verbal learning scores at 12 mo were significantly lower than those at 3 mo and baseline (p<0.05). 

Recall test Delayed recall scores were not formally analyzed, due to floor effects; only 3 /10subjects were ever able to reca

the 10-word lists, and the most frequent score was 0. 

Recognition test Delayed recognition scores between groups, NS. All Subjects Outcome MMSE ND 

 N B1 3g/d N (Intervention) (Dose) N (Intervention) (Do

Baseline value (SE/SD) 5 16.6 5.73 Final value (SE/SD) 5 10.4 9.13 Difference (SE/SD/95% CI) -6.2 <0.05 P Difference ND Net Difference (SE/SD/95% CI) -4.8 ND P Net difference ND 
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Intervention

Author, Year: Rapin, 1988 Ref ID: 10015 Vitamins: 

Objective: Effect of folate treatment on cognitive function 

Study characteristics Population Inclusion criteria Exclusion criteria 

Study design Prospective single 

cohort 

Age: 62+/-

5 

Country: France %Male: nd Setting: nd Race: nd Funding: nd Other: 

RBC folate<300 ng/mL. “All patients have memory disorders with fatigability and disinterest for life.” 

Megaloblastic marrow organic diseases. 

Comments: Intervention(s): Control: Total Intervention 1 InterventFolinic acid, 50 mg/week po N enrolled: nd 

N analyzed: 38 

(none) 

Drop-outs (%): 

Follow-up duration: 120 days Reasons for drop out: Comments: Primary outcome(s): 16 scales that are either not defined or poorly defined. Other outcome(s): Depression scale Adverse events: nd Limitations: Very poor reporting Quality (A/B/C): C Applicability (1/2/3): 2 
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Outcome(s): Definition PRM 4 from Rey nd PRM 6 from Rey analyzes different stages of memorization visuo verbal, learning capacity, immediate and delayeBenton’s VRT evaluates visuo-spatial memory 3 words of Luria analyzes verbal interferences Porteus maze gives an assessment of perception and visuo-spatial organization Reaction time test, visual gives an assessment of psychomotor coordination ability Reaction time test, auditory gives an assessment of psychomotor coordination ability Reaction time test, mixed gives an assessment of psychomotor coordination ability PRM 7 from Rey nd Video coupled object test measures associative memory 15 words of Rey Verbal learning tests Daily activities test nd Compound series of Morisby evaluates logical reasoning Porteus maze delayed studies recall of visuo spatial memory Video coupled object, delayed no specific definition Overlapped drawing by Rey measures perception and ability to discriminate the figures Results are displayed graphically, measured as % of deficit compared to separately analyzed age-matched healthy individuals. Outcome(s): Results Cognitive tests There were significant improvements in the following tests: 

 Benton’s VRT; Porteus maze; Video coupled object test; Daily activities test; Compound series of Mo

Other tests showed no difference from baseline to 120 days of treatment. 
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Intervention

Author, Year: Seal, 2002 Ref ID: 10017 Vitamins: 

Objective: B12 supplementation in elderly. Determination of minimum dose to restore normal serum B12 

Study characteristics Population Controls Inclusion criteria Exclusion criteria 

Study design RCT Age: 82.0 84.9 77.6 Country: Australia %Male: 40% 50% 45% Setting: Geriatric 

center 

Race: nd nd nd 

Funding: Hospital Other: ~1/3 had dementia (not 

defined); ~1/2 had cerebrovascular or cardiovascular disease 

Resident in geriatric center or extended care facility, subnormal serum B12 (between 100-150 pmol/L) 

None had a previous histogastric or bowel surgery osymptoms to suggest malaKnown neoplasm, terminahistory or diagnosis of malabsorption, pernicious other anemia, prior B12 osupplementation. 

Comments: Double blind Intervention(s): Control: Total B12 10 μg B12 50 μg ControlVitamin B12 10 μg daily N enrolled: 10 10 11 Vitamin B12 50 μg daily N analyzed: 9 10 8 

Placebo 

Drop-outs (%): 0 

Follow-up duration: ~4 wk (mean 31 days, range 27-39) Reasons for drop out:Comments: Primary outcome(s): Serum B12 Secondary outcome(s): Mini Mental Status Exam (MMSE), folate, homocysteine, hemoglobin, mean corpuscular volume Adverse events: nd Limitations: Quality (A/B/C): B Applicability (1/2/3): 1 Outcome(s): Results (Text) (or Definition) 
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C-89 

(Separate table for each outcome) Outcome MMSE (0-30) 

 N B12 10 μg N B12 50 μg 

Baseline value* (SD) 9 15.4 (7.8) 10 19.7 (5.3) Final value 9 9 Difference (SD) 0 (2.9) +1 (3.2) P Difference NS (0.49)** Net Difference (SE/SD/95% CI) P Net difference * Baseline values not significantly different from each other. ** ANOVA, comparing all 3 groups simultaneously. 
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C-90 

Intervention

Author, Year: Sommer, 2003 Ref ID: 3063 Vitamins: 

Objective: Folate supplementation for dementia 

Study characteristics Population Inclusion criteria Exclusion criteria 

Study design RCT Age: 77 

(68-80) 

Country: US %Male: 57% Setting: Community Race: nd Funding: nd Other: 

Age ≥65 yr, Dementia (DSM-III R), serum folate 2-5 μg/L, RBC folate 127-452 μg/L, B12>200 ng/L. (Refrained from vitamin supplementation for at least 1 mo prior to study.) 

Seizure disorder, major depression or need for antidepressant medication 

Comments: Dx: Probable AD, 3; Dementia not otherwise specified, 2; Lewy body dementia, 1; vascular dementia, 1 

Baseline MMSE: mean 20.4 (range 14-27) 

Intervention(s): Control: Total Intervention 1 Intervent

N enrolled: 11 5 N analyzed: 7 4 

Folic acid 10 mg BID Placebo 

Drop-outs (%): 36% 

Follow-up duration: 10 wk Reasons for drop out: Tx: Dropped out (did not return calls); Cx: C

care 1, nausea/diarrhea 1, scheduling difficu

Comments: Double blind, pill counting performed. One of dropouts apparently described in wrong arm. 
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Language: 

 WAIS-R: Pro-rated Verbal IQ measure of intellectual function  Boston Naming Test object-naming, detect difficulties in confrontat Controlled Oral Word Association Test verbal fluency Memory:  Wechsler Memory Scale (WMS):Logical Memory Subtest 

short-term vocabulary 

 WMS: Associate Learning Subtest short-term vocabulary Speed/Concentration:  Trails A and B visual scanning, conceptual flexibility, motor s

Primary outcome(s): 

 Finger Tapping Test pure motor speed 

Secondary outcome(s): Adverse events: “Safe and well-tolerated.” Limitations: 1/7 subjects with vascular dementia. Very small N. High dropout. Quality (A/B/C): C Applicability (1/2/3): 1 Outcome(s): Results (Text) (or Definition) All The magnitude of change between baseline and second testing was not statistically significant for folic acid and 

There was a trend for the folic acid group to perform worse than the placebo group on the Associate Learning STrails B (P<0.08), which suggest a trend toward a worsening of cognitive abilities secondary to the folic acid s

Specifically, verbal memory and perceptual motor speed may have been negatively affected. 

Outcome WAIS-R: Pro-rated Verbal IQ (Normal mean = 100) 

 N Folic acid 20 mg N 

Baseline value (SD) 4 107.8 (12.8) 3 Final value (SD) 4 105.3 (16.7) 3 Difference P Difference Net Difference P Net difference 0.81 
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Outcome Boston Naming Test (nd range) 

 N Folic acid 20 mg N 

Baseline value (SD) 4 40.8 (19.7) 3 Final value (SD) 4 42.0 (22.7) 3 Difference P Difference Net Difference P Net difference 0.86 Outcome Controlled Oral Word Association Test (nd range) 

 N Folic acid 20 mg 

Baseline value (SD) 4 29.5 (10.5) Final value (SD) 4 32.8 (14.9) Difference P Difference Net Difference P Net difference 0.48 Outcome Wechsler Memory Scale: Logical Memory Subtest (nd range) 

 N Folic acid 20 mg 

Baseline value (SD) 4 4.9 (2.0) Final value (SD) 4 4.9 (2.5) Difference P Difference Net Difference P Net difference 0.28 Outcome Wechsler Memory Scale: Associate Learning Subtest (nd range) 

 N Folic acid 20 mg 

Baseline value (SD) 4 16.6 (2.5) Final value (SD) 4 9.5 (3.0) Difference P Difference Net Difference P Net difference 0.08 
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Outcome Speed/Concentration: Trails A (seconds, nd normal) 

 N Folic acid 20 mg N 

Baseline value (SD) 4 233.0 (249.3) 3 Final value (SD) 4 247.8 (256.2) 3 Difference P Difference Net Difference P Net difference 0.16 Outcome Speed/Concentration: Trails B (seconds, nd normal) 

 N Folic acid 20 mg N 

Baseline value (SD) 4 373.0 (263.7) 3 Final value (SD) 4 393.3 (239.3) 3 Difference P Difference Net Difference P Net difference 0.08 Outcome Speed/Concentration: Finger Tapping Test (nd range) 

 N Folic acid 20 mg 

Baseline value (SD) 4 38.4 (9.2) Final value (SD) 4 37.9 (8.8) Difference P Difference Net Difference P Net difference 0.56 
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Intervention

Author, Year: Teunisse, 1996 Ref ID: 3238 Vitamins: 

Objective: Effect of B12 repletion on dementia 

Study characteristics Population Inclusion criteria Exclusion criteria 

Study design Prospective 

longitudinal cohorts 

Age: 77.5+/-

5.3 

Country: Netherlands %Male: 42% Setting: Clinic Race: nd 

Duration of symptoms: 

45+/-32 

mo 

Funding: Government 

B12 150 

(35-195) 

Age ≥65 yr, suspected 

dementia by general practitioner. Diagnosis of dementia by DSM-III-R criteria. Serum B12 <200 pg/L 

Previous neurological, neuroradiological examination or extensive diagnostic laboratory investigation for the same complaints. Serious co-morbidity precluding follow-up 

Comments: Study also evaluated a “reference group” of subjects with normal B12. This group not treated. Not included here. Intervention(s): Reference: Total Intervention 1 Intervent

N enrolled: 108 26 N analyzed: 19 

Cobalamin 1000 μg qD x 5 days, then qMo, or 1000 μg qWk x 5 days, then bi-monthly 

No treatment 

Drop-outs (%): 27% 

Follow-up duration: Mean+/-SD: 214+/-64 days Reasons for drop out: 1 not treated as advised, 1 stroke, 2 died, 3 m

available. (2 also were not cooperative with 

Comments: All but 1 of 26 with subnormal B12 fulfilled criteria for possible AD (1 also had cerebral infarctions). Primary outcome(s): Cognitive impairment, disability in ADL, behavioral changes Secondary outcome(s): Caregiver burden Adverse events: nd Limitations: Quality (A/B/C): C Applicability (1/2/3): 2 CAMDEX, Dutch version of the Cambridge Examination for Mental Disorders of the Elderly 
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C-95 

Outcome(s): Definition CAMCOG Subscale of CAMDEX, assesses orientation, language, memory, praxis, attention, abstract thinking, perception 

MMSE) 

IDDD Interview for Deterioration in Daily living activities in Dementia, caregiver assessment of functioning in the pa

initiative and performance (assistance necessary) 

RMBPC Revised Memory and Behavioral Problems; 3 subscales for memory, depression (not included here), and disrupB12 intervention Test Scale 

 N CAMCOG (0-106*) N IDDD-Init (36-0**) N IDD

Baseline value SD 19 64.9 15.7 19 13.8 9.2 19 12.7 Final value 17 19 19 Difference*** 95% CI -1.4 -7.4, +4.6 -4.9 -9.4, -0.4 -7.8 P Difference NS <0.05 <0.05 B12 intervention Test Scale 

 N MMSE (0-30*) N RMBPC-Mem (28-0**) N RMB

Baseline value SD 19 17.5 7.2 19 17.5 5.0 19 4.4 Final value 17 19 19 Difference 95% CI -1.8 -3.5, -0.1 -0.4 -3.5, +2.7 -2.6 P Difference <0.05 NS <0.05 * High score reflects less deterioration ** High score reflects more deterioration *** Negative scores reflect deterioration, positive scores reflect improvement. Although not a true comparison to a control, compared to the reference group of 69 patients with dementia with normal serum were not treated), no significant difference in degree of deterioration. 
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C-96 

Intervention

Author, Year: van Asselt, 2001 Ref ID: 10005 Vitamins: 

Objective: B12 for cognitive function in B12-deficient people 

Study characteristics Population Inclusion criteria Exclusion criteria 

Study design Prospective longitudinal 

cohort, Single cross-over with placebo 

Age: 71* 

(64-89) 

Country: Netherlands %Male: 44% Setting: Community Race: nd Funding: Government Other: 

Community-dwelling, “older,” plasma B12 ≤150 pmol/L (One subject had an MMSE score of 23) 

None had anemia, low serum or folate, myelopathy, history of Bdeficiency, B12 or folate supplesevere diseases, or severe cognitsensory problems 

Comments: *Median Intervention(s): Control: Total Intervention 1 Intervent

N enrolled: 16+2* N analyzed: 16 16 16 

Hydroxycobalamin 1 mg weekly x 4, then monthly x 4 IM 

Placebo (water injection, weekly x 4), prior to start of B12 treatment Drop-outs (%): 

Follow-up duration: 1 mo Placebo, then 5 mo B12 Reasons for drop out: * Comments: * 16 enrolled. 2 dropped out (1 protocol burdensome, 1 died of lung cancer). In their place, 2 other eligible people agreed to participatePrimary outcome(s): Biochemical, EEG, and neuropsychological tests Secondary outcome(s): Adverse events: nd Limitations: Quality (A/B/C): C Applicability (1/2/3): 2 Outcome(s): DMMSE nWAIS Forward and Backward Digit Span nVerbal Word Learning Test (immediate and delayed recall) nVerbal Fluency nSimilarities nTrail Making Test nRivermead Behavioral Face Recognition Test n(Geriatric Depression Scale) 
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C-97 

Outcome Verbal Word Learning Test (Delayed recall) (nd on range) 

 N B12 

Baseline MEDIAN (Range) 16 6 (1-11) Final MEDIAN (Range) 16 11 (2-14) Difference P Difference NS Net Difference P Net difference 0.03 * 1 month prior to B12 treatment Outcome Verbal Fluency (nd on range) 

 N B12 N 

Baseline MEDIAN (Range) 16 20 (14-22) 16 Final MEDIAN (Range) 16 18 (9-22) 16 Difference P Difference NS 0.003 Net Difference P Net difference 0.004 * 1 month prior to B12 treatment Outcome Similarities (nd on range) 

 N B12 N 

Baseline MEDIAN (Range) 16 7 (2-10) 16 SFinal MEDIAN (Range) 16 7 (2-10) 16 5 Difference P Difference NS 0.04 Net Difference P Net difference 0.05 * 1 month prior to B12 treatment Text: Performance on MMSE, Trail Making Test, Rivermead Behavioral Face Recognition Test, and Digit Span remained unchanged. 
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Intervention and Correlation

Author, Year: Bryan, 2002 Ref ID: 10004 Vitamins: 

Objective: To investigate the effects of short-term supplementation in healthy women who took either 750 μg of folate, 15 μg o

vitamin B6 or a placebo daily for 35 days 

Study characteristics Population Inclusion criteria Ex

c

Study design RCT, double-blind Age: 74.08±5.75 SD 

65-92 

Country: Australia %Male: 0 Setting: Population-based Race: ND Funding: Australian Association of 

Gerontology 

Education: 11.48±3.29 yr 

# of medical conditions: 1.96±1.58 

# of supplements: 0.59±1.00 

Random sample of females from 3 age bands whose names were selected from the Australian Electoral Rolls, which contains 98% of the adult voting population. Healthy women who did not smoke, who were not pregnant or lactating, not taking oral contraceptives or HRT, and not taking any medication likely to affect mental performance or mood. English as a first language, or proficiency in English. 

Misor ptreadat

Comments: This study has 3 age groups of women: younger age, middle-aged, and older women. We focus on older women. Intervention(s): Control: Total Intervention 1 Intervent

N enrolled: Younger: 56 

Middle: 80 

Older: 75 

Total: 221 

ND ND 

Folate 750 μg/day N analyzed: Total: 211 ND ND Vitamin B12 15 μg/day Drop-outs (%): 4.5% Vitamin B6 75 mg/day 

Placebo capsule 

Follow-up duration: 5 weeks Reasons for drop out: Incomplete data Comments: Compliance was monitoring by pill counting. The percentage of each treatment group who reported taking more than 95

folate, 96%; vitamin B12, 93%; vitamin B6, 94% and placebo, 88% 
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Primary outcome(s): Cognitive measures: 

1. Speed of processing: Boxes Test, a measure of sensory-motor speed; and the Digit Symbol-Cod

subtests of the Wechsler Adult Intelligence Scale-III (WAIS-III), both measures of perceptual s

2. Working memory: Digit Span-Backwards; Letter-Number Sequencing 3. Memory: Rey Auditory-Verbal Learning Test (RAVLT); and 2 measures of incidental recall: re

Digit-Symbol-Coding (WAIS-III) and Activity recall. 

4. Executive function: Executive function is conceptualized as a higher order cognitive function th

other cognitive activities involved in planning and implementing strategies for performance, mousing feedback to adjust future responding. Neuropsychological tests sensitive to frontal lobe fuincluding the Stroop Test; the Self-Ordered Pointing Task; Uses for Common Objects; The Trai

bal Fluency, comprising Initial Letter Fluency and Excluded Letter Fluency. 

5. Verbal ability: Vocabulary (WAIS-III) and Spot-the-Word. Mood measures: Current mood state was assessed using 2 self-report questionnaires that were comp

testing sessions: The Center for Epidemiological Studies-Depression Scale (CESD) and The ProfQuestionnaire (POMS) 

Secondary outcome(s): Effects of usual dietary intake on cognitive performance: Dietary intake at baseline was assessed using a 

quantified, FFQ based on Baghurst and Record. This form of the FFQ is regularly updated and has berepeatability and consistency with other dietary intake measurement techniques and has demonstrated with urinary and protein measures. The nutrient composition of the food item per unit weight were tak

British food tables. 

Adverse events: ND Limitations: Lack of objective measures of B vitamin status, such as RBC levels, at baseline or dose-response relation

Short duration. 

Quality (A/B/C): B Applicability (1/2/3): 1 Correlation of dietary usual intake of B vitamins and cognitive performance at baseline (or before supplementation) Outcome(s): Results (Text) (or Definition) Cognitive measures: 

1. Speed of 

processing 

2. Working 

memory 

3. Memory 4. Executive 

function 

5. Verbal ability 

Folate intake affected Boxes performance across age groups (p<0.05), with those in the 2nd intake quartile (

significantly more boxes than those in the 3rd (57.67±14.71) and 4th (55.94±16.49). There were no effect

on any other cognitive measure in older adults. 

There were no effects of vitamin B12 intake on any cognitive measure in older adults. There was an effect of vitamin B6 intake that interacted with age group for the short delay recall of the RA

age group participants in the 2nd (10.93±2.43) intake quartile recalling more words than those in the 1st (

effects of vitamin B6 intake on any other cognitive measure in older adults. 
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*Older participants had relatively better folate, vitamin B12, and vitamin B6 status than younger and middle-aged women, based on the 

Folate 

TUL 1000 μg 

RDI 200μg 

Vitamin B12 

TUL 20 μg 

RDI 2μg 

T

RD

Age group, year N Range, μg % < RDI % < 0.7 

RDI 

Range, μg % < RDI % < 0.7 

RDI 

Range, μg 

Younger (20-30) 56 98-668 29.1 12.7 0.37 20.0 9.1 0.7-4.3 Middle (45-55) 80 64-942 21.3 8.8 1-14 12.5 5.0 1.4-5.7 Older (65-92) 75 135-678 4.1 0 0.58-27 8.1 2.7 0.8-3.8 Total sample 221 64-942 17.2 7.2 0.37-27 12.9 4.8 0.4-5.7 TUL = tolerable upper limit; % < RDI = percentage of participants below the Australian Recommended Daily Intake (RDI); % < 0.7 Rparticipants below 70% of the Australian RDI Effects of short-term supplementation of B vitamins on cognitive performance at baseline Outcome(s): Results (Text) (or Definition) Cognitive measures: 

1. Speed of 

processing 

2. Working 

memory 

3. Memory 4. Executive 

function 

5. Verbal ability 

There were significant main effects of age and/or time for many of the cognitive performance in which per

positive with increasing age and at time 2 than time 1, reflecting practice and placebo effects. 

Post hoc comparisons revealed that older age participants in the folate treatment group identified significan

those in the placebo group. 

Post hoc comparisons reveal the that participants in the vitamin B6 and placebo groups generated significan

those in the folate and vitamin B12 treatment group. 
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Intervention and Correlation

Author, Year: Clarke, 2003 Ref ID: 41 Vitamins: B12+folat

Objective: To assess the biochemical efficacy of vitamin supplements in people at high risk of dementia Study characteristics Population Controls Inclusion criteria Exclusion criteria Definitions Study design RCT 2x2x2 

factorial design 

Age: 75 

(56-89) 

AD: 

Country: UK %Male: PD: Setting: outpatients Race: VascDz:Funding: Industry; 

government 

Other: 

Patients who believed they had memory problems; TICS-M score<27; or clinical diagnosis of dementia (DSM IV criteria) and MMSE=12-26 or on therapy for cognitive function (e.g. Donepezil, Metrifonate, Rivastigmine) for at least 3 months 

Fronto-temporal dementia; PD; Huntington’s disease; normal pressure hydrocephalus; multivitamins (unless only folate<100mg daily); life-threatening disease or cancer; concern about likely compliance; nursing home residents; peptic ulcer or aspirin sensitivity 

Other: Clin

(DSMMcogby sTIC

Comments: Age given only for total patients enrolled; AD: 84 patients; AD+VascDz: 11; VascDz: 3; cognitive impairment: 47; unkIntervention(s): Control: Total Intervention 1 InterventB12: 1mg N enrolled: 149 74 +folate: 2 mg N analyzed: 128 ND 

placebo

Drop-outs (%): 21 (14) 

Follow-up duration: 12 weeks Reasons for drop out: ND Comments: Interventions: aspirin vs. placebo; B12+folate vs. placebo; Vitamin E/C vs. placebo; N analyzed for cognitive function t

given 
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Primary outcome(s): Biochemical endpoints (homocysteine; folate; B12; isoprostane; thromboxane) Secondary outcome(s): Cognitive function scores (MMSE; ADAS-Cog; Bristol Activities of Daily Living Scale) Adverse events: ND Limitations: Sample calculation not explicitly reported and not performed for treatment efficacy on cognitive function; results for t

cognitive function not mentioned as well as N analyzed in each group; reasons for drop-outs not given. 

ND on gender; race; small sample for each dementia type. 

Quality (A/B/C): B Applicability (1/2/3): 2 Outcome(s): Results (Text) (or Definition) MMSE, ADAS-Cog, ADL Not significantly altered by treatment (specific results not shown) Unadjusted Spearman correlation coefficient between baseline cognitive function scores and baseline level of folate*, B12* 

Folate /MMSE: r=0.16, p<0.05; Folate /ADAS-Cog: r = - 0.22, p<0.01; Folate /B12 / MMSE: r= - 0.10, NS; B12/ ADAS-Cog: r= - 0.10, NS; B12/ ADL: r= 0.1

Age adjusted Spearman correlation coefficient between baseline cognitive function scores and baseline level of folate*, B12* 

Folate /MMSE: r=0.15, NS; Folate /ADAS-Cog: r = - 0.20, p<0.05; Folate /ADLB12 / MMSE: r= - 0. 05, NS; B12/ ADAS-Cog: r= 0.04, NS; B12/ ADL: r= 0.14

* B12 levels determined by a competitive protein binding immunoassay (REF 23 in the paper); folate levels by a microbioogical metho

microtiter plate method (REF 24 in the paper). No data on normal range are given for any of the methods 
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Intervention and Correlation

Author, Year: Coimbra, 2003 Ref ID: 641 Vitamins: Riboflavin 

(Riboflavi

Objective: Effect of riboflavin treatment on motor function in PD Study characteristics Population Controls 

(Correlation) 

Inclusion criteria Exclusion 

criteria 

De

Study design Prospective 

longitudinal cohort 

Age: 67.5 77.5 AD

Country: Brazil %Male: 42% 50% PDSetting: Neurology 

clinic outpatients 

Race: nd nd Va

Funding: nd Other: Hoehn & Yahr Stages: 

1, 2, 3 – 10% each; 4 – 26%; 5 – 45% 

Sporadic PD (Correlation controls: Dementia without stroke and a low Mini-Mental score) 

(Stroke, ischemic brain lesions) 

Ot

Comments: Intervention: Intervention(s): Control: Total Intervention 1 InterventRiboflavin 30 mg TID N enrolled: 31 31 (eliminate all red meat from diets) 

N analyzed: 19 19 

None 

Drop-outs (%): 39% 

Follow-up duration: 6 mo Reasons for drop out: Failure to comply for 6 mo Comments: 
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Primary outcome(s): 

Motor capacity 

Motor function scale based on expanded version of Hoehn & Yahr scale, with categories of 0 (Requires as

symptomatic drugs for PD), 14, 30, 50 (Unassisted basic care and reduced unsteadiness while on symptom(Bilateral rigidity/tremor + midline changes with normal balance prior to the early morning symptomatic dbut reduced symptoms while on symptomatic drugs for PD), 90, 95, 100 (Fully asymptomatic without sym

Secondary outcome(s): 

Reported symptoms 

Adverse events: 

nd 

Limitations: High dropout rate. Completers analysis only. No control. May be confounded by elimination of red meat from diet. Quality (A/B/C): C Applicability (1/2/3): 2 Outcome(s): Results (Text) (or Definition) Reported symptoms “About 10-15 days after beginning treatment, PD patients often reported better (progressively less interrupted) 

reasoning, higher motivation, and reduced depression. Their family members usually started noticing motor impof treatment, but in some cases of advanced disability the patient was able to change body position in bed at nigday of treatment.” 

Outcome Motor Capacity (scale 0-100%) 3 Months 

 N Riboflavin 30 mg TID N (Intervention) (Dose) N (Intervention) 

Baseline value (SE/SD) 19 44 nd Final value (SE/SD) 19 66 nd Difference (SE/SD/95% CI) P Difference <0.001 Net Difference (SE/SD/95% CI) P Net difference Outcome Motor Capacity (scale 0-100%) 6 Months 

 N Riboflavin 30 mg TID N (Intervention) (Dose) N (Intervention) 

Baseline value (SE/SD) 19 44 nd Final value (SE/SD) 19 71 nd Difference (SE/SD/95% CI) P Difference <0.001 Net Difference (SE/SD/95% CI) P Net difference 
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Correlation (Baseline) Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population oPlasma Riboflavin* ng/mL N enrolled: 41 31 Plasma Vitamin B6** ng/mL Plasma Folate*** ng/mL 

N analyzed: 41 31 

Serum Vitamin B12**** pg/mL 

PD v Dementia without stroke 

Drop-outs (%): 

Comments: * Flavin-adenin dinucleotide, HPLC/fluorometric detection, per Speek AJ 1982. ND on normal range. ** Per Sharma SK 1992. ND on normal range. *** HPLC/microbiological assay, per Kelly P 1996. ND on normal range. **** Roche Diganostics, electrochemiluminescence immunoassay. ND on normal range. Other predictors/outcomes reported: Hcy Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Quality (A/B/C): Applicability (1/2/3): Correlation of Predictors with Outcomes (Baseline) 

Plasma Riboflavin ng/mL Plasma B6 nmol/L Plasma Folate ng/mL 

Description of (Sub-) Groups Outcome N Mean SD Mean SD Mean SD 

PD 31 100.9 22.0 25.3 6.1 5.6 4.0 Dementia w/o Stroke 10 128.8 25.6 24.3 9.4 4.3 2.8 

P difference <0.01 NS NS 
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Intervention and Correlation

Author, Year: Kral, 1970 Ref ID: 1694 Vitamins: 

Objective: To determine the correlation of vit B12 and folic acid levels with the degree of memory impairment and whether pa

vit B12 would improve their memory function 

Study characteristics Population

 XS-1 RCT-2

Controls for RCT 

Inclusion criteria Exclusion criteria 

Study design XS-part 1 

CT-part2 

Age: 77 nd nd 

Country: Canada %Male: 59% 39% 55% Setting: University 

and community 

Race: nd nd nd 

Funding: Gov Other: 

Geriatric ward and homes for the aged in the Montreal area 

Subacute combined degeneratiosensory deficiencies; aphasia; thvitamins, anticonvulsants, chemblood transfusions 

Comments: Part 1 correlation: 12 without psychological or neurological symptoms; 9 senile dementia; 24 cerebral arteriosclerosis

undetermined Part 2 was Intervention: 18 formed the experimental group; 22 the control group 

Intervention(s): Control: Total Intervention 1 InterventVit B12 x 5times/wk x 14 Part 1: 63 wk 

N enrolled: 

Part 2: 40 18 

N analyzed: Part 1: 53 

Part 2: 40 18 

No treatment 

Drop-outs (%): nd 

Follow-up duration: 14 wk Reasons for drop out: nd Comments: Vit B12 <200 μmg/ml; folic acid <4 μmg/ml were considered as vitamin deficient Sr vit B12 measured by microbiological assay according to the method of Ross using Euglena gracilis Sr folic acid was determined by the method of Baker using Lactobacillus casei in a microbiological assay 
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Primary outcome(s): Part 1: correlation of vitamins with memory impairment Part 2: Comparison of change in memory 

treatment and control groups 

Secondary outcome(s): weight Adverse events: ND Limitations: Results presents as text only; 53 analyzed not randomized; but single blinded study Quality (A/B/C): C Applicability (1/2/3): 1Memory function was measured by the standard Wechsler Memory Scale. The upper and lower limit of retention span was done using 

1943) Outcome(s): Results (Text) (or Definition) 

Memory quotient The correlation study did not reveal any significant correlation between the level of serum vit B12 or folic acid 

impairment in the population as a whole. The same analysis performed separately for each sex it was found that in women the serum vit B12 level was pMQ at the 0.1 level of significance 

Treatment effect No significant change of the MQ was observed in either the vit B12 deficient subgroup, or in the subgroup with 

treatment In the subgroup with combined def, the MQ of the 2 experimental subjects increased minimally, whereas the m

experimental subjects dropped sig after the treatment 

Number of subjects MQ >100 80-100 60-80 <60 Average Sr B12 μμmg/ml 294 409 304 153 Average Sr folate μmg/ml 5.20 4.00 6.96 8.30 Ratio Folate/B12 1:56 1:100 1:42 1:1B12 to folate ratio did not correlate with MQ, but correlated positive at the 0.01 level of significance with the senile score on the age re
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Memory Quotient (0-100) 

 N Vit B12 5x/wk 7000 mg (total) 

Baseline value (ND) 18 90 Final value (ND) 18 87 Difference (ND) -3 P Difference NS Net Difference P Net difference NS Lower limit of retention span ND 

 N Vit B12 5x/wk 7000 mg (total) 

Baseline value (ND) 18 38 Final value (ND) 18 26 Difference (ND) -12 P Difference NS Net Difference P Net difference NS Upper limit of retention span ND 

 N Vit B12 5x/wk 7000 mg (total) 

Baseline value (ND) 18 48 Final value (ND) 18 42 Difference (ND) -6 P Difference NS Net Difference P Net difference NS 
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Correlation and Intervention

Author, Year: Lewerin, 2005 Ref ID: 10002 Vitamins: 

Objective: Multi-B vitamin for cognitive and movement in general population elderly 

Study characteristics Population Controls Inclusion criteria Exclusio

Study design RCT Age: 75.7 

+\-4.7 

75.6 

+\-4.0 

Country: Sweden %Male: 38% 44% Setting: Community Race: nd nd Funding: Private Other: 

Community dwelling men and women who underwent cognitive testing and Postural-Locomotor-Manual testing 

Comments: Intervention(s): Control: Total Intervention 1 Intervent

N enrolled: 195 126 N analyzed: 105-115 

Cyanocobalamin 500 μg/day 

Folate 800 μg/day 

Vit B6 HCl 3 mg/day 

Placebo 

Drop-outs (%): 

Follow-up duration: 4 mo Reasons for drop out: Illness, difficulty/pain, refusal, poor compliComments: Tests performed at different visits. Different numbers evaluated for different tests. RCT: Primary outcome(s): Cognitive and Postural-Locomotor-Manual tests Secondary outcome(s): Adverse events: nd Limitations: Quality (A/B/C): B Applicability (1/2/3): 3 
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Outcome(s): Definition Postural-Locomotor-Manual testing (movement time) Opto-electronic technique to evaluate time to lift, carry, and deposit  Simultaneity index Overlap time of different phases (sum of times of 3 individual phaseDigit span forward and backward Short term memory Identical forms Perceptual speed (time to marking identical form) Visual reproduction Visual memory (ability to remember and draw 4 forms) Synonyms Verbal ability (finding synonyms) Block design Spatial ability (reproduce design with colored blocks) Digit symbol Perceptual speed (time to replace digits with symbols by a code) Thurstone’s Picture Memory Test Long term memory (ability to remember pictures) Figure classification Inductive reasoning (ability to choose figure different from others) Baseline Correlation: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population oPlasma Folate* nmol/L Movement time N enrolled: 209 All evaluated Whole blood Folate** nmol/L Simultaneity index N analyzed: 195-207 Serum Vit B12*** pmol/L Block design (Serum MMA μmol/L) Digit symbol (Plasma Homocysteine μmol/L) 

Drop-outs (%): 

Comments: 14 subjects were excluded from RCT prior to start of RCT because of “difficulty/pain”. MMA, methylmalonic acid * Diagnostic Products Corp, Solid Phase No Boil Dualcount. Normal range: 6–35 nmol/L. ** Diagnostic Products Corp, Solid Phase No Boil Dualcount. Normal range: 100–450 nmol/L. *** Diagnostic Products Corp, Solid Phase No Boil Dualcount. Normal range: 130–750 pmol /L. Correlation of Predictors with Outcomes (Baseline): Multivariate analysis* 

Plasma Folate nmol/L Whole blood Folate nmol/L Serum B1

Description of (Sub-) Groups 

N 

Mean SD β R2 P Mean SD β R2 P Mean SD 

All: Block Design (WAIS) 207 16.0 6.61 +0.029 0.13 NS 351 134.9 -0031 0.13 NS 325 159
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All: Digit Symbol (WAIS) 204 +0.083 0.10 NS -0.004 0.10 NS β, Regression coefficient * Adjusted for age, sex, smoking, serum creatinine 
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Digit Span Forward (WAIS) (0-9) 

 N B vitamins 

Baseline value (SD) 115 5.8 1.1 Final value 115 Difference (SEM) +0.24 0.09 P Difference Net Difference P Net difference NS Digit Span Backward (WAIS) (0-8) 

 N B vitamins 

Baseline value (SD) 115 4.4 1.2 Final value 115 Difference (SEM) +0.25 0.09 P Difference Net Difference P Net difference NS Identical Forms (0-60) 

 N B vitamins N 

Baseline value (SD) 115 23.3 7.6 61 Final value 115 61 Difference (SEM) +0.13 0.37 +1.P Difference Net Difference P Net difference 0.04* * Note placebo better than B vitamins 
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Visual Reproduction (0-14) 

 N B vitamins 

Baseline value (SD) 113 6.9 3.1 Final value 113 Difference (SEM) +0.61 0.23 P Difference Net Difference P Net difference NS Synonyms (0-30) 

 N B vitamins 

Baseline value (SD) 110 22.5 4.7 61 Final value 110 61 Difference (SEM) +0.31 0.25 +1P Difference Net Difference P Net difference 0.02* * Note placebo better than B vitamins Block Design (WAIS) (0-42) 

 N B vitamins 

Baseline value (SD) 114 18.5 6.3 6Final value 114 6Difference (SEM) +0.99 0.37 +P Difference Net Difference P Net difference NS 
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Digit Symbol (WAIS) (0-90) 

 N B vitamins 

Baseline value (SD) 113 35.1 10.0 62 Final value 113 62 Difference (SEM) +0.95 0.52 +P Difference Net Difference P Net difference 0.09* * Note placebo better than B vitamins Thurstone’s Picture Memory Test (0-28) 

 N B vitamins 

Baseline value (SD) 115 20.3 4.8 Final value 115 Difference (SEM) +1.75 0.30 P Difference Net Difference P Net difference NS Figure Classification (0-30) 

 N B vitamins 

Baseline value (SD) 113 15.8 4.8 6Final value 113 6Difference (SEM) +1.45 0.33 +P Difference Net Difference P Net difference NS Neither basal Hcy, MMA, B12, folate showed associations with change in cognitive performance. 
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Intervention and Correlation

Author, Year: Mitsuyama, 1988 Ref ID: 2185 Vitamins: 

Objective: To examine the effect of CH3-B12 on the CNS and clinical effectiveness for organic mental symptoms. To determin

the serum vitB12 and CSF vitB12 

Study characteristics Population Controls Inclusion criteria Exclusion criteria Study design Non 

comparative open trial and correlational study 

Age: 53±3.1 

(34-77) 

Country: Japan %Male: 64% Setting: Academic 

hospital 

Race: 100% 

Asian 

Funding: ND Other: 

Subjects who fulfilled the clinical criteria of dementia. Confirmed in all patients by the finding of cerebral atrophy and widening of the ventricles on the CT scan. 

Any disorder known to affect vit B12 metabolism, such as acute physical disease, malnutrition, severe anemia, and myeloproliferative disorders and abnormal kidney and liver disorders 

Comments: 4 patients were mildly demented; 7 moderately demented; 3 patients were severely demented 

Intervention(s): Control: Total Intervention 1 Intervent

Vit B12 2mg/d for 60d N enrolled: 14 5 9 Vit B12 2 mg/d PO and 500μg/d IM 

N analyzed: 14 5 9 

None 

Drop-outs (%): 0 

Follow-up duration: 60 days Reasons for drop out: NA Comments: Sr and CSF B12 assessed by radioassay range between 25 to 1600 pg/mL 
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Primary outcome(s): Change in GBS scale (a neuropsychological scale developed by Gottfries) Correlation between sSecondary outcome(s): Correlation of sr and CSF-VB 12 with severity of dementia Adverse events: ND Limitations: Small sample size ( only 1 patient with AD and W-K); 1 patient had unclassified presenile dementia; a

disease 

Quality (A/B/C): B (comparative trial and small sample size) Applicability (1/2/3): 2 Broad range of dOutcome(s): Results (Text) (or Definition) Correlation of Serum and CSF Vit B12 with severity of dementia 

No correlation between the concentration of serum and CSF vit B12 levels and severity of dementia w

Change in GBS scale No change in GBS scale with administration of CH3-B12. However patients on both PO and IM repo

mood and social behavioral changes and enhanced self rating of competencies 
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Intervention and Correlation

Author, Year: Shaw Ref ID: 2954 Vitamins: 

Objective: Effect of B12/Folate on cognitive function in patients with AD and low folate 

Study characteristics Population Controls Inclusion criteria Exclusion criteria 

Study design Randomized 

Xover 

Age: 80.6+/-

6.7 

Country: UK %Male: nd Setting: In-patients Race: nd Funding: nd Other: 

In-patients diagnosed with senile dementia. RBC folate <130 ng/mL 

Serious impairment of cardiapulmonary or renal function. arteriosclerosis 

Comments: Double blind. No washout. Intervention(s): Control: Total Intervention 1 Interven

N enrolled: 66 66 N analyzed: 17 17 (10 first arm) 

Hydroxycobalamin 1000 μg IM x 7 days, then weekly Folate 15 mg po daily 

Placebos 

Drop-outs (%): 74% 

Follow-up duration: 12 wk Reasons for drop out: “Patients selected were severely demen

difficulty in cooperating sufficiently” o

Comments: Primary outcome(s): Psychometry (see tests below) Secondary outcome(s): Folate, B12, other levels Adverse events: nd Limitations: Inappropriate tests used for such severely demented group. Thus 3⁄4 dropouts. Data incomplete. Quality (A/B/C): C Applicability (1/2/3): 1 Outcome(s): Definition Synonym Learning Test Digit Copying Score Kendrick 1967 Dementia Scale (without Changes in Personality) Information-Memory-Concentration Test Blessed 1968 Intervention

The means for the Dementia Scales were unchanged in both groups. Those for The Information-Memory-Concentration scores rose slig

was not statistically significant. 
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Correlation

Author, Year: Andersen-Ranberg, 2001 Ref ID: 119 Vitamins: B12, Fola

Objective: Relation of dementia to other diseases Study characteristics Population Inclusion criteria Exclusion criteria Definitions 

XS Age: 100 Cases: Cases: Comparative %Male: 22% 

Study design AD: 

Prospective Race: nd 

All individuals in Denmark turning 100 y.o. between 4/1/95 and 5/31/96. 

Refused (n=56). Died within weeks of birthday, prior to contact (n=13). Missing data (n=11). 

PD: 

Country: Denmark Other: Controls: Controls: VascDz: Setting: Population Funding: Government 

Dementia: WH

SevDemHug

Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population of “B12 or Folate deficiency” nd Demented ICD-10 N eligible: 276 

N analyzed: 196 105 Drop-outs (%): 

Comments: Other predictors/outcomes reported: CVD, DM, Hypothyroid, PD Follow-up duration (if applicable): Reasons for drop out (if applicable): See Exclusion criteria Limitations: Limited details or analyses. Centenarians only. Quality (A/B/C): C Applicability (1/2/3): 
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Correlation of Predictors with Outcomes (cross-sectional studies) 

Serum B12 or Folate deficiency (nd) p 

Description of (Sub-) Groups N n % 

Demented 105 9 9% nd Non-demented 91 10 11% 
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Correlation

Author, Year: Anello, 2004 Ref ID: 123 Vitamins: Folate, B1

Objective: MTHFR polymorphisms and AD Study characteristics Population Controls Inclusion criteria Exclusion 

criteria 

XS Age: 71.0+/-

6.6 

69.5+/-

12.7 

Cases: Cases: 

Comparative %Male: nd nd 

Study design 

Prospective Race: nd nd 

Ambulatory, AD 

Country: Italy Raiseberg score 

>6: 

30% Controls: Controls: 

Setting: Clinic Early onset (<65 y) 

AD: 

23% 

Funding: nd 

Ambulatory, from same geographical area 

AD 

Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population Vitamin B12* pmol/L AD Diagnosis N enrolled: 361 18Folates* nmol/L Dementia severity Reisberg scale (1982) Homocysteine μmol/L Age of AD onset Early: <65 y ApoE ε4 

N analyzed: 361 18

MTHFR Drop-outs (%): Comments: * Abbott IMX automated Benchtop analyzer system, Microparticle enzyme immunoassay (MEIA). No data on normal range. Other predictors/outcomes reported: Transcobalamin gene (TCN1) Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Quality (A/B/C): B Applicability (1/2/3): 
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Correlation of Predictors with Outcomes (cross-sectional studies) 

Plasma B12 pmol/L p Plasma Folates nmol/L p (Sr/CSF) (B vit) (unit) (Sr/

Description of (Sub-) Groups 

N 

Mean SD Mean SD Mean SE/SD r= Me

AD 180 278 221 NS 14.3 5.7 0.09 Controls 181 283 211 15.7 5.9 

Diagnosis of AD 

Logistic Regression Predictors: 

N 

OR (Unadjusted) P (univariate) P (multivariate*)

Folate 0.95 (0.91, 1.00) 0.04 NS (0.2) Vitamin B12 361 1.00 (0.99, 1.01) NS NS * Adjusted for MTHFR, ApoE ε4, and TCN1 genotypes, and homocysteine level (and other B vitamin) Outcome(s): Results (Text) Severity of dementia (Reisberg scale) 

“Plasma levels of (Hcy,) folate and vitamin B12 were not influenced by the severity of dementia or age of onse
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Correlation

Author, Year: Argyriadou, 2001 Ref ID: 144 Vitamins: B12, Fola

Objective: Association between cognitive impairment and anemia Study characteristics Population Inclusion criteria Exclusion criteria Definit

XS Age: 65-74: 50% 

75-84: 35% 85+: 15% 

Cases: 

Non-comparative %Male: 46% 

Study design AD: 

Prospective Race: nd 

Cases: Age ≥65 y 

a. living in geriatric facility (n=48), b. visit geriatric community center (n=75), c. received routine care at health center (n=413)

PD: 

Country: Greece Other: Controls: Controls: VascDzSetting: Community Funding: nd (report no conflicting interests) 

Possibimpairm

Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total PopulatioVitamin B12 (normal v abnormal)* Abnl: <145 pg/mL MMSE N enrolled: 5Folate (normal v abnormal)* Abnl: <1.8 ng/mL N analyzed: 5

Drop-outs (%): 

Comments: * Micro Merieux analyzer, ELISA. ** Imx automatic analyzer, Ion Capture Immune Assay (ICIA). Other predictors/outcomes reported: Hematocrit, Age Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Limited analyses. Potentially biased sample due to eligibility criteria Quality (A/B/C): C Applicability (1/2/3): Outcome(s): Results (Text) 
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Correlation of Predictors with Outcomes (cross-sectional studies) 

p N p N 

Description of (Sub-) Groups 

N 

(Total) % (Men) % (Women) 

Normal B12 (≥145 pg/mL) MMSE ≤24 480 37.9% 221 34.8% 259 MMSE >24 62.1% 65.2% Low B12 (<145 pg/mL) MMSE ≤24 56 55.4% nd 24 62.5% 0.008 32 MMSE >24 44.6% 37.5% Normal Folate (≥1.8 ng/mL) MMSE ≤24 521 39.5% 239 37.7% 282 MMSE >24 60.3% 62.3% Low Folate (<1.8 ng/mL) MMSE ≤24 15 46.7% NS 6 33.3% 9 MMSE >24 53.3% 66.7% 66.7% 

MMSE ≤24 

Logistic Regression Predictors: 

N 

OR (Adjusted*) P (multivariate)

Low B12 (<145 pg/mL) 2.0 (1.1, 4.0) 0.03 Low Folate (<1.8 ng/mL) 536 3.8 (0.9, 15.2) 0.06 * Adjusted for age, intake site, and presence of anemia (and other B vitamin) 
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Correlation

Author, Year: Assantachai, 1997 Ref ID: 157 Vitamins: B1, B12, F

Objective: Association of B1, B12, and folate deficiency and cognitive impairment Study characteristics Population Inclusion criteria Exclusion 

criteria 

Defi

XS Age: 69.3 (60-87) Cases: Cases: Non-comparative %Male: 39% 

Study design AD: 

Prospective Race: Thai 

Enrolled in geriatric day centers, independently living, “well living”. PD: 

Country: Thailand TMSE: 27.38 (2.02) Controls: Controls: VascSetting: Community 

(rural) 

Cognimpa

Funding: nd Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total PThiamin pyrophosphate effect (normal: 0-15%)* 

% N enrolled: 

Vitamin B12** pg/mL N analyzed: RBC Folate*** ng/mL 

Thai Mental State Examination (TMSE)* 

6 categories (orientation, registration, attention, calculation, language, abstract thinking, recall) Maximum 30 Drop-outs 

(%): 

Comments: * Spectrophotometry. No data on normal range. ** Radiodiolution assay (Co57). No data on normal range. 

*** Microbioassay using lactobacillus casei ATCC 7469 and spectrophotometry. No data on normal range. Other predictors/outcomes reported: 

Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Quality (A/B/C): B Applicability (1/2/3): 
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Correlation of Predictors with Outcomes (cross-sectional studies) Description of Serum B1 effect (%) Serum B12 (pg/mL) RBC (Sub-) Groups N Mean SD P N Mean SD P N Cognitively impaired (TMSE<24) 63 12.44 8.81 NS 51 460 488 NS 44 Normal (TMSE≥24) 138 10.90 7.68 108 408 184 103 
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Correlation

Author, Year: Bernard, 1998 Ref ID: 269 Vitamins: B12 

Objective: Association of B12 (different measurements) and cognitive impairment Study characteristics Population Inclusion criteria Exclus

criteria 

XS Age: 71.5 (65-89) Cases: Cases: Non-comparative %Male: 99% 

Study design 

Prospective Race: White* 

Black Other 

88% 

9% 3% 

Ambulatory veterans, age≥65 y, who came to 

outpatient laboratory 

Country: US Other: Controls: ControSetting: Community 

(VA) 

Funding: Government Comments: * Non-Hispanic Predictor(s): (eg, B vit level) Outcome(s): Definition: Total PoB12 deficiency 

< laboratory norm (200 pg/mL)* MMSE N enrolled: 

B12 N analyzed: deficiency 

< laboratory norm (200 pg/mL)* or >200 & <300 pg/mL & either MMA >2 SD above normal (271) or Hcy >2 SD above normal (16) 

Drop-outs (%): 

Comments: * No data on measurement method. Other predictors/outcomes reported: RAND 36-Item Health Survey Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Quality (A/B/C): B Applicability (1/2/3): 
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Correlation of Predictors with Outcomes (cross-sectional studies) 

MMSE (0-30) p BDS 

Description of (Sub-) Groups 

N 

Mean* SD Mean 

B12 <200 pg/mL 19 22.54 1.89 <0.05 4.19 B12 ≥200 pg/mL 284 27.21 2.02 4.07  4.17 B12 deficient (broad)** 49 26.78 2.04 NS (0.15) 4.00 B12 normal (broad) 254 27.25 2.01 *Least Squares mean (adjusted for alcohol intake (yes/no), vitamin use, annual income (dichotomous at $10,000), level of education. 

** < laboratory norm (200 pg/mL) or (>200 & <300 pg/mL & either MMA >271 or Hcy >16) 
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Correlation

Author, Year: Bowirrat, 2002 Ref ID: 395 Vitamins: B12, Fola

Objective: Evaluation of dissociation between AD and ApoE ε4 in population of Arabs Study characteristics 

Population Inclusion criteria Exclusion criteria 

Longitudinal Age: Cases: Cases: Non-comparative %Male:

Study design 

Prospective Race: Arab 

Age ≥60 y, resident in 3 Arab villages in 

northern Israel 

Refused to participate (n=12) 

Country: Israel Other: Controls: Controls: Setting: Community 

(rural) 

Funding: Government, Private non-profit, 

Industry 

Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population Plasma B12* Dementia of the Alzheimer type (DAT) DSM-IV N surveyed: 823 Plasma Folate* Incident (new onset) DAT N analyzed: 234 7Comments: * No data on methodology used or normal range. Other predictors/outcomes reported: ApoE ε4, age, concomitant medical conditions, smoking Follow-up duration (if applicable): Mean 20+/-4 (up to 23.4) months Reasons for drop out (if applicable): Labwork drawn only from 234/823 subjects Limitations: No results data reported, “perhaps the lowest ApoE ε4 frequency reported in the world: 3.5Quality (A/B/C): C Applicability (1/2/3): Outcome(s): Results (Text) Baseline AD prevalence 

Plasma B12 and plasma folate levels did not differ significantly between AD patients and controls after adjustin

AD incidence Subjects (in the highest Hcy tertile or) in the lowest B12 and folate tertile did not have greater risk to develop A

year of birth and gender. 
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Correlation

Author, Year: Bunce, 2004 Ref ID: 444 Vitamins: B12, Folat

Objective: Association of ApoE ε4 and B12/Folate with cognitive impairment 

Study characteristics Population Inclusion 

criteria 

Exclusion criteria 

XS Age: 82.8 (5.7) Cases: Cases: Non-comparative %Male: 20% 

Study design 

Prospective Race: nd 

Age ≥75 y, Dementia, depression, incomplete laboratory data, B12 

folate supplementation, “abnormally high” folate level

Country: Sweden Other: Controls: Controls: Setting: Community Funding: Government, Private non-profit Comments: 

Predictor(s): (eg, B vit level) 

Outcome(s): 

Serum B12* pmol/L Free recall of sematically 

unrelated words 

2 lists of 12 concrete nouns, presented slowly or rapidly, immediate recall 

N potential from survey: 

Serum Folate* nmol/L Free and cued recall of 

organizable words 

23 nouns belonging to categories, presented slowly 

N analyzed: 

ApoE genotype Comments: * Radioimmunoassay. No data on normal range. Other predictors/outcomes reported Follow-up duration (if applicable): Reasons for drop out (if applicable): See Exclusions Limitations: Multiple exclusions and missing data Quality (A/B/C): B Applicability (1/2/3): 2 

* Multiple detailed ANOVA and ANCOVA results were reported. 
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Correlation

Author, Year: Bunce, 2005 Ref ID: 445 Vitamins: B12, Folat

Objective: Association of B vitamin with cognition, correlation with ApoE genotype Study characteristics Population Inclusion 

criteria 

Exclusion criteria 

XS Age: 82.8 Cases: Cases: Non-comparative %Male: 20% 

Study design 

Prospective Race: ~100% 

white 

≥75 y Dementia, clinical depression, incomplete B12 

or folate data, B12 or folate supplement, abnormally high folate, ApoE data unavailable 

Country: Sweden Other: 8.9 yr 

education 

 

Setting: Community Funding: Private and Government Comments: Excluded people with dementia Predictor(s): (eg, B vit level) 

Outcome(s): Total Population of i

Serum B12* Low: <251 

pmol/L 

Face recognition: 

20 famous faces from 1930-1950 & 20 contemporary 1980s 

N enrolled: 167 Non-dement

Serum Folate* 

Low: <13 nmol/L 

Short term memory 

WAIS-R forward and backward digit span (FDS, BDS) 

N analyzed: 

167 

ApoE genotype 

ε4 vs non-ε4 Visuospatial 

ability 

WAIS-R Block design test, Clock setting and reading ability 

Drop-outs (%): 

(361 did not meet criteria, inclu

data and 32 with eleva

Comments: * Radioimmunoassay Other predictors/outcomes reported none Follow-up duration (if applicable): NA Reasons for drop out (if applicable): NA Limitations: Excluded people with dementia, Did not analyze B vitamins as continuous variables. Quality (A/B/C): B Applicability (1/2/3): 3 
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Outcome(s): Results (Text) Recognition of contemporary and dated famous faces B12 and ApoE 

Low B12 (<251 pmol/L) significantly associated with poorer face recognition sTwo-way interaction of B12 and ApoE (ε4 vs non-ε4) non-significant 

Visuospatial skills B12 and ApoE 

No significant associations for Clock reading, or Clock drawing 

Recognition of contemporary and dated famous faces Folate and ApoE 

Low Folate (<13 nmol/L) significantly associated with poorer face recognition Two-way interaction of Folate and ApoE (ε4 vs non-ε4) non-significant 

Visuospatial skills Folate and ApoE 

No significant associations for Clock reading, or Clock drawing 

Correlation of Predictors with Outcomes (cross-sectional studies) 

FDS (0-9) p BDS (0-9) p Block Design (0-4

Description of (Sub-) Groups 

N 

Mean SD Mean SD Mean SD 

ApoE ε4 Normal B12 21 5.52 1.29 4.19 1.03 13.95 4.53 ApoE ε4 Low B12 (<251 pmol/L) 28 5.36 0.91 4.07 0.94 12.32 4.30 ApoE non-ε4 Normal B12 64 5.83 1.15 4.17 1.11 14.95 5.55 ApoE non-ε4 Low B12 (<251 pmol/L) 54 5.26 1.09 

NS* 

4.00 1.06 

NS* 

11.33 5.72 

ApoE ε4 Normal Folate 34 5.47 1.21 4.00 0.92 13.56 3.83 ApoE ε4 Low Folate (<13 nmol/L) 15 5.33 0.72 4.40 1.06 11.80 5.5ApoE non-ε4 Normal Folate 88 5.57 1.10 4.15 1.07 13.56 5.88 ApoE non-ε4 Low Folate (<13 nmol/L) 30 5.57 1.10 

NS* 

3.93 1.14 

NS* 

12.79 5.93 

FDS, WAIS-R forward digit span; BDS, WAIS-R backward digit span; * NS by ANCOVA adjusted for age, years of education, gender, stroke, coronary heart disease, other heart disease and diabetes, and ce
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Correlation

Author, Year: Cacabelos, 2004 Ref ID: 477 Vitamins: B12, Fola

Objective: Comparison of AD and vascular dementia Study characteristics Population Controls Inclusion criteria Exclusion 

criteria 

Definitions 

XS Age: 71 70 Cases: Cases: Comparative %Male: 36% 45% 

AD: 

Study design 

Prospective Race: nd nd 

Diagnosed with AD by conventional criteria. MMSE<24 and Hachinski<6 

PD: 

Country: Spain Other: Controls: Controls: Vascular 

dementia 

Setting: nd Funding: nd 

Diagnosed with dementia with vascular component, including vascular dementia, mixed dementia, and patients with cerebrovascular disorders, MMSE<24, Hachinski>6 

Cerebrovascular disorders: 

Comments: Source of subjects unclear Predictor(s): (eg, B vit level) Outcome(s): Definition: Total PopulatioFolate (blood)* ng/mL Dx AD N enrolled: Vitamin B12 (blood)** pg/mL N analyzed: 939 Interaction with ApoE genotype 2/3 v 2/4 v 3/3 v 3/4 v 4/4 Drop-outs (%): Comments: * No data on measurement technique. Folate deficiency defined as folate < 3.0 ng/mL. ** No data on measurement technique. B12 deficiency defined as B12 < 150 pg/mL. Other predictors/outcomes reported: 107 laboratory, radiographic, history, physical examination variables, genomFollow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: No correction for multiple testing or adjustments madeQuality (A/B/C): B Applicability (1/2/3): (no data on source of sample) 
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Outcome(s): Results (Text) Folate interaction with ApoE genotype 

No significant difference in folate levels between patients with AD and specific ApoE genotypes and their coun

dementia. 

B12 interaction with ApoE genotype 

Patients with AD and ApoE 2/4 (n=4 or 6) had significantly lower B12 level (364+/-141 pg/mL) than patients w

ApoE 2/4 (n=9; 678+/-365 pg/mL; P<0.04). AD patients with other genotypes had similar B12 levels as their c

dementia. 

Correlation of Predictors with Outcomes (cross-sectional studies) 

Blood Folate ng/mL p Blood B12 pg/mL p 

Description of (Sub-) Groups 

N 

Mean SD Deficiency* Mean SD Deficiency** 

AD 465 6.10 2.81 5% NS (mean) 487.95 327.83 4% NS (mean) Vascular dementia 474 6.31 3.13 6% 520.98 504.80 3% * < 3.0 ng/mL ** <150 pg/mL 
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Correlation

Author, Year: Clarke, 1998 Ref ID: 622 Vitamins: Folate, B1

Objective: Hcy (Folate, B12, MTHFR) and AD Study characteristics Population Controls Inclusion criteria Exclus

n crite

XS (with All Autopsy autopsy in some) Longitudinal 

Age*: 73.2+/-

8.6 

76.6+/-

8.0 

72.8+/-

8.8 

Comparative %Male: 39% 37% 43% 

Study design 

Retrospective Race: nd nd nd 

Cases: Cognitive dysfunction, referred to Oxford Project to Investigate Memory and Ageing. Histologically confirmed at autopsy (n=76) or clinical diagnosis of probable or possible AD (n=88)

Cases: Age <55 y, no blood sample availabl

Country: UK CAMCOG: 55.2 45.1 97.8 Controls: ControSetting: Clinic MMSE 16.2 12.8 28.5 Funding: Pharmaceutical 

Elderly volunteer controls without symptoms of memory impairment (17 of whom were patients’ relatives) 

Comments: Subset of subjects analyzed by Refsum 2003 Ref ID 2661 * Age at time of laboratory testing, regardless of when diagnosis made (ie, autopsy) CAMCOG, Cambridge Cognitive Examination, maximum score 107 MMSE, Mini-Mental Status Examination, maximum score 30 Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population Serum Folate* nmol/L AD vs non-AD N enrolled: 272 1RBC Folate* nmol/L Medial temporal lobe CT Serum B12** pmol/L (Serum Hcy μmol/L) (ApoE ε4 allele frequency) 

N analyzed: 272 1

(MTHFR homozygous mutant frequency) Drop-outs (%): Comments: * Microbiological assay. No data on normal range. ** Radioimmunoassay. No data on normal range. Other predictors/outcomes reported: Follow-up duration (if applicable): XS and 4 years Reasons for drop out (if applicable): 
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Limitations: Quality (A/B/C): B Applicability (1/2/3): 2 Correlation of Predictors with Outcomes (cross-sectional studies) 

Serum Folate nmol/L p RBC Folate nmol/L p Serum B12 Pm

Description of (Sub-) Groups 

N 

Mean SD r= Mean SD r= Mean SD 

AD (all) 164 17.6 10.7 <0.001 866 446 <0.05 236 112 AD (subset w/histology) 76 15.2 9.5 <0.001 737 386 <0.001 215 79 Healthy controls 108 22.9 10.0 -- 991 407 -- 253 100 

Clinically Diagnosed AD N Histologic

Description of (Sub-) Groups 

N 

OR (Adj 1*) OR (Adj 2*) OR (Adj 1*) 

 Serum Folate >24.2 nmol/L 1 1 1  Serum Folate 17.2-24.2 nmol/L 0.8 (0.5-1.4) 0.7 (0.4-1.5) 0.6 (0.2-1 Serum Folate <17.2 nmol/L 

272 

2.5 (1.7-3.8) 2.3 (1.4-3.8) 

184 

5.0 (3.1-8

 Serum B12 >280 pmol/L 1 1 1  Serum B12 200-280 pmol/L 1.3 (0.8-2.0) 1.7 (1.0-3.0) 2.1 (1.2-3 Serum B12 <200 pmol/L 

272 

1.4 (0.9-2.2) 1.4 (0.8-2.5) 

184 

1.8 (1.0-3

 Serum Folate <17.2 nmol/L  Serum B12 <200 pmol/L * Adj 1, adjusted for age and sex; Adj 2, adjusted for age, sex, smoking, social class, and ApoE ε4. 

** Addition of Hcy to multivariate model 
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C-136 

Outcome(s): Results (Text) AD Diagnosis 60% of patients with DAT and 76% with histologically confirmed AD 

concentrations in the bottom 1/3 of the control distribution 

Longitudinal CT scan of age-corrected minimum thickness of the Medial Temporal Lobes (annual x 4 yr) 

Non-significant trend toward association between both serum folate adisease progression, as assessed by thinning medial temporal lobes 
Appendix C. Evidence Tables 

B Vitamin Evidence Table - Human studies 

C-137 

Correlation

Author, Year: Crystal, 1994 Ref ID: 695 Vitamins: B12 

Objective: Longitudinal association between low B12 and cognitive dysfunction Study characteristics Population Inclusion criteria Exclusion 

criteria 

Defin

Longitudinal Age: (75-85) Cases: Cases: Non-comparative %Male: nd 

AD: 

Study design 

Prospective Race: nd 

Age 75-85 y, residing in the community, healthy, cognitively intact. PD: 

Country: US Other: Controls: Controls: VascSetting: Community OtherFunding: Government Comments: Predictor(s): (eg, B vit level) 

Outcome(s): Definition: Total 

Serum Vitamin B12* pg/mL Fuld Object Memory Evaluation (FOME) test of recent 

memory 

N enrolled: 

 Blessed Test of Information, Memory and 

Concentration (BIMC) 

N analyzed: Drop-outs (%): 

Comments: * Corning RIA: Normal geometric mean 458 (95% CI 171, 953) pg/mL Other predictors/outcomes reported: Follow-up duration (if applicable): 5 years Reasons for drop out (if applicable): Limitations: Incomplete description of study sample, tests, or results Quality (A/B/C): C Applicability (1/2/3): Outcome(s): Results (Text) 
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C-138 

Correlation of Predictors with Outcomes (Baseline) 

FOME (nd) p BIMC (nd) p 

Description of (Sub-) Groups 

N 

Mean r= Mean r= 

Serum Vit B12 <150 pg/mL 22 7.10 2.23 Serum Vit B12 >150 pg/mL 388 7.40 0.01 NS 2.46 -0.03 NS Correlation of Predictors with Outcomes (At time of diagnosis of AD vs. Baseline all) 

Serum B12 pg/mL p 

Description of (Sub-) Groups 

N 

Mean 

AD (time of diagnosis) 19 551 Cognitively intact (baseline, all subjects) 410 558 NS Correlation of Predictors with Outcomes (Longitudinal) 

AD** p All Dementia** p 

Description of (Sub-) Groups 

N 

n % n % 

Serum Vit B12 <150 pg/mL (baseline)* 22 3 4.5% 1 13.6% Serum Vit B12 >150 pg/mL (baseline) 388 29 7.5% NS 57 14.7% NS * Treated by private physicians for B12 deficiency. ** Incidence over 5 years. 
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Correlation

Author, Year: Duthie, 2002 Ref ID: 10003 Vitamins: Folate and 

Objective: The potential contributions of blood Vit B12, folate, and Hcy concentrations to individual differences in life cognitive 

childhood IQ into account 

Study characteristics Population ABC 

21

ABC 36 Inclusion criteria Exclusion 

criteria 

D

XS/Longitudinal Age: 77 62 Cases: Cases: Comparative %Male: 50% ND 

Study design AD

Retrospective Race: Probably 

white 

Probably 

white 

Invited to participate the 2 cohorts of survivors of Aberdeen 1921 Birth cohort and Aberdeen 1936 Birth cohort in 2 assessments during the years 1998-1999(wave 1) and the second in 1999-2000 (wave 2) 

Blood b12 conc was 664 pmol/L and blood folate >59nmol/L 

PD

Country: UK Other: Controls: Controls: VaSetting: Academic 

setting 

OD

Funding: Private non industry and Gov Comments: 2 cohorts with different birth yrs ie survivors of Aberdeen 1921 Birth cohort and Aberdeen 1936 Birth cohort were used for 

Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population of intVit B12 pmol/L MMSE <24 suggestive of mild dementia 

<20 indicate dementia 

N enrolled: 335 186 

Folate nmol/L N analyzed: 309 165 

Drop-outs (%): 1% 

Comments: Plasma and RBC folate and vit B12 were measured using Simultrac Radioassay kit vit B12 57Co/folic acid 125I 
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C-140 

Other predictors/outcomes reported: 

Predictors: National adult reading test (NART); Ravens progressive matrices (RPM); Auditory ve(AVLT); Block design (BD); Digital symbol subtest (DS) Outcomes: Homocysteine 

Follow-up duration (if applicable): 

ND 

Reasons for drop out (if applicable): 

3 patients were removed from the analysis because their blood level for vitamins met the exclusio

Limitations: Quality (A/B/C): B Applicability (1/2/3): Correlation of Predictors with Outcomes (cross-sectional studies) (MMSE vs vit) 

Sr B 12 pmol/L p Pl Folate nmol/L p RBC Folate μg/g protein Description p (S

of (Sub-) Groups 

N 

Mean CI r= Mean CI r= Mean CI r= M

ABC21 165 280.0 263.5, 296.1 0.24 <0.01 16.8 15.6, 17.9 0.20 <0.05 1.04 0.98, 1.1 0.13 NS ABC36 144 291.5 275.9, 296.1 0.03 NS 17.7 16.3, 19.0 0.0 NS 0.98 0.92, 1.04 -0.03 NS Correlation of Predictors with Outcomes (cross-sectional studies)* (MMSE vs vit) 

Sr B 12 pmol/L p Pl Folate nmol/L p RBC Folate μg/g protein Description p (S

of (Sub-) Groups 

N 

Mean CI r= Mean CI r= Mean CI r= M

ABC21 165 280.0 263.5, 296.1 +0.23 <0.01 16.8 15.6, 17.9 0.19 <0.05 1.04 0.98, 1.1 0.09 NS ABC36 144 291.5 275.9, 296.1 +0.05 NS 17.7 16.3, 19.0 0.02 NS 0.98 0.92, 1.04 -0.046 NS * adjusted for childhood intelligence quotient 
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C-141 

Correlation of Predictors with Outcomes (cross-sectional studies) (BD vs vit) 

Sr B 12 pmol/L p Pl Folate nmol/L p RBC Folate μg/g protein Description p (S

of (Sub-) Groups 

N 

Mean CI r= Mean CI r= Mean CI r= M

ABC21 165 280.0 263.5, 296.1 -0.06 NS 16.8 15.6, 17.9 +0.06 NS 1.04 0.98, 1.1 0.02 NS ABC36 144 291.5 275.9, 296.1 +0.03 NS 17.7 16.3, 19.0 0.24 <0.05 0.98 0.92, 1.04 0.08 NS Correlation of Predictors with Outcomes (cross-sectional studies)* (BD vs vit) 

Sr B 12 pmol/L p Pl Folate nmol/L p RBC Folate μg/g protein Description p (S

of (Sub-) Groups 

N 

Mean CI r= Mean CI r= Mean CI r= M

ABC21 165 280.0 263.5, 296.1 -0.07 NS 16.8 15.6, 17.9 0.07 NS 1.04 0.98, 1.1 0.01 NS ABC36 144 291.5 275.9, 296.1 0.097 NS 17.7 16.3, 19.0 0.24 <0.01 0.98 0.92, 1.04 0.19 NS * adjusted for childhood intelligence quotient Correlation of Predictors with Outcomes (cross-sectional studies) (DS vs vit) 

Sr B 12 pmol/L p Pl Folate nmol/L p RBC Folate μg/g protein Description p (S

of (Sub-) Groups 

N 

Mean CI r= Mean CI r= Mean CI r= M

ABC21 165 280.0 263.5, 296.1 0.03 NS 16.8 15.6, 17.9 0.19 <0.05 1.04 0.98, 1.1 0.19 <0.05 ABC36 144 291.5 275.9, 296.1 0.10 NS 17.7 16.3, 19.0 0.14 NS 0.98 0.92, 1.04 0.08 NS Correlation of Predictors with Outcomes (cross-sectional studies)* (DS vs vit) 
Appendix C. Evidence Tables 

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C-142 

Sr B 12 pmol/L p Pl Folate nmol/L p RBC Folate μg/g protein Description p (S

of (Sub-) Groups 

N 

Mean CI r= Mean CI r= Mean CI r= M

ABC21 165 280.0 263.5, 296.1 -0.03 NS 16.8 15.6, 17.9 0.19 <0.05 1.04 0.98, 1.1 0.09 NS ABC36 144 291.5 275.9, 296.1 0.159 NS 17.7 16.3, 19.0 0.111 NS 0.98 0.92, 1.04 0.03 NS * adjusted for childhood intelligence quotient
Appendix C. Evidence Tables 

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C-143 

Correlation

Author, Year: Engelborghs, 2004 Ref ID: 918 Vitamins: B12, folat

Objective: To test for possible correlations of decreased sr vit B12 and red cell folate levels with degree of cognitive impairment 

and psychological signs and symptoms of dementia among AD and FTD patients 

Study characteristics Population Inclusion criteria Exclusion criteria Defi

XS Age: 79±7 69±11 Cases: Cases: Comparative %Male: 48% 50% 

AD: 

Study design 

Prospective Race: ND ND 

Consecutively hospitalized patients for diagnostic work up of dementia 

Patients on vitamin supplementation, alcohol abuse, and artificially fed PD: 

Country: Belgium Other:Disease 

duration 

4±3 6±4 

P=<0.001 

Controls: Controls: Vasc

Setting: Academic 

hospital 

MMSE score 12.7±6.9 16.3±8.3 

P=0.02 

OtheFTD 

Funding: University and private non-industry 

Same as above Same as above 

Comments: Staging of dementia done on global deterioration scale Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population of inteSr vit B12 193-982 pg/mL Hierarchic Dementia scale 0-10 N enrolled: 180 152 Red cell folate 93-641 ng/mL MMSE 0-30 N analyzed: 180 152 

Drop-outs (%): 0 

Comments: Vit B12 and folate assessed by use of solid phase radioassay kits Other predictors/outcomes reported: Behavioral testing (Behave AD; cohen Mansfield Agitation; verbally agitated behavior; corFollow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Compared to fronto temporal dementia and only significant correlations available Quality (A/B/C): C Applicability (1/2/3): 
Appendix C. Evidence Tables 

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Correlation of Predictors with Outcomes (cross-sectional studies) 

Sr B 12 vit pg/mL p Red cell Folate ng/mL p 

Description of (Sub-) Groups 

N 

Mean SD r= Mean SE/SD r= 

AD-HDS 152 382.8 257.8 ND NS 245.5 197.5 0.205 0.03 FTD-HDS 28 316.6 120.0 0.538 0.014 277.2 195.2 ND NS AD-MMSE 152 ND NS ND NS FTD-MMSE 28 ND NS 0.443 0.02 
Appendix C. Evidence Tables 

B Vitamin Evidence Table - Human studies 

C-145 

Correlation

Author, Year: Garcia, 2004 Ref ID: 1063 Vitamins: B12, Fola

Objective: Association with cognitive function in elderly Study characteristics Population Inclusion criteria Exclusion criteria 

XS Age: 73.0 (4.9) Cases: Cases: Non-comparative %Male: 25% 

Study design 

Prospective Race: nd 

Age ≥65 y, Independent-living, attend senior community center 

Oral B12 >37.5 μg/day, Parenteral B12, historileal/gastric surgery, Serum Creatinine >130 mneurological disease (eg, dementia, stroke, sevtrauma, PD), depression, MMSE<24, hospitaliwithin prior 3 months, any acute medical cond

Country: Canada MMSE: 28.3 (1.52) Controls: Controls: Setting: Community Funding: Private non-profit Comments: Predictor(s): (eg, B vit level) 

Outcome(s): Definition: 

Serum Vit B12* 

pmol/L Mattis DRS screening for dementia, includes subtests for attention, 

initiation, perseveration, construction, conceptualization, and memory 

N enrolled: 

(RBC Folate** 

nmol/L) Stroop 

Neuropsychological Screening Inventory 

 California Verbal 

Learning Test (CVLT) 

Verbal learning characteristics in 5 categories: recall 

measures, learning characteristics, recall errors, recognition measures, and contrast measures. Each metric analyzed separately. Appears that for each outcome, the metric that was most strongly correlated was marked as “Factor 1” and analyzed alone. Each outcome thus analyzed against different metrics of the CVLT. 

N analyzed: 

Drop-outs (%): 

Comments: * Standard radioimmunoassay. Normal range 165-740 pmol/L ** Standard radioimmunoassay. Normal range 200-1300 nmol/L. Measured, but no analyses reported. 
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Other predictors/outcomes reported: Methylcitric acid, MMA, Hcy Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Analyses opaque Quality (A/B/C): C Applicability (1/2/3): Outcome(s): Results (Text) CVLT Analysis unclear and very difficult to interpret. Authors conclude that Vitamin B12 levels did not significantly 

analysis with the psychometric measures 

Correlation of Predictors with Outcomes (cross-sectional studies) 

Stroop (Max 112) Mattis (Max 144) 

Description of (Sub-) Groups 

N 

Mean SD r=

p 

Mean SD r= 

p 

Low Vit B12 44 83.4 21.4 NS 138.8 4.7 NS Normal Vit B12 237 82.7 18.8 139.0 4.2 
Appendix C. Evidence Tables 

B Vitamin Evidence Table - Human studies 

C-147 

Correlation

Author, Year: Gold, 1995 Ref ID: 1119 Vitamins: Thiamine 

Objective: Thiamine levels among patients at memory clinic Study characteristics Population* Controls** Inclusion criteria Exclusion 

criteria 

D

XS Age: 77.8+/-7.7 74.9+/-6.4 Cases: Cases: Non-comparative %Male: 18% 47% 

A

Study design 

Prospective Race: nd nd 

Under evaluation for cognitive impairment P

Country: US Other: Controls: Controls: VSetting: Clinic OFunding: nd * Diagnosed with Senile dementia of Alzheimer’s type (SDAT) ** Non-SDAT Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population of Plasma thiamine* ng/mL MMSE N enrolled: nd RBC thiamine* ng/mL Diagnosis of AD N analyzed: 34 

Drop-outs (%): 

Comments: *Microbiologic assay (Kloeckera apiculata). Thiamine deficient defined as below age-matched normal range. 

 Plasma: Normal mean (range): Age 61-80: 12.0 (8-26); Age 81+: 11.0 (10-12.6) ng/mL  RBC: Normal mean (range): Age 61-80: 146.0 (89-205); Age 81+: 140.0 (131-163) ng/mL Other predictors/outcomes reported: 

Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Authors note possibility that some “non-SDAT” patients may also have AD (in addition to other 

Definition of low thiamine vague and age-dependent in a non-consistent manner (normal mean lend of range higher). 

Quality (A/B/C): C Applicability (1/2/3): Outcome(s): Results (Text) MMSE There was no significant difference in MMSE scores between patients with probably SDAT with low plasma th

with normal plasma thiamine levels (P=0.11). 
Appendix C. Evidence Tables 

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Correlation of Predictors with Outcomes (cross-sectional studies) 

Plasma B1 ng/mL p Plasma B1 Low* p RBC B1 ng/mL p R

Description of (Sub-) Groups 

N 

Mean SD n % Mean SD 

SDAT 17 7.5 4.1 11 65% 149.9 34.6 Non-SDAT 17 12.6 5.4 0.002 2 12% <0.001 168.0 47.8 0.07 * Age 61-80: <8 ng/mL; Age 81+: <10 ng/mL ** Age 61-80: <89 ng/mL; Age 81+: <131 ng/mL 
Appendix C. Evidence Tables 

B Vitamin Evidence Table - Human studies 

C-149 

Correlation

Author, Year: Gold, 1998 Ref ID: 1120 Vitamins: Thiamine 

Objective: To explore the extent of thiamine deficiency in neurodegenerative by determining the plasma and RBC thiamine level

comparing the results to a previous group of probable AD patients (Gold et al 1995) 

Study characteristics Population p-AD PD Inclusion criteria Exclusion criteria Definiti

XS Age: 77.8+/-

7.7 

71.3 

(8.7) 

Cases: Cases: 

Comparative %Male: 18% 61% 

AD: 

Study design 

Retrospective 

Race: nd nd 

AD recruited from Memory Disorders Clinic who were ambulatory and were living at home, either independently or with a dedicated caregiver. PD patients recruited from Movement Disorders Clinic. The inclusion criteria were age >50 and a diagnosis of Parkinson’s disease. All patients were receiving dopaminergic meds and had significant clinical responses 

Patients with any h/o gastric, digestive diseases, of gastric or intestinal resections, or of malabsorption syndrome 

PD: 

Country: US Other: Controls: Controls: VascDzSetting: Academic 

hospital 

Other: 

Funding: nd 

None 

Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population of i

 AD 

Plasma thiamine* ng/mL Levels in AD patients N enrolled: 50 17 Erythrocyte thiamine* ng/mL Levels in AD patients N analyzed: 50 17 

Drop-outs (%): nd 

Comments: * Non fasting levels assessed by using a bioassay (Lactobacilli agar) 
Appendix C. Evidence Tables 

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Other predictors/outcomes reported: None Follow-up duration (if applicable): A group of PD patients compared to those with AD from a different year Reasons for drop out (if applicable): Limitations: Quality (A/B/C): B Applicability (1/2/3): Outcome(s): Results (Text) Plasma thiamine levels 

Statistical analysis demonstrated that patients with pAD had sig lower raw plasma thiamine levels (p<0.001) an

thiamine levels (p<0.01) than patients with PD. 

RBC thiamine levels No significant differences were noted in the raw RBC thiamine levels or z score RBC thiamine levels between 

A sig higher number of AD patients were plasma thiamine deficient than PD patients (p<0.001) No correlation between RBC and plasma thiamine levels for either group of patients 

Correlation of Predictors with Outcomes (cross-sectional studies) 

Pl Thiamine ng/mL p RBC B1 ng/mL p MMSE scores 0- 30 Pl 

def

pa

Description of (Sub-) Groups 

N 

Mean SD r= Mean SD r= Mean SD r= P Mean S

AD 17 7.5 4.1 <0.001 149.9 34.6 NS 17.6 7.7 <0.001 PD 33 11.06 4.08 146.8 43.1 26.8 4.1 
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C-151 

Correlation

Author, Year: Goodwin, 1983 Ref ID: 1129 Vitamins: B1, ribofl

Objective: To examine the hypothesis that subclinical malnutrition may be associated with age-related changes in cognitive functStudy characteristics Population Inclusion criteria Exclus

criteria 

XS Age: 72 (60-94) Non-comparative %Male: 46% 

Study design 

Prospective Race: ND 

Country: US Other: 85% finished 

high school and 

49% finished 

college 

Ambulatory and living independently and recruited from Albuquerque area in early 1979 with 1) age of 60 yrs or older 2) no prescription medication or daily nonprescription meds 3) no known serious medical diagnoses eg cancer, aortic stenosis, diabetes or TIA while patients with osteoarthritis or cataracts included as long as they were not receiving medications

Those wmedical and on pmeds (nincomplintake, vlevels, oassessmsubjects administhe cogn(n=7)

Setting: Academic hospital Funding: Gov and Private foundation Comments: 
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Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Folate, thiamine, riboflavin, pyridoxine, and vitamin B12 nutrient intake 

Dietary intakes were measured by 3-day food record, weighting all food items on a portable scale. 

Cognitive tests 

HalsteadReitan categories test 

N enrolled: 

304 

 Wechsler 

verbal memory test 

N analyzed: 

260 

Drop-outs (%): 

14% 

Folate, thiamine, riboflavin, pyridoxine, and vitamin B12 blood levels 

Fasting blood samples. The assessment of thiamine and riboflavin 

was determined by a functional assay; ie, transketolase and glutathione reductase, respectively. 

Plasma levels of folate (RBC) and 

vitamin B12 were determined by competitive binding radioassays. 

Dietary intake categories Bottom 5%, bottom 10%; top 90% Comments: Halstead Reitan categories test was a nonverbal automated test of abstract thinking and problem 

sensitive indicator for minimal changes in mental status All correlations were controlling for age and sex of the subjects.

Other predictors/outcomes reported: Protein intake, vitamin C intake and blood levels Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Data analyze for completers only. No means of intakes or blood levels were reportQuality (A/B/C): B Applicability (1/2/3): Outcome(s): Results (Text) Mean scores of halstead Reitan Categories test 

There was a trend for those subjects in the bottom 5% or 10% of dietary intake of all nutrients to do poorly on t

rest of the population except for folate 

Mean scores of Wechsler Memory test 

There was a trend for those subjects in the bottom 5% or 10% of dietary intake of all nutrients to do poorly on t

90% of the population 

Mean scores of halstead Reitan Categories test 

There was a trend for those subjects in the bottom 5% or 10% of blood levels of specific nutrients riboflavin, vi

poorly on the test compared with the rest of the population 
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Mean scores of Wechsler Memory test 

Statistically significant deficiencies in performance were seen in those with low levels of vit B12 

Correlation of dietary intake levels of B vitamins with cognitive function (cross-sectional studies) 

Description Folate Thiamine Riboflavin Pyridoxine Vit B12 of (Sub-) Groups 

N 

r= 

p 

r= 

p 

r= 

p 

r= 

p 

r= 

p 

Halstead Reitan Categories test 

260 .00 NS -.02 NS .05 NS -.04 NS -.04 NS 

Wechsler verbal memory test 

260 -.06 NS -.02 NS .02 NS -.02 NS -.02 NS 

Correlation of blood levels of B vitamins with cognitive function (cross-sectional studies) 

Sr Folate ND p Sr Thiamine ND p Sr Riboflavin ND 

Description of (Sub-) Groups 

N 

Mean SE/SD r= Mean SE/SD r= Mean SE/SD r= M

Halstead Reitan Categories test 260 0.08 NS .02 NS .02 NS Wechsler verbal memory test 260 -.03 NS 

-

.04 NS .14 <0.05* 

* Remained sig in a multivariate analysis controlling for age and sex of the subjects 
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Correlation

Author, Year: Gottfries, 2001 Ref ID: 1145 Vitamins: B12, Fola

Objective: Correlation of B vitamins (etc.) with cognitive impairment Study characteristics Population Inclusion criteria Exclusion criteria Definitions 

XS Age: 70.4 Cases: Cases: Comparative %Male: 46% 

Alzheimer Type of Dementia (DAT): 

Study design 

Prospective Race: nd 

Ambulatory, age ≥50 yr, complaining about cognitive disturbances in an outpatient memory clinic. 

Plasma B12 >600 pmol/L, Plasma folate > 30 nmol/L, or Serum creatinine >100 nmol/L (to exclude those taking supplements or with insufficient kidney excretion, thus elevating homocysteine) 

Mild Cognitive Impairment: 

Country: Sweden Other: Controls: Controls: Vascular 

Dementia (VAD

Setting: Outpatient 

memory unit 

Subjective Memory Complaints: 

Funding: nd Comments: VAD = vascular dementia Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population Plasma B12* pmol/L 4 diagnostic groups As defined above N enrolled: CSF B12** pmol/L CSF B12/Blood B12*** x1000 Plasma Folate  nmol/L 

N analyzed: 

Blood Folate** *** nmol/L Drop-outs (%): Comments: * No data on measurement method. Normal range 150-700 pmol/L ** No data on measurement method. Normal range is unknown. *** Normal range is unknown   No data on measurement method. Normal range 6-39 nmol/L ** *** No data on measurement method. Normal range 140-380 nmol/L 
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Other predictors/outcomes reported: Serum and CSF Homocysteine, Serum and CSF MMA, CSF Tau protein, CSF/Serum album

pathology, vascular risk factors, EEG 

Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Reported values are not adjusted for potential confounders. Numbers of subjects in each anaQuality (A/B/C): C Applicability (1/2/3): Outcome(s): Results (Text) Correlation of Predictors with Outcomes (cross-sectional studies) 

Plasma B12 pmol/L p Plasma B12 p CSF B12 pmol/L p CS

Description of (Sub-) Groups 

N* 

Mean SD % <150 pmol/L Mean SD 

DAT ≤43 355.8 130.9 0% 13.9 10.0 Mild Cog Impair ≤32 295.8 93.6 6.3% 11.3 5.8 VAD ≤14 272.2 105.5 7.7% 10.8 6.3 Subj Memory Compl ≤12 330.2 113.3 

NS 

8.3% 

NS 

14.4 6.4 

NS 

* 101 in total cohort (43+32+14+12). However, Plasma B12 had N=99; CSF B12 had N=80. ** “Numerically higher [than other groups], which would suggest a better transport of vitamin B12 into the brain in this group.” 

Plasma Folate nmol/L p Plasma Folate p Blood Folate nmol/L p B

Description of (Sub-) Groups 

N* 

Mean SD % <6 nmol/L Mean SD % 

nm

DAT ≤43 12.2 4.5 0% 237.5 78.7 5Mild Cog Impair ≤32 14.1 6.9 6.3% 253.8 90.0 4VAD ≤14 11.4 4.6 7.7% 267.0 145.5 Subj Memory Compl ≤12 12.7 5.1 

NS 

0% 

NS 

282.5 86.5 

NS 

* 101 in total cohort (43+32+14+12). However, Plasma Folate had N=98 and Blood Folate had N=74. 
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Correlation

Author, Year: Haller, 1996 Ref ID: 1239 Vitamins: Folate and 

Objective: Assessment of the mental health of the European elderly and its correlations with micronutrient plasma levels, educati

activities of daily living 

Study characteristics 

Population Controls Inclusion criteria Exclus

criteria 

XS Age: Cases: CasesNon-comparative %Male: 49% 

Study design 

Prospective Race: 

Randomized sample of both sexes born in the period 1913 to 1918. 

Country: 9 European 

countries 

Other: Controls: Contro

Setting: Funding: Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population of folate MMSE score N enrolled: 885 885 cobalamin MMSE score N analyzed: 885 885 

Drop-outs (%): 

Comments: Other predictors/outcomes reported: Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: method of randomization not stated Quality (A/B/C): C Applicability (1/2/3): 3 Outcome(s): Results (Text)  There were highly significant but weak correlations between the total MMSE scores and the coblamin and folat
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Correlation of Predictors with Outcomes (cross-sectional studies) 

Description (Sr/CSF) folate (unit) p (Sr/CSF) cobalamin (unit) p of (Sub-) Groups 

N 

Mean SE/SD r= Mean SE/SD r= 

MMSE overall 885 0.103 <0.01 0.125 <0.001 MMSE men 

433 ND 0.161 <0.001 

MMSE women 

452 0.113 <0.05 ND 
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Correlation

Author, Year: Jelicic, 2002 Ref ID: 1498 Vitamins: Vitamin B

Objective: To examine the effects of low levels of vitamin B12 and folate in older adults on speed of information processing and Study characteristics Population Controls Inclusion criteria Exclusio

criteria 

XS Age: 68.7 Cases: Cases: Comparative %Male: 47% 

Study design 

Retrospective Race: 

Non-demented older people who underwent blood tests 

Country: The Netherlands Other: Controls: ControlsSetting: Genral 

population 

Funding: Dutch Ministry of Health, Welfare and Sports Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total PoGroup 1: normal B12 & folate levels N enrolled: 698 Group 2: normal B12 & low folate levels N analyzed: 698 Group 3: low B12 & normal folate Drop-outs 

(%): 

0 

Group 4: low B12 & folate 

Memory and speed of information processing 

Comments: There were differences between the study groups with respect to age and education. Other predictors/outcomes reported: Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Quality (A/B/C): B Applicability (1/2/3): 
Appendix C. Evidence Tables 

B Vitamin Evidence Table - Human studies 

C-159 

Outcome(s): Results (Text): ANOVA was used to determine whether the 4 groups differed with regard to cognitive 

and education as covariates. 

 1. No significant differences in memory performance were found.  2. Borderline significant differences (p=0.087) between the 4 groups with respect to speed of information proce 3. Post hoc analyses using ANOVA with age and education as covariates showed that Group 1 (normal B12 & 

performance on the coding task than group 3 (low B12 only), p<0.05. 

 4. The other post hoc analyses were not significant.  5. ANOVA with age and education as covariates revealed that particpants with normal B12 outperformed those 

task. 

Correlation of Predictors with Outcomes (cross-sectional studies) 

Memory 

score (unit) p

Speed of 

information 

processing 

 (unit) p 

Description of (Sub-) Groups 

N 

Mean SD r= Mean SD r= 

Group 1: normal B12 & folate 469 19.9 6.1 38.8 11.7 Group 2: normal B12, low folate 100 18.7 5.5 36.1 9.7 Group 3: low B12, normal folate 98 18.6 5.6 34.1 11.1 Group 4: low B12 & folate 31 16.9 4.2 30.3 10.8 
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C-160 

Correlation

Author, Year: Jimenez-Jimenez, 1999 Ref ID: 1507 Vitamins: thiamine 

Objective: To assess the lumbar CSF levels of thiamine and their phosphate esters in pts with PD compared with a control populaStudy characteristics Population Controls Inclusion criteria Exclusion criteria 

XS Age: 64 63 Cases: Cases: Comparative %Male: 58 40 

Study design 

Retrospective Race: ND ND 

PD Vitamin in last 6 mo, ETOH >80 g/

in last 6 mo, previous hx of chronic liver disease, CRF, gastrectomy, pancreatic diseases, malabsorption, atypical diets, undernutrition, seversystemic disease 

Country: Spain Other: Controls: Controls: Setting: 2 urban 

hospitals 

Funding: Comunidad de Madrid & Fundacion 

Neurociencias y Envejecimiento 

‘healthy’: suspected subarachnoid hemorrhage, psuedotumor cerebri, oculomotor palsies or other neurological dx that required LPs 

Same as above 

Comments: 7/24 pts with PD untreated; control population had suspected neurological problems other than PD Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population of Free and total thiamine N enrolled: 64 24 Thiamine-diphosphate N analyzed: 64 24 Thiamine-monophosphate Drop-outs (%): 0 Comments: Analysis of thiamine by ion-pair reversed phase HPLC according to Bettendorff et al. Other predictors/outcomes reported: Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: control group not healthy Quality (A/B/C): C Applicability (1/2/3): 
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C-161 

Outcome(s): Results (Text)  1. The mean CSF levels of thiamine-diphosphate, thiamine-monophosphate, and total thiamine of PD pts 

significantly from those of controls, although free CSF thiamine levels were significantly lower in the 

2. PD pts treated with levodopa had significantly higher CSF thiamine-diphosphate and total thiamine th

this drug. 

3. No significant correlation in PD pts between the CSF thiamine (in all their forms) and age, age at onse

scores of the Activities of Daily Living and motor examination, and the Hoehn and Yahr staging. 

4. There was no correlation between CSF thiamine levels and the analyzed clinical features of PD. 

Correlation of Predictors with Outcomes (cross-sectional studies) 

CSF 

Thiaminediphosphate 

(nmol/L) 

p CSF 

Thiaminemonophosphate

(nmol/L) 

p CSF 

Free 

thiamine 

(nmol/L)

p CSF 

Total 

thiamine 

(nmol/L)

Description of (Sub-) Groups 

N 

Mean SD Mean SD Mean SD Mean SD 

PD 24 3.9 3.0 4.3 3.3 0.9 1.3 9.1 6.4 Control 40 3.1 2.3 4.3 2.9 1.9 1.4 <0.01 9.3 5.1 PD (+)LDOPA 15 5.1 3.1 5.2 3.6 <0.01 1.1 1.6 11.5 6.7 PD (-)LDOPA 9 2.0 1.5 2.8 2.1 0.4 0.3 5.2 3.7 
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C-162 

Correlation

Author, Year: Jones, 2002 Ref ID: 1533 Vitamins: B12, folic 

Objective: To examine the variability in rate of decline during the last 3 yr before the diagnosis of AD could be linked to particip

demographic, health related, genetic and social domains 

Study characteristics Population Controls Inclusion criteria Exclus

criteria 

Longitudinal Age: ND Cases: CasesNon-comparative %Male: ND 

Study design 

Prospective Race: Probably 

white 

All inhabitants aged ≥75 yrs and older in the Kungsholmen Parish of Stockholm, Sweden 

Country: Sweden Other: Controls: ControSetting: Community 

based 

Funding: ND Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population oVit B12 ND MMSE (Swedish version) 0-30 N enrolled: 230 230 Folate ND N analyzed: 230 230 

Drop-outs (%): 

Comments: MMSE (Swedish version) administered both at baseline and at follow-up Other predictors/outcomes reported: Demographic factors; disease measures; depression; ApoE genotype Follow-up duration (if applicable): 3 yr Reasons for drop out (if applicable): Limitations: Very incomplete description of results Quality (A/B/C): C Applicability (1/2/3): Outcome(s): Results (Text) Cognitive decline Vitamin status (B12 and folate) did not precipitate (ie, not associated with) the decline 
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C-163 

Correlation

Author, Year: Joosten, 1997 Ref ID: 1536 Vitamins: B12, Fola

Objective: B12, Folate, MMA in AD and controls Study characteristics Population Controls Inclusion criteria Exclusion criteria 

XS/Longitudinal Age: 82.8+/-

4.9 

1. 81.1+/-

5.8 

2. 79*+/-

5.9 

Comparative %Male: 37% 1. 42% 

2. 33% 

Study design 

Prospective Race: nd nd 

Cases: Age >70 y, admitted to acute geriatric ward, screened in for probable AD

Cases: Vitamin supplement, blood transfusion, lifethreatening disease

Country: Belgium Other: Controls: Controls: Setting: Hospital and 

Home 

Funding: Pharmaceutical 

1. Age >70 y, admitted to acute geriatric ward, screened out for probable AD, age and sex matched 2. Age >70 y, healthy, living at home independently 

1. Vitamin supplement, blood transfusion, lifethreatening disease 2. Same as 1 + Malignancy, vascular disorder 

Comments: * Significantly different than AD (P<0.001) Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population of intSerum Vit B12* ng/L AD diagnosis N enrolled: 151 52 Serum Folate** μg/L N analyzed: 151 52 MMA nmol/L Hcy μmol/L 

Drop-outs (%): 

Comments: * Amersham, radioimmunoassay. Normal range 140-550 ng/L. ** Amersham, radioimmunoassay. Normal range 2.4-7.2 μg/L. Other predictors/outcomes reported: Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Quality (A/B/C): C Applicability (1/2/3): 
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Correlation of Predictors with Outcomes (cross-sectional studies) 

Serum B12 ng/L p Serum B12 <139 ng/L p Serum Folate μg/L p Seru

Description of (Sub-) Groups 

N 

GeoMean 95% range r= Prevalence GeoMean 95% range r= Prev

AD 52 284 (80-999) NS 3.8% NS 3.5 (1.3-9.7) NS 2Hospitalized, non-AD 50 281 (89-887) 10% 4.0 (1.5-10.9) Healthy 49 284 (119-673) 6.1% 3.8 (1.8-8.2) 6GeoMean, geometric mean 
Appendix C. Evidence Tables 

B Vitamin Evidence Table - Human studies 

C-165 

Correlation

Author, Year: Malaguarnera, 2004 Ref ID: 1972 Vitamins: Pyridoxal 

Objective: To evaluate the relationship between the plasma Hcy levels and the vitamins involved in its metabolism in cognitive dStudy characteristics Population Controls Inclusion criteria Exclusion 

criteria 

Definitions 

XS Age: 72.6 

(7.38) 

73.7 (4.2) Cases: Cases: 

Comparative %Male: 32% 50% 

AD: NINCDS-A

confirmed that showenormal aspall patients 

Study design 

Prospective Race: ND ND 

AD patients: all those who presented with progressive cognitive deficit for at least one year VascDz: ND 

PD: 

Country: Italy Other: Controls: Controls: VascDz: NINDS-AI

confirmed subcortical involvemenmatter 

Setting: Academic 

hospital 

Other: 

Funding: ND 

ND 

Normal healthy 

Clinically aout cogniti

Comments: (B12 and folate not extracted as total n<100) Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population of Pyridoxal phosphate levels nmol/L Dementia AD N enrolled: 68 22 

N analyzed: 68 22 Drop-outs (%): 

Comments: * included only patients with AD and healthy (vascdz n=22 not included) PLP measured by radio-enzymatic assay 
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Other predictors/outcomes reported: Hcy, folate, vit B12, cholesterol, HDL, TG, LDL Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Small N and XS Quality (A/B/C): C Applicability (1/2/3): Correlation of Predictors with Outcomes (cross-sectional studies) 

Sr PLP nmol/L p 

Description of (Sub-) Groups 

N 

Mean SD 

AD 22 52.0 10.78 NS Healthy controls 24 57.5 8.19 
Appendix C. Evidence Tables 

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C-167 

Correlation

Author, Year: Mastrogiacoma, 1996 Ref ID: 2032 Vitamins: B1 

Objective: To evaluate the status of brain thiamine and its phosphate esters in AD Study characteristics Population Controls Inclusion criteria Exclusion 

criteria 

Definitions 

XS Age: 73 

(2) 

70 (3) Cases: Cases: 

Comparative %Male: ND ND 

AD: Pr

pltananabpr

Study design 

Retrospective Race: ND ND 

Tissues from the autopsied brains of confirmed patients with AD 

ND 

PD: 

Country: Canada and 

Belgium 

Other: Controls: Controls: VascDz:

Setting: Academic 

hospital 

Other: 

Funding: Multi Gov funds and student award 

neurologically and histopathologically normal control subjects matched with respect to age, post mortem status, premortem agonal status, cerebral cortical pH and lactic acid levels 

ND 

Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Pop

i

Free non-phosphorylated thiamine 

ND Cerebral cortical levels (temporal, parietal, 

occipital) 

N enrolled: 38 

Total thiamine ND N analyzed: 38 

Drop-outs (%): 

Comments: 
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Other predictors/outcomes reported: Thiamine dependent enzymes Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Autopsy study and no correlation with sr levels Quality (A/B/C): C Applicability (1/2/3): Outcome(s): Results (Text) Total thiamine Levels of total thiamine were normal in all three brain areas, a non significant trend towards reduction predomi

occipital cortices 

Correlation of Predictors with Outcomes (cross-sectional studies) 

Temporal 

cortex Thiamine pmol/mg of protein p Temporal cortex Total thiamine pmol/mg of protein Description 

of (Sub-) Groups 

N 

Mean SE % of change Mean SE % of change 

AD 20 9.0 0.7 -1 NS 27.2 1.4 -11 Controls 18 9.0 0.7 NS 30.7 1.3 

Parietal 

cortex Thiamine pmol/mg of protein p Parietal cortex Total thiamine pmol/mg of protein Description 

of (Sub-) Groups 

N 

Mean SE % of change Mean SE % of change 

AD 20 9.9 0.8 +9 NS 29.5 1.4 -5 Controls 18 9.1 0.6 NS 31.1 1.3 

Occipital 

cortex Thiamine pmol/mg of protein p Occipital cortex Total thiamine pmol/mg of protein Description 

of (Sub-) Groups 

N 

Mean SE % of change Mean SE % of change 

AD 20 10.1 0.8 -8 NS 27.9 1.4 -12 Controls 18 11.0 0.7 NS 31.6 1.3 
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C-169 

Total thiamine=thiamine monophosphate+thiamine+thiamine diphophate 
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B Vitamin Evidence Table - Human studies 

C-170 

Correlation

Author, Year: Maxwell, 2002 Ref ID: 2072 Vitamins: Folate 

Objective: Association of folate level with future dementia Study characteristics Population Inclusion criteria Exclusion 

criteria 

D

Longitudinal Age: 80.1 SD 7.3 Cases: Cases: Non-comparative %Male: 45% 

A

Study design 

Prospective Race: nd P

Country: Canada Other: VSetting: Community and 

Institutions 

CimnD

Funding: Government; Pharmaceutical 

Canadian Study of Health and Aging (CSHA). Representative sample of Canadians aged 65 years and older. 18 centers in 5 regions across Canada. Both community and residents of institutions. All subjects scoring <78 on Modified Mini-Mental State (3MS) examination, random sample of those scoring ≥78, subjects unable to be screened, all institutionalized subjects invited for comprehensive clinical examination. No clinical dementia (at baseline) per DSM-III-R. Available folate data Re-contacted after 5 years. 

Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Folate quartile (by study center)* Q1: <5-12 nmol/L Modified Mini-Mental State (3MS), Baseline 0-100 N met incl Q4: >14-36 nmol/L Cognitive decline ∆ 3MS ≥10 N analyze

Dementia DSM-III-R 

AD ?DSM-III-R 

Not analyz

Comments: * ND on measurement method or normal range. Other predictors/outcomes reported: Adverse cerebrovascular event (primary outcome), death, institutionalized Follow-up duration (if applicable): 5 years Reasons for drop out (if applicable): Newfoundland (legal restrictions) 33; missing clinical data 47; no data 177-217 Limitations: High proportion of unanalyzed subjects, without explanation Quality (A/B/C): B Applicability (1/2/3): 2 
Appendix C. Evidence Tables 

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Correlation of Predictors with Outcomes 

All Q1 Folate <5-12 nmol/L Q2 Folate (nd) Q3 Folate (nd) Q4 Folate 

Outcome N 

Mean SD 

N 

Mean SD 

N 

Mean SD 

N 

Mean SD 

N 

Mean 

Baseline 3MS Score 369 74.8 15.8 80 66.6 19.2 100 77.8 3MS Decline (5 yr) 266 N=87 nd 43.5% nd 32.4% nd 29.3% nd 29.7% Dementia (incident) 243 N=66 nd 38.1% nd 27.3% nd 23.1% nd 24.3% AD (incident) 226 N=49 nd 33.3% nd 21.3% nd 15.3% nd 20.9% * Odds Ratio (95% confidence interval), adjusted for age and sex. 
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Correlation

Author, Year: McCaddon, 2004 Ref ID: 2088 Vitamins: B12 

Objective: Association of B12 and transcobalamin polymorphism with AD (Clinical study) 

Study characteristics Population Controls Inclusion criteria Exclusion criteria 

XS Age: 79 

(75-84) 

79 

(73-84) 

Cases: Cases: 

Comparative %Male: 30% 38% 

Study design 

Prospective Race: nd 

Features compatible with DSM-IV criteria for primary degenerative dementia of Alzheimer type 

Receiving B12 supplementation (foB12 correlation) 

Country: UK Other: Controls: Controls: Setting: Dementia 

clinic, outpatient 

Funding: Government 

Healthy, cognitively intact, age and sex matched elderly volunteers from a General Practice in a comparable SES area. 

Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total B12, serum* ng/L AD diagnosis N enrolled: 144 Holo-transcobalamin** pmol/L N analyzed: 136 Transcobalmin isotype TC 776C>G Drop-outs (%): 6% Comments: * Bayer ACS:180 SE, chemiluminescence. ND on normal mean or range. ** Axis-Shield, solid-phase capture assay. ND on normal mean or range. Other predictors/outcomes reported: Holo-TC levels (the ability of transcobalamin to bind to cobalamin) Follow-up duration (if applicable): Reasons for drop out (if applicable): nd Limitations: Numbers of subjects analyzed for B12 unclear. Unclear why dropouts. Combination of clinical and histopathology 

of autopsy cases) problematic 

Quality (A/B/C): C Applicability (1/2/3): 3 
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Correlation of Predictors with Outcomes (cross-sectional studies) 

Sr B12 ng/L p Sr Holo-TC ng/L p N 776CC 776CG 776GG p 776C 

Description of (Sub-) Groups 

N 

Mean range Mean range % % % Allele F

AD 47* 333 272-420 43 (30-62) 65 25% 52% 23% 0.51 Healthy control 74 342 296-455 52 (33-77) 71 37% 51% 12% 0.62 

difference: 0.23 0.18 NS** 

* 23 subjects receiving B12 supplementation were excluded. Unclear if all had AD, but we assume this to be the case. 

** The distribution is in Hardy-Weinberg equilibrium. There is a non-significant increase in TC776G allele frequency in the clinically 

Survival Curve Evaluation of Combined Clinical and Histopathology Studies Outcome(s): Results (Text) 

Age of disease onset N (AD)=74 clinical (living) + 35 histopathology cases (autopsy) 

N (Control)=70 clinical + 107 histopathology AD-free survival significantly greater for 776CC than either 776GG (P=0.008) or 776CG (P=0.02). 

Proportionately fewer people with 776CC appeared to develop AD at any given age. 
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Correlation

Author, Year: McCaddon, 2004 Ref ID: 2088 Vitamins: B12 

Objective: Association of B12 and transcobalamin polymorphism with AD (Histopathology study) Study characteristics Population Controls Inclusion criteria Exclusion 

criteria 

XS Median 

Age (at death): 

80 

(75-85) 

78 

(70-83) 

Cases: Cases: 

Comparative %Male: 38% 53% 

Study design 

Retrospective Race: nd nd 

Histopathologically confirmed AD post-mortem (CERAD criteria) 

Country: Sweden Other: Controls: Controls: Setting: Autopsy (Brain 

bank) 

Funding: Government 

Died from cardiac disease or malignancy. No history of dementia or neuropsychiatric diseases 

Macroscopic infarcts, AD 

Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Transcobalmin isotype TC 776C>G AD diagnosis N enrolled: 201 

N analyzed: 201 Drop-outs (%): 

Comments: Other predictors/outcomes reported: ApoE genotype Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Autopsy study with matched controls from brain bank; unadjusted Quality (A/B/C): C Applicability (1/2/3): 
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Correlation of Predictors with Outcomes (cross-sectional studies) 

776CC 776CG 776GG p 776C 776G p 

Description of (Sub-) Groups 

N 

% % % Allele Frequency 

AD 94 34% 48% 18% 0.58 0.42 Non-AD control 107 39% 47% 14% 0.63 0.37 

difference: NS NS 

See McCaddon 2004 RefID 2088 for combined study survival curve.
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C-176 

Correlation

Author, Year: Miller, 2002 Ref ID: 2167 Vitamins: B12, folat

Objective: To investigate plasma Hcy, B6 status and the occurrence of vascular disease in patients with AD Study characteristics Population Controls Inclusion criteria Exclusion 

criteria 

Definitions 

Case-control Age: 79 

±7 

75 ± 6 Cases: Cases: 

Comparative %Male: 35 46 

AD: Acco

NINC(REF 

Study design 

Retrospective Race: ND ND 

Subjects with Dx of possible or probable AD 

ND 

PD: 

Country: US Other: Controls: Controls: VascDz: Setting: Other: Funding: Government 

Volunteers of similar age without Dx of AD or other major neurodegenerative disease 

ND 

Coexisting vascular disease (VD): 

Hx stCADcerebdocu

Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population oPlasma PLP AD NINCDS/ARDRA criteria N enrolled: 80 43 

N analyzed: 80 43 Drop-outs (%): ND ND 

Comments: Serum PLP was determined by radioenzymatic assay (ALPCO, Windham, NH); considered as low when Other predictors/outcomes reported: Age, gender, RBC folate, plasma B12, serum CRE, serum TSH, medication use 

supplements)

Follow-up duration (if applicable): N/A Reasons for drop out (if applicable): Limitations: Statistically significant difference for age between cases and controls; unclear whether controls recruite

community as cases; power calculation not reported 

Quality (A/B/C): B Applicability (1/2/3): 2 Outcome(s): Results (Text) Low PLP (<25nmol/L) 

The OR for low plasma PLP was 12.3 for patients with AD compared with subjects without AD. VD was not si

with low PLP, nor did VD significantly modify the odds among those subjects with AD. 
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Correlation of Predictors with Outcomes (case control studies) Odds ratios for low PLP (<25nmol/L) in patients with AD and control subjects 

Description of (Sub-) Groups 

N OR (Adj 1*) 

AD 43 12.3 1.8-84 p=0.01 AD with VD (vs. AD without VD, n=32) 11 3 0.46-19 p=0.25 VD (AD, n=11 and normal, n=15) 26 0.55 0.12-2.5 p=0.43 * Adj 1, adjusted for age, gender, RBC folate, plasma B12, serum CRE, serum TSH, plasma Hcy 
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Correlation

Author, Year: Miller, 2003 Ref ID: 2170 Vitamins: Homocyst

Objective: To investigate the effect of L-DOPA and B-vitamin status on plasma homocysteine in PD pts Study characteristics Population Controls Inclusion 

criteria 

Exclusion criteria Definit

XS Age: 64 60 Cases: Cases: Comparative %Male: 65% 50% 

Study design AD: 

Prospective Race: 

> 30 yr, Pregnancy; OCP; other 

neurodegenerative diseases; malnutrition, depression or psychotic illnesses, other major medical disorders 

PD: 

Country: US Other: Controls: Controls: VascDzSetting: University 

outpatient clinic 

Other: 

Funding: US government grants Comments: Self-reported use of folate, B-12 or B-6 was similar between groups; more pts in treatment group on MAO B inhibitor 

agonist than in the control group 

Predictor(s): (eg, B vit level) Outcome(s): Definition: Total PopulatioL-DOPA treated PD pts homocysteine N enrolled: 40 Controls: PD pts not treated with L-DOPA folate N analyzed: 40  B-12 Drop-outs (%):  Pyridoxal-5’-phosphate (PLP) Comments: Other predictors/outcomes reported: Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Quality (A/B/C): B Applicability (1/2/3): 2 
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Outcome(s): Results (Text)  Plasma homocysteine was higher in treatment group than control (p=0.018).  Plasma PLP was lower in treatment group than control (p=0.008).  L-DOPA treated group: homocysteine vs. folate, R2=0.487, p<0.001; homocysteine vs. vitamin B12, R2=0.498, 

vs. PLP, R2=0.342, p=0.007. No correlation in the control group. 

Correlation of Predictors with Outcomes (cross-sectional studies) 

plasma folate nmol/L p plasma B-12 pmol/L plasma P

Description of (Sub-) Groups 

N 

 Mean SD r= Mean SD r= Mean 

L-DOPA treated 20 12.8 11.6 375 167 78 9No L-DOPA 20 12.6 10.8 464 249 154 
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Correlation

Author, Year: Mizrahi, 2004 Ref ID: 2189 Vitamins: B12, Fola

Objective: B12, Folate, Hcy in AD and healthy Study characteristics Population Controls Inclusion 

criteria 

Exclusion criteria 

XS Year of 

birth: 

1915*+/-

7.0 

1927*+/-

7.0 

Cases: Cases: 

Comparative %Male: 39% 48% 

Study design 

Prospective Race: Arab Arab 

AD, Arab villagers, 

Country: Israel Other: Controls: Controls: Setting: Rural Funding: 

Healthy, Arab villagers, 

Memory complaints, indications of any inflammatory disorder 

Comments: This region has a high prevalence of AD despite low ApoE ε4 allele frequency *P<0.001 between groups Predictor(s): (eg, B vit level) Outcome(s): : Total Population of intPlasma B12* pmol/L AD Dx N enrolled: 235 79 Plasma Folate** nmol/L N analyzed: 230 75 (Plasma Hcy μmol/L) Drop-outs (%): 2% 5% Comments: * ICN Pharmaceuticals, radioisotope dilution assay. B12 deficiency defined as <125 pmol/L. ** ICN Pharmaceuticals, radioisotope dilution assay. Folate deficiency defined as <3.6 nmol/L. Other predictors/outcomes reported: Follow-up duration (if applicable): Reasons for drop out (if applicable): 2 Outlier Hcy (>54 μmol/L), 2 Outlier B12 (>850 pmol/L), 1 Hcy not availablLimitations: Quality (A/B/C): A Applicability (1/2/3): 
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Correlation of Predictors with Outcomes (cross-sectional studies) 

Plasma Folate nmol/L p Plasma B12 pmol/L p 

Description of (Sub-) Groups 

N 

Mean SD r= Mean SD r= 

AD 75 4.3 (3.2) NS 322.9 (136.0) NS Healthy 155 4.8 (2.6) 350.5 (175.3) 

(Outcome) 

Description of (Sub-) Groups 

N 

OR (Adj 1*) 

Plasma B12 >259.95 pmol/L 1 Plasma B12 203.70-259.95 pmol/L 0.7 (0.3-1.9) Plasma B12 <203.70 pmol/L 

230 

1.3 (0.5-3.4) 

Plasma Folate >11.40 nmol/L 1 Plasma Folate 7.87-11.40 nmol/L 1.3 (0.5-3.7) Plasma Folate <7.87 nmol/L 

230 

1.6 (0.6-4.2) 

* Adj 1, adjusted for year of birth and gender 
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Correlation

Author, Year: Molina, 2002 Ref ID: 2196 Vitamins: B1 

Objective: To assess the lumbar CSF levels of thiamine and their phosphate esters in patients with sporadic AD compared with a 

relate the decreased levels with increased risk of AD 

Study characteristics Population Controls Inclusion criteria Exclusion criteria Definitio

XS and Longitudinal 

Age: 72.6 

(8.8) 

70.2 (7.6) Cases: Cases: 

Comparative %Male: 46% 44% 

AD: 

Study design 

Prospective and retrospective analysis for progression 

Race: ND ND 

Unselected patients recruited during their first visit to neurology clinic in 2 hospitals in Madrid and fulfilling diagnostic criteria of AD 

Therapy with vit supplements in the past 6 mo; ethanol intake >80g/d in past 6 mo; previous h/o chronic illnesses; atypical dietary habits; undernutrition; and previous h/o severe systemic disease PD: 

Country: Spain Other: 

BMI 

24.4 

(4.7) 

28.2 (3.4) Controls: Controls: VascDz

Setting: Academic 

hospital 

Other: 

Funding: Private non industry 

Healthy nondemented and those with normal CSF finding 

Same as above 

Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population of inPlasma thiamine Nmol/L MMSE <23 for AD N enrolled: 65 33 CSF thiamine Nmol/L N analyzed: 65 33 

Drop-outs (%): 0 

Comments: Plasma and CSF thiamine was analyzed by ion pair reversed phase high performance liquid chromatography; norOther predictors/outcomes reported: Follow-up duration (if applicable): Unclear; per yr progression for AD available Reasons for drop out (if applicable): NA Limitations: Unclear how per yr progression was assessed for 20 patients Quality (A/B/C): C Applicability (1/2/3): 
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Outcome(s): Results (Text) MMSE Significant correlation between MMSE and plasma thiamine diphosphate r=0.41, p<0.05 

Free thiamine correlated significantly with MMSE in both AD patients r=0.84; p<0.01 and controls r=0.40, p<0

Correlation of Predictors with Outcomes (cross-sectional studies) 

CSF TDP nmol/L p CSF TMP nmol/L p CSF Free thiamine nmol/L p CSF 

Description of (Sub-) Groups 

N 

Mean SD r= Mean SD r= Mean SD r= Mean 

AD 33 2.55 1.70 NS 3.57 3.84 NS 1.17 3.03 NS 7.29 Controls 32 3.21 2.28 4.30 2.40 2.20 3.20 9.46 

Sr TDP nmol/L p Sr TMP nmol/L p Sr Free thiamine nmol/L p Sr 

Description of (Sub-) Groups 

N 

Mean SD r= Mean SD r= Mean SD r= Mean 

AD 33 2.22 1.74 <.05 1.32 2.02 NS 1.16 1.21 <.05 4.75 Controls 32 3.23 1.87 2.20 3.20 2.61 2.93 7.88 
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Correlation

Author, Year: Morris, 2001 Ref ID: 2229 Vitamins: folate 

Objective: To evaluate the relation between serum tHcy and performance on short delayed-recall tests of elderly men and women Study characteristics Population Controls Inclusion criteria Exclusion criter

XS Age: 70.1±0.5yr Cases: Cases: Comparative %Male: 42 

Study design 

Retrospective Race: 89.2% non-Hispanic white 

Men and women aged ≥ 60yr who 

participated in phase III NHANES (1991-94); available tHcy measured levels 

< 8 yr follow-up; Hstroke; unable to lword: “apple, tablpenny” in one try; who had asked for to be administered language different reportedly spoken 

Country: US Other: 53.7% had smoke previously; 

11.8% had been heavy 

alcohol users at one time; 

36% had taken vitamins, 

minerals within 24h of the 

interview, 12.6% had high 

BP, 38.1% had a household 

income<US$ 20,000/yr 

Controls: Controls: 

Setting: community Education 

years, mean 

12.3 ±0.2 

Funding: ND Comments: Characteristics are given for total population not separately for the comparative groups Predictor(s): (eg, B vit level) Outcome(s): Definition: Total PopulatioRBC folate, serum folate “Apple, table, penny” test Dichotomous outcome 0, >0 N enrolled: 1270 

N analyzed: 1145 Drop-outs (%): 125 

Comments: RBC folate and serum folate was measured according to standardized protocol
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C-185 

Predictor(s): (eg, B vit level) Outcome(s): Definition: Total PRBC folate, serum folate 

Patients in the upper half of the serum folate distribution; patients in the lower half of the serum folate distribution 

Paragraph delayed recall test 

Continuous scale 0-6 

N enrolled: 1200 

N analyzed: 

1141 

Drop-outs (%): 

59 

Comments: Other predictors/outcomes reported: 

tHcy, sex; age; years of education; race-ethnicity; pack-years of cigarette smoking; heavy alcohol use; higblood lead concentration; selenium; TCHOL; triacylglycerol; CRE; Fe; total Calcium; β-carotene; Vit A, Bincome 

Follow-up duration (if applicable): 

N/A 

Reasons for drop out (if applicable): 

Demographic data not available 

Limitations: Unkown whether the population included patients with dementia, etc or not; exact results (β coefficient, et

inconsistencies between text and table legend (Hcy correlation with serum folate) 

Quality (A/B/C): C Applicability (1/2/3): Outcome(s): Results (Text) “Apple, table, penny” test 

Part of the MMSE (REF 14); the subjects’ score on the test is a number from 0 to 3, corresponding to the numbsuccessfully recalled after the delay 

Paragraph delayed recall test 

The test was administered by trained lay interviewers according to a standard protocol (REF 11). All subjects w

would be read to them, subsequent to which they would be asked to repeat the story back to the interviewer. Thcontinued with a few additional questions unrelated to the story or to cognitive function. Finally, the subjects wstory a second time. The was scored according to the 6 main story ideas recalled by the subjects after the brief d

characteristic of a type of test commonly used to evaluate short-term verbal memory (REF 15). Also such tests 

effective at distinguishing between subjects who will and will not progress to a Dx of AD 

Paragraph delayed recall test 

Patients in the upper half of the serum folate distribution recalled on average >4 of the 6 main ideas of the story

of the serum folate distribution recalled significantly fewer stories (p<0.001) 
Appendix C. Evidence Tables 

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C-186 

Correlation of Predictors with Outcomes (cross-sectional studies) Folate levels in different groups according to paragraph delayed recall test score 

Sr folate nmol/L p RBC folate nmol/L p (Sr/CSF) (B vit) (unit) (S

Description of (Sub-) Groups 

N 

Mean SE/SD r= Mean SE/SD r= Mean SE/SD r= M

Paragraph delayed recall test 0 37 12.3 ND ND 464 ND ND Paragraph delayed recall test 1 27 13.5 ND ND 399 ND ND Paragraph delayed recall test 2 82 16.8 ND ND 433 ND ND Paragraph delayed recall test 3 200 18 ND ND 545 ND ND Paragraph delayed recall test 4 333 17.6 ND ND 488 ND ND Paragraph delayed recall test 5 306 18.9 ND ND 534 ND ND Paragraph delayed recall test 6 158 18.4 ND ND 545 ND ND Significant relation with recall score and tHcy levels after adjusted for age, sex, race-ethnicity, years of education, and income (regression model Folate levels in different groups according to “Apple, table, penny” test score 

Sr folate nmol/L p RBC folate nmol/L p (Sr/CSF) (B vit) (unit) (S

Description of (Sub-) Groups 

N 

Mean SE/SD r= Mean SE/SD r= Mean SE/SD r= M

“Apple, table, penny” test 0 37 14.2 ND ND 455 ND ND “Apple, table, penny” test >0 1108 17.8 ND ND 513 ND ND Serum folate concentration interacted significantly with the serum tHcy concentration in relation to story recall but not to word 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Human Studies 

C-187 

Correlation

Author, Year: Nagga, 2003 Ref ID: 2275 Vitamins: Folate 

Objective: 

Study characteristics Population Controls Inclusion criteria Exclusion criteria 

XS Age: 

AD* AD w/CVD* VD* Cognitive impaired

75 76 78 75 

69 Cases: Consecutive 

patients evaluated for dementia from January 1995 – December 1997, 

Cases: Current cobaand/or folate substitusubgroup N < 3 

Comparative %Male: 37 51 

Study design 

Prospective Race: ND 

Country: Sweden Other: Controls: Controls: Setting: In/out-patient geriatric 

clinic of university hospital 

Funding: Public & private 

≥ 60 yr, randomly selected from general population screened for gastritis with gastroscopy, biopsy, & blood samples in fasting state, no MMSE data

Comments: *Statistical lower age for controls vs population, except mild cognitive impaired subgroup; differential diagnoses 

treated for dementia at enrollment; no MMSE data for control group 

Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population of i

Serum folate nmol/l Dementia ICD-10 N enrolled: 224 64 (59 VD

N analyzed: 224 Drop-outs (%): NA 

Comments: 

Fluoroimmunoassay – reference range 75-475 nmol/l 

Other predictors/outcomes reported: 

Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Analyses for nonfasting patient group vs fasting control group Quality (A/B/C): C Applicability (1/2/3): 
Appendix C. Evidence Tables 

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C-188 

Correlation of Predictors with Outcomes (cross-sectional studies) 

Sr Folate (unit) p Description of 

(Sub-) Groups 

N Mean SD r= 

AD 47 191 75 AD w/CVD 9 165 89 Cognitively impaired 8 279 115 <.05 Control 101 ND ND 

AD & AD w/CVD had lower levels of blood folate vs cognitively impaired 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Human Studies 

C-189 

Correlation

Author, Year: Nilsson, 1996 Ref ID: 2337 Vitamins: B 12, fola

Objective: To determine plasma tHcy and its main determinants sr cobalamin, blood folate, and sr creatinine in dementia patients 

population 

Study characteristics Population (DAT) Controls Inclusion criteria Exclusion criteria Definit

XS Age: 75±10 75±7 Cases: Cases: Comparative %Male: ND 52 

AD: 

Study design 

Prospective Race: Probably 

white 

Elderly patients with suspected dementia or other organic brain diseases and referred to the psychogeriatric dept in good nutritional status 

Ongoing or those with recently discontinued vit supplementation, or with creatinine >120 μmol L-1, 

patients on extreme diets 

PD: 

Country: Sweden Other: Controls: Controls: VascDSetting: Academic 

hospital 

Other: 

Funding: University and private non-industry 

Local population invited for participation in the study 

Unwilling or unable to participate, younger than 60 yr, or sr creatinine >120 μmol L-1

Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population of Sr cobalamin* 110-650 pmol/L DAT ND N enrolled: 295 68 Blood folate** 125-500 nmol/L N analyzed: 295 68 

Drop-outs (%): 0% 

Comments: Radioassay using vit B12/folate Dual RIA kit Other predictors/outcomes reported: THcy; sr creatinine Follow-up duration (if applicable): NA Reasons for drop out (if applicable): NA Limitations: Xs study; all dementia included for correlational analysis; only levels of B12/folate available for 

for DAT not specified 

Quality (A/B/C): C Applicability (1/2/3): 
Appendix C. Evidence Tables 

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C-190 

Outcome(s): Results (Text) All dementia Significant correlations between the levels of vitamin folate and B12, plasma tHcy in both demented and non d

groups taken together. No data available for DAT alone 

Correlation of Predictors with Outcomes (cross-sectional studies) 

Sr B 12 pmol/L p Sr folate nmol/L p (Sr/CSF) (B vit) (unit) (Sr/C

Description of (Sub-) Groups 

N 

Mean SD r= Mean SD r= Mean SE/SD r= Mea

DAT 68 245 98 ND 294 132 ND <0.05 Controls 163 256 120 353 156 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Human Studies 

C-191 

Correlation

Author, Year: Nilsson, 2003 Ref ID: 2343 Vitamins: B12, folat

Objective: To evaluate the association of biochemical tests with morbidity, drug therapy, anthropometry, and gender Study characteristics Population Controls Inclusion criteria Exclusion 

criteria 

Definiti

XS/Longitudinal Age: M: 84.4 

range: 

82-95 

F: 85.1 

range: 

82-100 

Cases: Cases: 

Comparative %Male: 38 

AD: 

Study design 

Prospective Race: 

Sample from population-based Swedish twin registry: all like-sex (monozygotic and dizygotic) twin pairs aged ≥ 80 with both members still alive during 1991-94 and agreed to give blood samples 

PD: 

Country: Sweden Other: Controls: Controls: VascDzSetting: community Other: Funding: Government (US) Comments: Although study design is for longitudinal study, results for dementia are analyzed as XS (comparison of vit levels amo

certain time-point) 

Predictor(s): (eg, B vit level) 

Outcome(s): Definition: Total Population of in

B12 Dementia DSM-III-R criteria N enrolled: 535 86 folate Dementia DSM-III-R criteria N analyzed: 535 86 

Drop-outs (%): N/A N/A 

Comments: Population (N: 535) also includes people with other morbidities not extracted for the purpose of this project; 256 subj

having intact cognition but it is not clear whether they are compared to demented sub-group); cases on B12-therapy w

analyzed by time-resolved fluoroimmunoassay using an AutoDelfia instrument (Wallac); normal values for B12: 284 pmol/L 

Other predictors/outcomes reported: Albumin, calcium, TCHOL, HDL, -GT, potassium, sodium, urea, urate, CRE, free T4, T

waist circumference 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Human Studies 

C-192 

Follow-up duration (if applicable): N/A Reasons for drop out (if applicable): N/A Limitations: High number of comparisons may lead to significant results by chance; results at a signif

should be interpreted with caution; results and discussion are mixed together with not mu

Quality (A/B/C): C Applicability (1/2/3): 2 Outcome(s): Results (Text) Dementia Folate was significantly lower in women with dementia (p<0.005); NS differences for B12 
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C-193 

Correlation of Predictors with Outcomes (cross-sectional studies) 

(Sr) (B 12) (pmol/L) p (Sr) (folate) (pmol/L) p (Sr/CSF) (B vit) (unit) (S

Description of (Sub-) Groups 

N 

Mean SE/SD r= Mean SE/SD r= Mean SE/SD r= M

Male with dementia (Dx before 1995) 20 215 9.3 Male with intact cognition 83 313 10.8 Female with dementia (Dx before 1995) 

66 257 8.1 <0.005 

Female with intact cognition 173 297 10.5 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Human Studies 

C-194 

Correlation

Author, Year: Postiglione, 2001 Ref ID: 2583 Vitamins: Folate, B1

Objective: Correlate B vitamins to AD and MTHFR gene Study characteristics Population Controls Inclusion criteria Exclusion criteria 

Case-control Age: 68 Cases: Cases: Comparative %Male: 39% 

Study design 

Retrospective Race: nd 

AD, living at home, able to eat unaided 

Vascular dementia. Institutionalized or hospitalized in previous 3 mo. Vitamin supplementation, substances affecting homocysteine metabolism. 

Country: Italy Other: Controls: Controls: Setting: Memory 

clinic 

Funding: nd 

No dementia. MMSE>27. Mostly from among those who accompanied cases. 

Disease affecting homocysteine metabolism. 

Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population Plasma folate* ng/mL & nmol/L AD diagnosis N enrolled: 7Plasma B12** pg/mL & pmol/L N analyzed: 7C677T MTHFR mutation*** Drop-outs (%): Comments: * IMX system (Abbott). Normal range 3.1-12.4 ng/mL ** IMX system (Abbott). Normal range 179-1132 pg/mL *** PCR Other predictors/outcomes reported: Homocysteine Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Quality (A/B/C): B Applicability (1/2/3): Outcome(s): Results (Text) Interaction of B12 or Folate and MTHFR 

No significant differences in B12 or Folate levels by subcategories of cases or controls who were homoz

or non-homozygous 

Interaction of B12 and Folate with AD duration 

Statistically significant correlation between duration of disease (months) and plasma folates (r = –0.580, 

0.460, P<0.05). Thus a decrease in B vitamin levels with AD duration. 
Appendix C. Evidence Tables 

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C-195 

Correlation of Predictors with Outcomes (cross-sectional studies) 

Plasma B12 pmol/L p Plasma Folate nmol/L p Plasma B12 pmol/L p Plas

Description of (Sub-) Groups 

N 

Mean SD UNADJ Mean SD UNADJ Mean SD ADJ* Mea

AD 74 491 144 5.7 2.1 689 301 8.9 Healthy 74 780 211 <.001 8.5 3.2 <.001 701 234 NS 7.8 AD 74 4/74 (5%) < 179 pg/mL 15/74 (20%) < 3.1 ng/mL Healthy 74 0% nd 0% nd * Adjusted for age, serum creatinine, and duration of AD 
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B Vitamin Evidence Table – Human Studies 

C-196 

Correlation

Author, Year: Quadri, 2004 Ref ID: 2604 Vitamins: Folate, vit 

Objective: To examine the associations of plasma tHcy, sr folate, vit B12 concentration with mild cognitive impairment, AD, Va

the relationships between the biochemical variables and neuroradiologic mechanisms 

Study characteristics Population: AD Cog 

impaired

Controls Inclusion 

criteria 

Exclusion criteria D

XS Age: 79.1±7.7 76.1±7.1 75.6±8.5 Cases: Cases: NonComparative %Male: 34.3 40.7 38.2 

A

Study design 

Prospective Race: Probably 

100% W 

Probably 

100% W 

Probably 

100% W 

consecutive subjects from the memory clinic with dementia and Cog impaired 

Younger than 60 yr, with an isolated cognitive deficit, affected by dementias other than AD or VaD, or whose plasma tHcy conc not available, or those with vit B12 >600 pmol/L, folate >30 nmol/L or serum creatinine >180 μmol/L 

P

Country: Switzerland Other: 

Alcohol intake % >drinks/d 

0 1.2 1.8 Controls: Controls: V

Setting: Hospital 

clinic 

Education 7.9 ±2.5 9.1 ±3.6 9.9 ±3.8 O

Funding: ND 

elderly controls free of cognitive impairment 

ND 

Comments: NINCDS-ADRDA and CERAD: National Institute of Neurological and Communicative Disorders-Alzheimers Diseas

Association and of the Consortium to Establish a Registry for Alzheimers disease for possible AD 
Appendix C. Evidence Tables 

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C-197 

Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population oSerum vit B12* ND MMSE 0-30 N enrolled: 210 AD=74 Serum folate** ND Minimum medial temporal thickness mm N analyzed: 210 74 

Drop-outs (%): 0% 

Comments: * B12 measured with a radioimmunoassay kit with the use of 125I and for folate with 57Co: normal range not specified 

Other predictors/outcomes reported: Plasma tHcy 

Follow-up duration (if applicable): NA Reasons for drop out (if applicable): -- Limitations: Cross-sectional study; reference range for vitamins not availableQuality (A/B/C): B Applicability (1/2/3): Outcome(s): Results (Text) CT appearance of white matter lesions 

NS association with lower folate or vit B12 concentration in the demented group or in the whole sample 

Correlation of Predictors with Outcomes (cross-sectional studies) 

Sr folate nmol/L p Sr B12 pmol/L p CT scan Min medial temporal lobe thickness mm p Description of 

(Sub-) Groups 

N 

Mean SD r= Mean SD r= Mean SD r= 

AD 74 13.6 5.6 0.04 281 111 NS 12.2 2.6 NS CDR 0.5 81 14.0 5.9 0.04 275 117 NS 13.7 3.0 NS Control 55 16.9 5.8 278 99 14.5 1.9 

Among CDR 0.5 N A

Description of (Sub-) Groups 

N 

OR (Adj 1*) OR (Adj 2*) OR (Adj 1*) 

Vit B12 (Reference gp) >303 pmol/L 1 1 1 Vit B12 234-303 pmol/L 0.8 (0.3, 2.0) 0.8 0.3, 2.0 0.6 0.2, 1Vit B12 <234 pmol/L 

81 

1.0 (0.4, 2.4) 0.7 0.3, 1.8 

74 

0.8 0.3, 2

Sr folate (Reference gp) >19.5 nmol/L 81 1 1 74 1 
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C-198 

Sr folate 13.5-19.5 nmol/L 1.0 0.4, 2.8 0.9 0.3, 2.6 2.1 0.7, 6Sr folate <13.5 nmol/L 3.4 1.3, 8.7 3.1 1.2, 8.1 3.7 1.3, 10* Adj 1, adjusted for for age, gender, education and creatinine ... Adj 2*) age, gender, education and creatinine, Hcy, vit B12 and folate 
Appendix C. Evidence Tables 

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C-199 

Correlation

Author, Year: Ravaglia, 2000 Ref ID: 2642 Vitamins: B12, folat

Objective: To study the association between cognitive status and plasma tHcy levels in centenarians Study characteristics Population Controls Inclusion criteria Exclusion 

criteria 

Definition

XS Age: ~100 N/A Cases: Cases: Comparative %Male: 32 N/A 

AD: 

Study design 

Prospective Race: ND N/A 

Centenarian residents in 2 Provinces (Ravenna and Bologna), who underwent a standardized assessment for cognitive function, from Jan 1994 to Jan 1995 

Blood specimens not available 

PD: 

Country: Italy Other: Controls: Controls: VascDz: Setting: community Other: Funding: government 

N/A N/A 

Comments: 13 participants had no cognitive problem Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population B6 level AD N enrolled: 66 3B6 level Cognitively impaired-not demented N analyzed: ND 1B6 level Normal cognitive status Drop-outs (%): N/A 1Comments: B6 measured by HPLC (for pyridoxal-5’-phosphate: active coenzyme form of B6); lower reference value fOther predictors/outcomes reported: serum Cre; serum folate; serum B12; plasma tHcy Follow-up duration (if applicable): N/AReasons for drop out (if applicable): N/ALimitations: power calculations not measured; results not reported Quality (A/B/C): C Applicability (1/2/3): 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Human Studies 

C-200 

Outcome(s): Results (Text) B6 deficiency B6 deficiency was present in 85% of normal centenarians, 50% of cognitively impaired not-demented, and 64.7

VascDz patients 40% had B6 deficiency; Among the 3 patients with other dementia (PD, alcoholism, and hypodeficiency 

Cognitive status (AD, Cognitively impaired-not demented, Normal) 

NS difference among the groups was found for B6 (ANOVA followed by multiple comparisons Tukey test, F:0

Correlation of Predictors with Outcomes (cross-sectional studies) 

(Sr) (B 6) (nmol/L) p (Sr/CSF) (B vit) (unit) p (Sr/CSF) (B vit) (unit) (S

Description of (Sub-) Groups 

N 

Mean SE/SD r= Mean SE/SD r= Mean SE/SD r= M

AD 34 9.8 Cognitively impaired-not demented 10 11.9 Normal cognitive status 13 8.1 B6 measured by HPLC (for pyridoxal-5’-phosphate: active coenzyme form of B6); lower reference value for plasma B6: 11.7 nmol/L 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Human Studies 

C-201 

Correlation

Author, Year: Ravaglia, 2003 Ref ID: 2644 Vitamins: Folate, B1

Objective: 

Study characteristics Population Controls Inclusion criteria Exclusion criteria 

XS Age: 

MMSE  24-25  26-28  >28 

78.6 73.1 71.8 

NA Cases: All 

residents of Conselice Municipality (Ravenna Province), ≥65yr, MMSE ≥ 24

Cases: medical condition or drug tx affectinconcentrations: hx AMI, stroke/transient iscattacks, liver disease, reduced renal excreticancer, vitamin tx, theophylline tx, psychotrdrugs, cytotoxic drugs, HRT; cognitive impaepilepsy, psychiatric illness, sensory-motor impairments affecting neuropsychological teclock drawing test score ≤ 6, one or more A

Comparative %Male: 45 NA 

Study design 

Prospective Race: ND NA 

Country: Italy Other: Controls: Controls: Setting: Community Funding: Government Comments: Subjects had clinical exam, MMSE, & interview for lifestyle, medication use, medical history, sociodemographic, diet

Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population o

Serum folate* MMSE 30 pt Italian version N enrolled: 650 Serum vitamin B12* MMSE 30 pt Italian version N analyzed: 650 

Drop-outs (%): NA 

Comments: 

*Immunoelectrochemiluminescence analysis – Elecsys Folate Immunoassay & Elecsys B12 Immunoassay for Elecsys 2010 System; lonmol/L for serum folate and 148 pmol/L vit B12 Other predictors/outcomes reported: 

Predictor serum creatinine significantly higher in MMSE score 24-25 than score >28, Plasma 

in group with MMSE 26-28 than MMSE > 28 & group MMSE 24-25 higher than MMSE 26-28; physical activity to increase MMSE scores 

Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Quality (A/B/C): C Applicability (1/2/3): 
Appendix C. Evidence Tables 

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C-202 

Correlation of Predictors with Outcomes (cross-sectional studies) 

Sr B 12 (unit) p Sr Folate 

Description of (Sub-) Groups 

N Mean 95%CI r= Mean 95% CI 

MMSE 24-25 46 233 206 – 264 NA 11.4 10.0 – 13.0 MMSE 26-28 259 240 228 – 253 11.3 10.7 – 11.9 MMSE >28 345 237 227 – 248 

NS 

11.6 11.1 – 12.2 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Human Studies 

C-203 

Correlation

Author, Year: Ravaglia, 2004 Ref ID: 2646 Vitamins: B12, folat

Objective: To study the association between specific cognitive skills and plasma tHcy levels in healthy and cognitively normal el

and to analyze several potential confounders of tHcy levels 

Study characteristics Population Controls Inclusion 

criteria 

Exclusion criteria 

Cohort Age: 72.9 +/-SD 

8.2 Range 

65-91yr 

N/A Cases: Cases: 

Non-comparative %Male: 53 N/A 

Study design 

Retrospective Race: ND N/A 

All residents of Conselice Municipality (Ravenna Province), aged ≥65yr 

Institutionalization; major sensory deficits; epilepsy; major psychiatric illness; infections of the brain; surgical intervebtion for brain tumor or aneurisms; mental retardation; significant developmental learning disorders; focal brain lesions; alcoholism; head trauma with loss of consciousness >1h; GDS ≥20; dementia; 

loss of dependence in IADL due to cognitive impairment; Hx acute MI, stroke or TIA; current liver disease; reduced renal excretion (Cre serum>133μmole/L); cancer; DM; Tx with Vit, theophylline, psychotropic drugs, cytotoxic drugs, and ERT 

Country: Italy Other: Education, 

yr: 4.3 +/-

SD 1.5 

Controls: Controls: 

Setting: community Funding: ND 

N/A N/A 

Comments: Included participants were all non-demented healthy elderly people 
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Predictor(s): (eg, B vit level) 

Outcome(s): Definition: Total 

B6 Mental 

Deterioration Battery (MDB) 

7 parts that provide info for different areas of cognition: Reye’s 15 word immediate and delayed recall for verbal memory, phonemic word fluency and sentence construction for language, Raven’s progressive matrices ’47 for logical reasoning, immediate visual memory for visual memory, freehand copying of drawings and landmarks for constructional praxis 

N enrolled: 

62 

 Prose memory 

test, IGNSA 1987 

N analyzed: 

ND 

 Corsi block 

tapping test, IGNSA 1987 

Evaluation of short-term spatial memory Drop-outs 

(%): 

N/A 

 MMSE Italian version Comments: B6 measured by HPLC (for pyridoxal-5’-phasphate: active coenzyme form of B6) Other predictors/outcomes reported: age; years of education; serum Cre; serum folate; serum B12; plasma tHcyFollow-up duration (if applicable): N/A Reasons for drop out (if applicable): N/A Limitations: non-controlled study; power calculations not measured; results not reportedQuality (A/B/C): C Applicability 

(1/2/3): 

1 (healthy elderly wcommunity in Italy

Outcome(s): Results (Text) Neuropsycologiacal measures 

NS association between B6 levels and neuropsycologiacal measures (specific results not given) 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Human Studies 

C-205 

Correlation

Author, Year: Refsum, 2003 Ref ID: 2661 Vitamins: B12 

Objective: Evaluation of holotranscobalamin in cognitively impaired Study characteristics Population Controls Inclusion criteria Exclusion 

criteria 

XS Age: 75.2 

(72.8-77.7) 

70.5 

(68.4-72.7) 

Cases: 

Comparative %Male: 43% 32% 

Study design 

Retrospective Race: nd nd 

Cases: Varying degrees of cognitive dysfunction, referred to Oxford Project to Investigate Memory and Ageing. Histologically confirmed at autopsy. Serum available for retesting

Age <55 y, no blood sample available (origincriteria) 

Country: UK CAMCOG: 39.3 

(33.9-44.8) 

100.4 

(95.6-105.2) 

Controls: Controls: 

Setting: Clinic MMSE 11.4 

(9.8-13.0) 

28.9 

(27.5-30.3) 

Funding: Pharmaceutical 

Elderly volunteer controls without symptoms of memory impairment (some of whom were patients’ relatives). Serum available for retesting 

Comments: SUBSET OF CLARKE 1998 REF ID 622. Later re-evaluation of same subjects. CAMCOG, Cambridge Cognitive Examination, maximum score 107 MMSE, Mini-Mental Status Examination, maximum score 30 Predictor(s): (eg, B vit level) Outcome(s): Definition: Total PopulatioHolotranscobalamin (holoTC)* pmol/L AD diagnosis N enrolled: 116  metabolically active fraction of plasma cobalamins N analyzed: 116 

Drop-outs (%):

Comments: * Axis-Shield, solid phase RIA. Normal range determined as part of study. Other predictors/outcomes reported: Serum cobalamin (total), (Serum folate: see Clarke 622) Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Quality (A/B/C): C Applicability (1/2/3): 
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Outcome(s): Results (Text) Correlation of Predictors with Outcomes (cross-sectional studies) 

Serum HoloTC (pmol/L) p 

Description of (Sub-) Groups 

N 

Geometric Mean Range r= 

AD (histology) 51 41.1 (36.1-46.8) <0.001 Controls 65 57.1 (51.1-64.1) ALL OR (Adj 1*) OR (Adj 2*) Low holoTC (<40 pmol/L) 116 3.40 (1.45-7.97) 2.82 (1.02-7.83) HIGH Hcy (>14 μmol/L) Low holoTC (<40 pmol/L) ~58 9.45 (2.31-38.7) LOW Hcy (<14 μmol/L) Low holoTC (<40 pmol/L) ~58 0.91 (0.15-5.31) * Adj 1, adjusted for age and sex, and total cobalamin, MMA, Hcy, and Folate; Adj 2, adjusted for age, sex, smoking, social class, and 

cobalamin, MMA, Hcy, and Folate. 
Appendix C. Evidence Tables 

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C-207 

Correlation

Author, Year: Regland, 1988 Ref ID: 2663 Vitamins: B12, folat

Objective: Study characteristics Population Controls Inclusion criteria Exclu

criteri

XS Age: 

AD Senile dementia 

59 75 

72 Cases: Cases

Comparative %Male: ND ND 

Study design 

Retrospective Race: ND ND 

Hospital geropsychiatric unit dementia patients 

Country: Sweden Other: Controls: ControSetting: Inpatient 

geropsychiatric unit 

Funding: Government grant & private foundations 

Hospital geropsychiatric unit dementia patients diagnosed with vascular dementia 

Comments: 66 yr cut-point for AD vs senile dementia of AD type Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population of Serum B12 pmol/l Dementia DSM-III criteria N enrolled: 145 91 Blood folate nmol/l N analyzed: 145 91 Plasma folate nmol/l Drop-outs (%): Comments: Medication and nutrition history unavailable for analysesIsotope dilution assay Reference limit for blood folate 90-450 nmol/l Other predictors/outcomes reported: Stratification of total group by serum B12 levels at 200 pmol/l resulted in patients with low B12 were older and blood folate was lower than normal B12 level; negative correlation between serum B12 levels and platelet MAO activity (r = -0.33, p < 0.002), negative correlation for HVA and vitamin B12 (r = -0.23, p < 0.02) Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Quality (A/B/C): 
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C-208 

Correlation of Predictors with Outcomes (cross-sectional studies) 

Description Serum B12 (unit) p Plasma Folate (unit) p Blood Folate (unit) p of (Sub-) Groups 

N 

Mean SD r= Mean SD r= Mean SD r= 

Control 54 335 184 13 8 277 144 AD 35 319 132 11 4 262 77 Senile dementia 56 246 158 

0.0002 

12 5 

NS 

244 84 

NS 

Serum vitamin B12: Control > Senile dementia, AD > Senile dementia Mean vitamin B12 concentrations levels for control & AD groups were normal vs low concentration for senile dementia grou
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Correlation

Author, Year: Religa, 2003 Ref ID: 2678 Vitamins: B12, folat

Objective: To examine the relationship between plasma Hcy levels and vit status and to identify the genetic status of the ApoE an

polymorphism in Polish AD, mild cognitive impairment and age matched controls 

Study characteristics Population AD MCI Controls Inclusion 

criteria 

Exclusion criteria 

Definitions 

XS Age: 74.2(6.3) 70.7(7.0) 71.2 (6) Cases: Cases: Comparative %Male: ND ND ND 

AD: M

NprD

Study design 

Prospective Race: ND ND ND 

AD patients from the Alzheimer day clinic by examination clinical and radiological 

PD: 

Country: Poland Other: Controls: Controls: VascDz: Setting: Academic 

medical 

Other: 

Funding: Gov and Foreign grants 

MCI patients from the clinic and examined by a panel of specialists and neurologists 

Cognitively intact patients from surgical and medical wards or spouses of AD patients 

Mildly cognitive impaired 

Cscd3 msed

Comments: Cognitively intact healthy adults based on MMSE score MMSE: 29(+/-1) normal Predictor(s): (eg, B vit level) 

Outcome(s): Definition: Total Popu

int

Folic acid 5.3-14.4 

ng/ml 

Classification of study population based on clinical dementia rating score and other clinical symptoms and MMSE 

MMSE: 29(+/-1) normal 

N enrolled: 297 

Vit B12 157-1059 

pg/mL 

N analyzed: 297 Drop-outs (%): na 

Comments: Folate by AxSYM folate reagent assay and vit B12 by immunoassay; Normal ranges in the table Other predictors/outcomes reported: MTHFR gene polymorphism; ApoE; homocysteine 
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Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: No adjustment of cross-sectional data Quality (A/B/C): C Applicability (1/2/3): Outcome(s): Results (Text) tHcy The mean plasma tHCy levels were sig higher in patients with AD (18.03±10.8) than in controls (14.43±4.48;p

(14.15±4.09; p<0.0001). 

Apo E 4 allele The distribution of ApoE4 allele was sig higher in the AD population (p<0.0001) than in controls and MCI (p<Correlation of Predictors with Outcomes (cross-sectional studies) 

Sr Folate ng/ml p Sr B12 pg/mL p 

Description of (Sub-) Groups 

N 

Mean SD r= Mean SD r= 

Probable AD 99 8.5 3.38 NA NS 316.7 139.5 <0.05* Mild cognitive impaired (MCI) 98 10.87 3.93 ND NS 386.3 158.7 NS Cognitive intact Healthy elderly 100 7.56 5.39 413.5 241.3 * Compared to Cognitive intact healthy elderly 
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Correlation

Author, Year: Robins Wahlin, 2001 Ref ID: 2741 Vitamins: B12, folatObjective: To provide further evidence of the presence and extent of vitamin-related effects on cognitive performance in old age Study characteristics Population Controls Inclusion criteria Exclusion criteria 

XS Age: 85.5 (5) 83.9 ( Cases: Cases: Comparative %Male: 18% 21% 

Study design 

Prospective Race: Probably 

white 

100% 

Probably 

white 

100% 

All 75 yrs and above, and residents living in the Kungsholmen parish in Stockholm, Sweden and were assessed in 2 phases for inclusion. A random sample of those with an MMSE score above 23 were assessed in phase 2 with extensive examinations

All demented subjects, psychiatrpatients or with psychiatric diagnosis, visual disabilities, not screened for vit B12, folate statuon vitamin supplement meds, anthose who did not complete the cognitive tests. Subjects with intof anticonvulsants, antimetabolites, and trimethoprim another anti-folate meds

Country: Sweden Other: Controls: Controls: Setting: Community Funding: Gov, private, non-industry (multiple sources) 

Same as above, the controls were selected from those with normal B12 and folate 

Same as above 

Comments: Subjects were grouped into vitB12 and/or Folate deficient and controls were both vit B12 and folate normal 
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Predictor(s): (eg, B vit level) 

Outcome(s): Definition: Total 

Vit B12 blood level 

200 pmol/L 

Clock setting and reading 

Drawing and reading clock times with clock faces with marks at number location and no numbers marked 

N enrolled: 

230 

Folate blood level 

11 nmol/L 

N analyzed: 

Trail making test 230 A and B, accuracy Trail making test A and B, time 

A shortened version of the TMT from the Halstead Reitan Battery; part A had a max score of 12 and part B had a max score of 11. Accuracy and number of seconds needed to finish each part were registered with unlimited performance 

time 

Drop-outs (%): 

0% 

 Digit span 

forward and backward 

Administered using WAIS-R criteria 

 Verbal fluency 

tests 

Comments: Analyzed with ANOVA and regression analysis 

Vit B12 and folate assessed using radioimmunoassay method with cut-offs 200 pmol/L and 11 nmol/L respectively 

Other predictors/outcomes reported: MMSE Follow-up duration (if applicable): NA Reasons for drop out (if applicable): NA Limitations: Quality (A/B/C): B Applicability (1/2/3): 
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Outcome(s): Results (Text) Clock test No significant main or interaction effects Block design* Main effects of B12, F (1,226)=5.33, MSE=40.96, P<0.05, ω2=0.02; groups with lower levels of vit B 12 perfo

groups with normal vitamin levels Main effects of folate, F (1,226)=24.85, MSE=40.96, P<0.0005, ω2=008; groups with lower of vit folate perfor

groups with normal vitamin levels Significant association between B12 and Block design performance (paced: beta=0.19; P<0.01; self-paced: beta

Trail making test A No reliable effects either accuracy or time Trail making test B Significant main effects of FA on accuracy, F (1,226)=9.13, MSE=7.07, P<0.01, ω2=0.03 

Significant main effects of FA on time, F (1,226)=7.68, MSE=11 114.19, P<0.01, ω2=0.03 

The low folate values were associated with lower performance The effect of B12 and the interaction effect were not significant 

Digit span forward* No reliable or interaction effects Digit span backward* 

Significant main effects of FA on accuracy, F (1,226)=8.47, MSE=1.05, P<0.01, ω2=0.03 

The low folate values were associated with lower performance The effect of B12 and the interaction effect were not significant 

Verbal fluency test Significant effects for both B12 P<0.01and folate P<0.05 * Part of Wechsler Adult Intelligence Scale Correlation of Predictors with Outcomes (cross-sectional studies) 

N B12/N folate p N L B12/N folate p N B12/L Folate P 

Description of (Sub-) Groups 

N 

Mean SD Mean SD Mean SD M

MMSE 126 27.46 2.22 Nd 26.5 2.76 nd 26.26 2.26 nd 2
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Correlation

Author, Year: Scileppi, 1984 Ref ID: 10016 Vitamins: B1, B2, B

Objective: Compare vitamin levels in AD v non-AD Study characteristics Population Controls Inclusion criteria Exclu

criter

XS Age: nd Cases: CasesComparative %Male: nd 

Study design 

Prospective Race: nd 

Series of subjects coming to a subspecialty dementia clinic in a prosperous suburb. Diagnosed with AD. 

Country: US Other: Controls: ContrSetting: Dementia 

clinic 

Funding: Industry, Non-Profit 

Same as cases, except diagnosed with condition other than AD (implied only). Controls = Normal (intellectually intact, n=10), Multi-infarct dementia (n=28), Other dementias (n=8), and Depression (n=12) 

Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population of Blood B1* ng/mL Dx of AD v Control nd N enrolled: 113 55 Blood B2** ng/mL Blood B6*** ng/mL Blood B12  pg/mL 

N analyzed: 54-55 

Blood folate** *** ng/mL Drop-outs (%): Comments: * Analyzed protozoologically. Lower level of normal = 25 ng/mL ** Analyzed protozoologically. Lower level of normal = 110 ng/mL *** Analyzed protozoologically. Lower level of normal = 29 ng/mL   Analyzed protozoologically. Lower level of normal = 105 pg/mL ** *** Analyzed with Lactobacillus casei. Lower level of normal = 5.0 ng/mL Other predictors/outcomes reported: Other vitamins Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Very limited reporting Quality (A/B/C): C Applicability (1/2/3): 
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Outcome(s): Results (Text) Correlation of Predictors with Outcomes (cross-sectional studies) 

Bl B1 ng/mL Bl B2 ng/mL Bl B6 ng/mL Bl B12 pg/mL 

Description of (Sub-) Groups 

N 

Mean SEM P 

N 

Mean SEM P 

N

Mean SEM P 

N

Mean SEM P 

AD 55 46 4 55 295 10 54 44.9 6.3 55 290 31 Control (non-AD) 58 48 4 NS 58 292 9 NS 58 38.2 2.4 NS 58 533 25 NS Univariate analyses. No explanation for large difference in B12, with relatively small SEM, but NS difference. 
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Correlation

Author, Year: Serot, 2001 Ref ID: 2933 Vitamins: B6, B12, F

Objective: Evaluation of choroids plexus dysfunction, thus folate levels Study characteristics Population Controls Inclusion criteria Exclusio

criteria 

XS Age: 75.9+/-

6.6 

I. 40.6+/-11.3 II. 72.7+/-7.0 

Cases: 

Noncomparative %Male: 37% I. 52% II. 28% 

Study design 

Retrospective Race: nd nd 

Cases: All CSF samples obtained by lumbar puncture, performed to rule out such neurological diseases as CNS infection, subarachnoid hemorrhage, or for diagnostic myelography. Samples contained <0.06 g/L protein and <3 cells/mL. By review or medical records, divided into 3 groups:  III. AD, >60 y 

Country: France Other: Controls: Setting: Mixed Funding: Government, Non-profit 

Controls:  I. Normal mentally healthy adults 20-60 y  II. Normal, mentally healthy elderly >60 y

Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population of iCSF Folate* ng/mL AD v non-AD N enrolled: 126 30 Serum Folate* ng/mL MMSE N analyzed: 126 30 

N analyzed (serum): 30 

Comments: * Sanofi Diagnostics Pasteur: Access Immunoassay System. ND on normal values. Other predictors/outcomes reported: Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Quality (A/B/C): C Applicability (1/2/3): 2 Outcome(s): Results (Text) MMSE In group III (AD), CSF-folate levels varied with the severity of dementia with a “slight correlation” (r=0.35) 
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Correlation of Predictors with Outcomes (cross-sectional studies) 

CSF Folate ng/mL p N Serum Folate ng/mL p 

Description of (Sub-) Groups 

N 

Mean SD r= Mean SD r= 

AD (III) 30 8.26 1.82 <0.001 30 5.35 2.15 NS Healthy young (I) 60 10.47 1.93 24 5.31 1.73 Healthy elderly (II) 36 9.96 2.01 NS 28 5.81 2.13 
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Correlation

Author, Year: Seshadri, 2002 Ref ID: 2936 Vitamins: B12, folat

Objective: To examine the relation between plasma tHcy levels and newly diagnosed AD in elderly population-based cohort Study characteristics Population Controls Inclusion criteria Exclusion 

criteria 

Definitions 

Longitudinal Age: 76 ± 6 

(range 

68-97) 

N/A Cases: Cases: 

Non-comparative %Male: 39 N/A 

Study design AD: 

Prospective Race: ND N/A 

Subjects enrolled in a dementia-free cohort between 1976-78, who underwent their 20th biennial examination 

between 1986-90 and had Hcy levels measured 

ND 

PD: 

Country: US Other: Controls: Controls: VascDz: 11 Setting: community Other: 

Non-AD degenerative dementia: 11other types:6

Funding: government 

N/A N/A 

Comments: Framingham Study participants Predictor(s): (eg, B vit level) 

Outcome(s): Definition: Total Population of int

B12, Folate, B6 Dementia N enrolled: 1092 111 B12, Folate, B6 AD N analyzed: 1092 83 

Drop-outs (%): 0 0 

Comments: Of the total population N=1092, 85% had measurements for B12, 92% for B6, and 98% for folate; not reported ho

with B12, B6, and folate measurements developed dementia and/ or AD Plasma folate was measured by amicrobial (Lactobacillus casei) assay with a 96-well plate and manganese supple

Plasma B12 levels were estimated with the use of a radioassay kit (Magic, Ciba-Corning, Medfield, Mass) B6 (PLP) was measured by the tyrosine decarboxylase apoenzyme method (REF 32) Coefficients of variation for these assays were 13% for plasma folate, 7% for B12, and 16% for PLP 

Other predictors/outcomes reported: Age, gender, APOE genotype, Hcy levels, education level, cigarette smoking, alcohol intak
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Follow-up duration (if applicable): Median 8 yr (range 1-13) Reasons for drop out (if applicable): Limitations: Race info not given; results for B12, B6, and folate and their relation to AD /dementia not rQuality (A/B/C): B Applicability (1/2/3): 3 Outcome(s): Results (Text) Dementia, AD After adjusting for age, sex, and APOE genotype none of the Vit levels (B12, folate, B6) were independently re

dementia or AD 
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Correlation 

Author, Year: Shahar, 2001 Ref ID: 2940 Vitamins: Vit B12 

Objective: To determine the prevalence of low and low normal vitamin B12 levels in “sick” elderly subjects hospitalized in a ger

analyzed the relationship of vitamin B12 levels to several clinical parameters 

Study characteristics Population* Controls Inclusion criteria Exclus

criteria 

XS Age: 78 (8) Cases: Cases: Non-comparative %Male: 46% 

Study design 

Retrospective Race: Probably 

white 

Patients of either gender who were ≥65 yrs old and were discharged from the hospital or died in the hospital between Jan 1 and Dec 31 1996 and included those who had sr vit B12 analyzed once during hospital stay and whose last name commenced with one of the first 12 

letters of the Hebrew alphabet 

As inclucriteria 

Country: Israel Other: Controls: ControlSetting: Academic 

hospital 

Inhospital death 

38.3% 

males and 

35.9% for 

females 

Funding: ND 

None 

Comments: Though comparative in the study none of the comparative groups were eligible as controls for this data extraction * Data available for men and women separately Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Populatio

(cog im

Vitamin B12 levels-low <150 pmol/L Cognitive impairment ND N enrolled: 640 37Vitamin B12 levels-borderline 150-250 pmol/L N analyzed: 640 37Vitamin B12 levels-normal >250 pmol/L Drop-outs (%): 0 Comments: Sr B12 measured by “access” immunoassay system 
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Other predictors/outcomes reported: 

Folic acid levels correlating with vit B12 levels (not data extracted as no separate subgroup ana

for vitamin deficiency 

Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Poor sampling; no definition of cognitive impairment; Quality (A/B/C): C Applicability (1/2/3): Outcome(s): Results (Text) Correlation of Predictors with Outcomes (cross-sectional studies)-Among cognitive impaired only for this study 

Sr B 12 vit pmol/L 

Description of (Sub-) Groups Cognitive impairment

N 

Mean SE/SD % 

Low B12 <150 pmol/L 46.9% Borderline B12 150 to 250 36.4% Normal >250 35.7% Total cognitive impaired 238 U
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Correlation

Author, Year: Snowdon, 2000 Ref ID: 3059 Vitamins: Folate 

Objective: To investigate the relation between serum folate and the severity of atrophy of the neocortex at autopsy; to investiaget 

have a strong association with atrophy of the nerocortex with an atrophic disease process like AD. 

Study characteristics Population Controls Inclusion criteria Exclusion 

criteria 

Definitions 

XS Age: 91 y 

(died) 

Cases: Cases: 

Comparative %Male: 0 

AD: Neuro

neuroplaqumm2 

Study design 

Retrospective Race: white 

30 nuns who died 2 to 55 mo (average 24 mo) after serum folate measurements were taken. 

PD: 

Country: US Other: Controls: Controls: VascDz:Setting: convent Other: Funding: National Institute on Aging, Abercrombie 

Foundation & the Kleberg Foundation 

65 survivors 

Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total PoFolate Neocortex 

Atrophy 

N enrolled: 30 

Vitamin B-12 Number of AD 

lesions 

N analyzed: 30 

Vitamin B-6 Drop-outs 

(%): 

0 

Thiamine Comments: only histopathological diagnoses of AD reported in this study; no clinical correlation Other predictors/outcomes reported: Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Quality (A/B/C): B Applicability (1/2/3): 3 
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Outcome(s): Results (Text)  Among all 30 participants, the age-adjusted correlation of serum folate with the severity of atrophy was –0.40 ( Among the subset of 15 subjects with significant number of AD lesions, the age-adjusted correlation between f

atrophy was −0.80 (p=0.0006). None of the other nutrients were significantly correlated with the severity of atr

 The severity of atrophy of the neocortex was significantly correlated with the mean number of neurofibrillary ta

with signficant number of AD lesions (r=0.54, p=0.048). Serum folate was not significantly correlated with the 

neurofibrillary tangles in the neocortex (r= −0.14, p=0.63). 

 Regression analyses for the subset of 12 subjects indicated that folate had a signficant inverse association with 

adjustment for age and the number of neurofibrillary tangles: a 10-nmol/L decrease in serum folate was associadecrease in the score for the MMSE (p=0.04). 

Correlation of Predictors with Outcomes (cross-sectional studies) 

Sr folate nmol/L p Sr B- 12 nmol/L p Sr B-6 nmol/L Sr 

Description of (Sub-) Groups 

N 

Mean SD r= Mean SD r= Mean SD r= Mean 

(+) Significant number of AD lesions 15 45 52 −0.80 <0.001 119 58 -.19 NS 319 189 −0.38 NS 142 Without signficant number of AD lesions 15 61 54 .14 NS 128 94 -.08 NS 290 65 .03 NS 148 
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Correlation

Author, Year: Stewart, 2002 Ref ID: 3133 Vitamins: Plasma ho

Objective: To investigate the association between homocysteine concentrations and cognitive impairment in an older African-CarStudy characteristics Population Controls Inclusion criteria Exc

crite

XS Age: 65 (n=238?) Cases: CasComparative %Male: 47% (n=238?) 

Study design 

Retrospective Race: African/Caribbean 

descent 

248 participants with plasma homocysteine data and born in a Caribbean nation 

Country: UK Other: Controls: ConSetting: Primary care 

services 

Funding: Wellcome Trust Comments: Discrepancy between n=238 in table 1 and text description of n=248 Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Highest quartile of homocysteine concentration (>13.85 micromol/L) Cognitive 

impairment 

Yes or No N 

enrolled: 

248 

N analyzed: 

248 

Drop-outs (%): 

Comments: 11 psychometric tests drawn from the Consortium to Establish a Registry for Alzheimer’s Disease and WHO batteries; subjects were categorized as having relative cognitive impairment on the basis of scores <30%tile on 6 or more tests, or <10%tile on 4 or more tests. Other predictors/outcomes reported: Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Quality (A/B/C): B Applicability (1/2/3): 2 Outcome(s): Results (Text) 
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C-225 

 Cognitive impairment was classified in 68 (27%) participants. Raised homocysteine (highest quartile: >13.85 m

associated with cognitive impairment (OR=2.50, 95% CI = 1.33 to 4.69). This association persisted after adjust

other measures of vascular risk, folate, BMI and waist:hip ratio (OR=3.00, 95% CI = 1.35 to 6.69). As with othdisease in this sample, the association was significant only in those with less education (p-value for interaction=

was independent of other measures of vascular risk and was not explained by folate concentrations. 

Cognitive impairment 

Description of (Sub-) Groups 

N 

OR 

OR (Adjusted for 

age, occupation, 

other measures of 

vascular risk, 

folate, BMI and 

waist:hip ratio ) 

Homocysteine ≤ 13.85 micromol/L 180 (?) Homocysteine >13.85 micromol/L 68 

OR=2.50, 

95% CI = 

1.33 to 4.69 

OR=3.00, 

95% CI = 

1.35 to 6.69 
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Correlation

Author, Year: Stuerenburg, 2004 Ref ID: 3150 Vitamins: B12 

Objective: To investigate the correlation between plasma B12 levels and cognitive impairment in AD patients Study characteristics Population Controls Inclusion 

criteria 

Exclusion criteria 

Definitions 

XS Age: 71.8 ±SD 

8.5 

N/A Cases: Cases: 

Comparative %Male: 45 N/A 

AD: NINCD

6)

Study design 

Retrospective Race: 

Patients with AD ND 

PD: 

Country: Germany Other: Controls: Controls: VascDz:Setting: ND Other: Funding: ND 

N/A N/A 

Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population B12 MMSE score ND N enrolled: ND ND B12 Lower percentile (<184ng/mL) MMSE score ND N analyzed: ND ND B12 Upper percentile (>598ng/mL) MMSE score ND Drop-outs (%): N/A Comments: Other predictors/outcomes reported: age Follow-up duration (if applicable): N/A Reasons for drop out (if applicable): N/A Limitations: sample not well-described; methods of evaluation (B12, MMSE) not described; res

reported; confounding factors also not considered (except for age)

Quality (A/B/C): C Applicability (1/2/3): Outcome(s): Results (Text) MMSE scores NS correlation between plasma B12 and MMSE scores. A significant inverse correlation became apparent whe

those patients with the lowest 10% B12 plasma levels were compared with the upper B12 plasma levels (Spearm
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Correlation of Predictors with Outcomes (cross-sectional studies) 

(Sr) (B 12) (ng/mL) p (Sr/CSF) (B vit) (unit) p (Sr/CSF) (B vit) (unit) (S

Description of (Sub-) Groups 

N 

Mean SE/SD r= Mean SE/SD r= Mean SE/SD r= M

All subjects (B12 compared to MMSE scores); Spearman rank correlation 

241 371 216 ND 0.38 

Subjects with B12<184ng/mL ND 15.7 6.1 Subjects with B12>598ng/mL ND 20 4.6 

-0.36 0.008 
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Correlation

Author, Year: Teunissen, 2003 Ref ID: 3239 Vitamins: B12, folat

Objective: To investigate whether elevated serum tHcy is a risk factor for cognitive decline Study characteristics Population Controls Inclusion criteria Exclusion criteria 

Longitudinal Age: 57 

± 

11 

N/A Cases: Cases: 

Non-comparative %Male: 59 N/A 

Study design 

Prospective Race: 

Normal aging subjects of MAAS (Maastricht Aging Study) were randomly drawn from the Registration Network Family Practices; baseline medical and neuropsychological examination in 1993; 

Evidence of past or present that may compromise brain such as cerebrovascular dise(including stroke), chronic neurological pathology (e.gdementia, epilepsy or PD), mretardation or chronic psychdrug use 

Country: The Netherlands Other: Controls: Controls: Setting: community Funding: Non-profit 

N/A N/A 

Comments: For a number of participants (those who did not have available serum sample at baseline) age and gender are not reporPredictor(s): (eg, B vit level) Outcome(s): Definition: Total PB12, folate Patients with 

available B12, folate at baseline 

World Learning Test (WLT); Delayed Recall Test 

Based upon the Auditory Verbal Learning Test (REF 35); evaluates the ability to acquire and retain verbal info. 

N enrolled: 93 

B12, folate Patients with 

available B12, folate at baseline 

Letter-Digit Coding Test (LDCT) 

Paper-and-pencil test is a modified version of the Symbol Digit Modalities Test (REF 36) and measures info processing speed. 

N analyzed: 

92 

B12, folate Patients with 

available B12 at baseline 

STROOP Color-Word Test 

Subtask III involves color names but the printing ink is different from the color name. Only the data of subtask III are used in the current study 

Drop-outs (%): 

1 

Comments: B12, folate were measured using commercial kits (Bayer Immuno 1, Leverkusen, Germany) 
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Predictor(s): (eg, B vit level) Outcome(s): Definition: Total B12 Patients with 

available B12 either at baseline or during followup 

World Learning Test (WLT); Delayed Recall Test 

Based upon the Auditory Verbal Learning Test (REF 35); evaluates the ability to acquire and retain verbal info. 

N enrolled: 

115 

B12 Patients with 

available B12 either at baseline or during followup 

Letter-Digit Coding Test (LDCT) 

Paper-and-pencil test is a modified version of the Symbol Digit Modalities Test (REF 36) and measures info processing speed. 

N analyzed: 

114 

B12 Patients with 

available B12 either at baseline or during followup 

STROOP ColorWord Test Subtask III involves color names but the printing ink is different from the color name. 

This test shows robust effects of chronological age (REF 37). Only the data of subtask III are used in the current study 

Drop-outs (%): 

1 

Comments: B12 were measured using commercial kits (Bayer Immuno 1, Leverkusen, Germany) Predictor(s): (eg, B vit level) Outcome(s): Definition: Total folate Patients with 

available folate either at baseline or during followup 

World Learning Test (WLT); Delayed Recall Test 

Based upon the Auditory Verbal Learning Test (REF 35); evaluates the ability to acquire and retain verbal info. 

N enrolled: 

115 

folate Patients with 

available folate either at baseline or during followup 

Letter-Digit Coding Test (LDCT) 

Paper-and-pencil test is a modified version of the Symbol Digit Modalities Test (REF 36) and measures info processing speed. 

N analyzed: 

111 

folate Patients with 

available folate either at baseline or during followup 

STROOP ColorWord Test Subtask III involves color names but the printing ink is different from the color name. 

This test shows robust effects of chronological age (REF 37). Only the data of subtask III are used in the current study 

Drop-outs (%): 

4 

Comments: Folate was measured using commercial kits (Bayer Immuno 1, Leverkusen, Germany) 
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Other predictors/outcomes reported: Hcy, age, gender, level of eduaction Follow-up duration (if applicable): 6 yrReasons for drop out (if applicable): insufficient serum measurementsLimitations: Part of the population not described (age, gender); power calculations not reported Quality (A/B/C): B Applicability (1/2/3): Outcome(s): Results (Text) World Learning Test (WLT); Delayed Recall Test 

Based upon the Auditory Verbal Learning Test (REF 35); evaluates the ability to acquire and retain verbal info

correctly reproduced words on the 5 immediate recall trials is recorded (WLTTOT). After 20 min the subject is of words (Delayed Recall) (REF 31). Higher score reflects better cognitive performance 

Letter-Digit Coding Test (LDCT) 

Paper-and-pencil test is a modified version of the Symbol Digit Modalities Test (REF 36) and measures info pr

number of correctly copied corresponding numbers in 90 sec is recorded as test outcome. Higher score reflects performance 

STROOP ColorWord Test The test examines the speed at which color names are read (subtask I) and the speed at which color spots are na

III involves color names but the printing ink is different from the color name. The time needed to name the colowords is recorded. Lower score reflects better cognitive performance. This test shows robust effects of chronolo

the data of subtask III are used in the current study 

Correlation of Predictors with Outcomes (zero order correlation, Spearman correlation coefficients) STROOP test 

(Sr) (B 12) (ng/L) p (Sr) (folate) (mg/L) p (Sr/CSF) (B vit) (unit) (S

Description of (Sub-) Groups 

N 

Mean SE/SD r= Mean SE/SD r= Mean SE/SD r= M

Patients with available B12, folate at baseline 92 406 

-

0.168 NS 3.9 

-

0.126 NS 

Patients with available B12 either at baseline or during follow-up 

114 396 

-

0.102 NS 

Patients with available folate either at baseline or during follow-up 

111 5 

-

0.066 NS 
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LDCT 

(Sr) (B 12) (ng/L) p (Sr) (folate) (mg/L) p (Sr/CSF) (B vit) (unit) (S

Description of (Sub-) Groups 

N 

Mean SE/SD r= Mean SE/SD r= Mean SE/SD r= M

Patients with available B12, folate at baseline 92 406 0.031 NS 3.9 0.085 NS Patients with available B12 either at baseline or during follow-up 

114 396 0.081 NS 

Patients with available folate either at baseline or during follow-up 

111 5 0.042 NS 

WLTTOT 

(Sr) (B 12) (ng/L) p (Sr) (folate) (mg/L) p (Sr/CSF) (B vit) (unit) (S

Description of (Sub-) Groups 

N 

Mean SE/SD r= Mean SE/SD r= Mean SE/SD r= M

Patients with available B12, folate at baseline 92 406 0.075 NS 3.9 0.037 NS Patients with available B12 either at baseline or during follow-up 

114 396 

-

0.008 NS 

Patients with available folate either at baseline or during follow-up 

111 5 

-

0.080 NS 
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Delayed recall 

(Sr) (B 12) (ng/L) p (Sr) (folate) (mg/L) p (Sr/CSF) (B vit) (unit) (S

Description of (Sub-) Groups 

N 

Mean SE/SD r= Mean SE/SD r= Mean SE/SD r= M

Patients with available B12, folate at baseline 92 406 0.055 NS 3.9 0.214 <0.05 Patients with available B12 either at baseline or during follow-up 

114 396 0.011 NS 

Patients with available folate either at baseline or during follow-up 

111 5 

-

0.151 NS 

Unstandardized regression coefficients (95%CIs) of B12, folate adjusted for individual baseline age, sex, and educ

STROOP test LDCT WLTTOT 

Description of (Sub-) Groups 

N b coefficient 

 (Adj 1*) 

b coefficient 

 (Adj 1*) 

b coefficient 

 (Adj 1*) 

Patients with available B12 at baseline 92 4.24 -22.92, 31.39 -7.66 -17.19, 1.86 0.70 -8.93, 10.33 -0Patients with available folate at baseline 92 -2.31 -4.98, 0.37 0.54 -0.42, 1.51 0.34 -0.63, 1.3 0.3Patients with available B12 either at baseline or during follow-up 114 -0.69 -32.75, 31.37 -3.26 -11.47, 4.95 -1.17 -9.28, 6.93 -0Patients with available folate either at baseline or during follow-up 111 -0.27 -3.03, 2.5 -0.05 -0.74, 0.65 -0.47 -1.14, 0.21 -0* Adj 1, adjusted for age, sex, and educational level ** p<0.05; all other comparisons NS 
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Correlation

Author, Year: Tripathi, 2001 Ref ID: 733 Vitamins: B12 

Objective: Review of B12 status in dementia Study characteristics Population Controls* Inclusion criteria Exclusion 

criteria 

Defi

XS Age: 61.6+/-

6.6 

60.2+/-6.6 Cases: 

Comparative %Male:

AD: 

Study design 

Pro/Retrospective Race: 

Cases: Seen in cognitive disorders clinic, documented cobalamin level (Prospective n=54, Retrospective n=56)

PD: 

Country: India Other: Controls: Controls: Vasc

dem

Setting: Clinic OtheFunding: nd Comments: * Vascular or other dementias Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population of inSerum B12* pg/mL Diagnosis of AD N enrolled: 38 

N analyzed: 38 Drop-outs (%): 

Comments: * Micropore enzyme immunoassay (MPEIA). Normal: 187-1057 pg/mL; Indeterminate: 157-187 pg/mL; Low: <157 pg/mL. ** Vascular or other dementias Other predictors/outcomes reported: Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Mixture of prospective and retrospective Quality (A/B/C): C Applicability (1/2/3): Outcome(s): Results (Text) 
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Correlation of Predictors with Outcomes (cross-sectional studies) 

Serum B12 Low* p Serum B12 pg/mL p 

Description of (Sub-) Groups 

N 

n % Mean SD 

AD (probably/possible) 38 15 39.5% 263 168 Vascular and other dementias* 62 8 12.9% <0.05 289 139 <0.05 * <187 pg/mL, implied ** Including mixed, diffuse Lewy body disease, infections, nutritional, head injury, systemic, extra-pyramidal, etc. 
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Correlation

Author, Year: Wahlin, 1996 Ref ID: 3433 Vitamins: B12, folat

Objective: To examine the relationship between low B12 (<200 pmol/L) and folate (<11 nmol/L), separately and combined, and 

performance in very old age 

Study characteristics Population Controls Inclusion 

criteria 

Exclusion criteria 

XS Age: 85 Cases: Cases: Comparative %Male: 18% 

Study design 

Prospective Race: white 

Nondemented elderly 

Psychiatric dx; no B-12 or folate levels; ofolate, drugs interfere with folate uptake; neuroleptics & antidepressants without a pdx 

Country: Sweden Other: Controls: Controls: Setting: Lived in 

Kungsholmen district in Stockholm 

Funding: Predoctoral fellowship grants Comments: Predictor(s): (eg, B vit level) 

Outcome(s): Definition: Total 

Normal B-12, normal folate 

 Free-Recall 

performance 

2 memory lists of 12 concrete nouns; one list presented at a rate of 2 seconds/word, and the other presented at a rate of 5 seconds/word; subjects were told to remember as many words as possible for subsequent free-recall tests 

N enrolled: 

250 

Low B-12 (<200 pmol/L), normal folate 

 Recognition test After free-recall of each list, yes-no recognition tests were 

given, in which 12 target words were presented intermixed with an equal number of detractors; participants responded orally 

N analyzed: 

250 

Normal B-12, low folate (<11 nmol/L) 

Drop-outs (%): 

0 

Low B-12, low folate Comments: 
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Other predictors/outcomes reported: Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Quality (A/B/C): B Applicability (1/2/3): Outcome(s): Results (Text)  Free Recall: Normal B-12, normal folate group performed better than Low B-12, low folate group and Normal 

nmol/L) group by ANOVA (p<.01) 

 Recognition: Normal B-12, normal folate group performed better than Low B-12, low folate group and Normal 

nmol/L) group by ANOVA (p<.01). No significant interaction effects between vitamin group and study time in 

 Contrasting results from the analyses in which vitamin status was used as a categorical variable and those in wh

continuous variable suggest that vitamin B12 and folate may affect episodic memory functioning only among thvitamin levels are relatively low. 
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Correlation

Author, Year: Wang, 2001 Ref ID: 3445 Vitamins: B12, folat

Objective: To explore whether low serum levels of vitamin B12 and folate constitute risk factors for dementia, in particular for AStudy characteristics Population Controls Inclusion criteria Exclusion criteria 

Longitudinal Age: 

75-79 80-84 85-89 90-101

n=81 n=97 

n=119 

n=73 

Cases: Cases: 

Noncomparative %Male: 19% 

Study design 

Prospective Race: Probably 

100% 

white 

All non demented and those without a vitamin treatment and participated in the Kungsholmen project (a large longitudinal population based study) on aging and dementia that included all inhabitants born in 1912 or earlier and lived in one area of Stockholm on October 1987. 

Those who were demented and taking B 12 or folate supplementation and vascular dementia 

Country: Sweden Other:Education 

>7 yr 

36% Controls: Controls: 

Setting: Academic 

hospital 

Alcohol consumption 

78% yes 

Funding: Private foundations; partly gov 

None 

Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population of inVitamin B12 pmol/L N enrolled: 370 Folate nmol/L N analyzed: 

Drop-outs (%): 

Comments: 2 different cutoffs were used to define folate and B12 deficiency. For B12 the lower and higher cut-off points were 1

and for folate it was ≤10 and ≤12 nmol/L was chosen 
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Other predictors/outcomes reported: Follow-up duration (if applicable): 3 years Reasons for drop out (if applicable): Limitations: 2 different cut-offs Quality (A/B/C): B Applicability (1/2/3): Outcome(s): Results (Text) Prevalence of B12 and folate deficiency at baseline (cross-sectional studies) At baseline 

Sr B12 

≤150 

pmol/L 

n=58 

p Sr B12 ≤250 pmol/L n=175 p Sr Folate n=54 ≤10 nmol/L 

Description of (Sub-) Groups 

N 

Mean SE/SD Prevalence Mean SE/SD Prevalence Mean SE/SD Prevalence 

MMSE score ≤ 26 173 nd 17.3% NS nd 52.6% NS nd 22.1% <0MMSE score > 26 197 nd 14.2% nd 42.6% nd 8.2% Number of incident cases(n) and relative risks (RR) of Alzheimer’s disease and dementia in relation to baseline vitamin levels 

Alzheimer’s disease N D

Description of (Sub-) Groups 

N Crude RR 

(95% CI) 

RR (Adj 1*) 

(95% CI) 

Crude RR 

(95% CI) 

 1.7 (0.9-3.1) 1.6 (0.9-2.8) 1.4 (0.8-2B12 ≤150 vs >150 pmol/L 14 vs 46 15 vs 63 Folate ≤10 vs >10 nmol/L 12 vs 1.8 (1.0-3.4) 1.7 (0.9-3.2) 15 vs 1.7 (1.0-3
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47 62 

B12 ≤150 or folate ≤10 nmol/L vs normal levels of both B12 and folate 

26 vs 

34 2.3 (1.4-3.8) 2.1 (1.2-3.5) 30 vs 48 1.9 (1.2-3

Adj 1, adjusted for age sex and education... AD association with 2 levels of vitamin B12 or folate 

Alzheimer’s disease 

Description of (Sub-) Groups 

N 

RR (Adj 1*) RR (Adj 2*) 

(Reference gp) Normal levels of both vitamins 34/268 1 1 Low B12 and normal folate levels 13/47 0.7 (0.1-5.4) 0.6 (0.1-4.4) Low folate and normal B12 levels 11/43 2.1 (1.1-4.1) 1.7 (0.9-3.3) Low levels of both vitamins 1/11 2.3 (1.2-4.6) 1.2 (0.5-2.5) (Reference gp) Normal levels of both vitamins 34/268 1 1 Low levels of vit B12 or folate 25/101 2.1 (1.2-3.5) 1.4 (0.8-2.4) Adj 1, adjusted for age sex and education... Adj 2, adjusted for age, sex, education and cognitive functioning... Association of vitamin levels vs normal levels stratified by cognitive functioning 

Alzheimer’s disease 

Those with MMSE score ≤26 Description of (Sub-) Groups N OR (Adj 1*) OR (Adj 2*) 

(Reference gp) Normal levels of both vitamins 25/112 1 1 Low B12 or folate levels 18/60 1.5 (0.8-2.7) 

Alzheimer’s disease 

Those with MMSE score >26 
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(Reference gp) Normal levels of both vitamins 9/156 1 1 Low B12 or folate levels 7/41 3.1 (1.1-8.4) 
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Correlation

Author, Year: Whyte, 2002 Ref ID: 3509 Vitamins: B12 

Objective: To examine the relationship between B12 serum levels and cognitive and neuropsychiatric symptoms in dementia Study characteristics Population Controls Inclusion criteria Exclusion 

criteria 

XS Age: 78.9±7.73 75.1±7.84 Cases: Cases: Comparative %Male: 30 32 

Study design 

Prospective Race: White 

97% 

White 

90% 

Community dwelling elderly patients who consecutively evaluated in a University Clinic between Sep 1991 and June 1999 and were found to have probable or possible AD; Low B12 ≤200pg/mL 

ND 

Country: US Education, 

yr 

12.9±3.88 11.9±3.03 Controls: Controls: 

Setting: University 

Clinic (outpatients) 

Funding: ND 

Community dwelling elderly patients who consecutively evaluated in a University Clinic between Sep 1991 and June 1999 and were found to have probable or possible AD; Normal B12 ≥

201pg/mL 

ND

Comments: Mean age was significantly different between the 2 groups (p=0,01) Predictor(s): (eg, B vit level) 

Outcome(s): Definition: Total 

B12 Low ≤ 200 

pg/mL 

Folstein MMSE, Mattis DRS, CDR scale, CERAD BRSD, Hachinski scale, Modified Rey Figure Copy, Immediate, and 

Delayed Recall, Verbal Fluency, Benton Visual Form Discrimination, world List Learning with Immediate and Delayed Recall 

N enrolled: 

643 

N analyzed:

643 

Dropouts (%): N/A 

Comments: ND on the methods B12 was measured; descriptions of tests are given by REF (18-24, 27-30) Other predictors/outcomes reported: Regression techniques for comparing scores between different groups were adjusted for the 

education 
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Follow-up duration (if applicable): N/A Reasons for drop out (if applicable): N/A Limitations: Majority of subjects are white women; power calculations not reported Quality (A/B/C): B Applicability (1/2/3): Outcome(s): Results 

B12 low 2 ≤ 200pg/mL SD B12 normal ≥ 201pg/mL SD 

Folstein MMSE 14.73 7.33 16.94 5.66 Mattis DRS 105.4 25.02 110.82 18.03 Blessed 2.63 5.07 2.27 3.88 CDR scale (0) 1 2.7 2 0.3 CDR scale (1) 18 48.7 385 63.7 CDR scale (2) 13 35.1 183 30.3 CDR scale (3) 5 13.5 34 5.6 CERAD BRSD (total) 93.1 68.4 87.74 61.32 Hachinski scale 2.97 1.72 Modified Rey Figure Copy 17.46 5.61 16.03 6.64 Modified Rey Immediate Recall 1.77 2.93 1.48 4.09 Modified Rey Delayed Recall (0) 11 44 212 42 Modified Rey Delayed Recall (<10) 15 56 225 50.5 Modified Rey Delayed Recall (>10) 0 0 38 7.5 Verbal Fluency 8.32 3.06 9.36 4.14 Benton Visual Form Discrimination 23.59 4.74 World List Learning with Immediate 3.04 1.51 2.88 2.01 World List Learning with Delayed Recall 1.36 1.68 0.99 1.71 
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Correlation

Author, Year: Woitalla, 2004 Ref ID: 3543 Vitamins: B6, B12 a

Objective: To compare levels of B6, B12, folate and total plasma homocysteine (t-hcys) in plasma of levodopa treated PD pts, su

C677T genotypes and controls 

Study characteristics Population Controls Inclusion criteria Exclusion criteria 

XS Age: 65 58 (n=44) Cases: Cases: Comparative %Male: 57% 51% 

(n=41) 

Study design 

Prospective Race: 

PD pts only, on levodopa and dopa decarboxylas inhibitors 

Metabolic disturbances like diabeteabnormal vitamin values or vitamin supplementation 

Country: Germany Other: Controls: Controls: Setting: Funding: Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Population of PD t-hcys N enrolled: 127 83 PD with CT allele subgroup B6 N analyzed: PD with TT allele subgruop B12 Drop-outs (%): PD with CC allele subgroup Folate Comments: Other predictors/outcomes reported: Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Text description of results contradict results in tables 1 and 2 (?)Quality (A/B/C): C Applicability (1/2/3): Outcome(s): Results (Text)  There were significant different t-hcys concentrations in PD pts and controls.  Concentrations of B6 or B12 did nto differ, but folic acid was significantly higher in PD pts with CT allelele.  There was no impact of the covariates (sex and age) on the results. 
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Correlation of Predictors with Outcomes (cross-sectional studies) 

Plasma t-hcys μmol/L p Sr B-6 mg/L p Sr B-12 mg/L 

Description of (Sub-) Groups 

N 

Mean SE/SD Mean SE/SD r= Mean SE/SD r= M

PD 83 17.9 9.84 18.7 6.69 371.45 218.43 CT allele 38 14 5.7 CT vs. control 0.0004 20.65 7.49 322.55 119.89 TT allele 12 22 8.58 TT vs. control 0.03 18.25 5.72 369.58 172.5 CC allele 33 20.9 12.3 CC vs. CT 0.0029 16.62 5.43 428.42 298.7 Control 44 13.01 5.49 19.23 8.71 417.86 232.95 
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Correlation / FFQ

Author, Year: Chen, 2004 Ref ID: 575 Vitamins: Folate, B6

Objective: To investigate whether intake of folate or of related B vitamins that are involved in folate and homocysteine metabolis

Parkinson’s disease (PD) risk 

Study characteristics Health 

Professionals 

Follow-up Study

Nurses’ Health Study 

Inclusion criteria Exclusion criteria Definitions 

Longitudinal Age: 40-75 30-55 Cases: Comparative %Male: 100 0 

Study design AD: N

Prospective Race: ND ND 

All newly developed PD cases in both Health Professional Follow-up cohort (men) and Nurse’s Health cohort (women) from 1986 and from 1980, respectively, to the end of the follow-up (January 31, 2000, in men and May 31, 1998, in women) 

PD: A

rwpnPnb

Country: US Other: Controls: 

Participants who reported PD (n=178), stroke (n=505), or cancer (other than nonmelanoma skin cancer, n=5572), at baseline were excluded from the analyses. In addition, participants with extreme daily energy intakes (<800 or >4200 kcal for men; <500 or >3500 for women) or incomplete FFQ at baseline (>70 blanks for men or >10 for women) were excluded from the analyses. 

VascDz: N

Setting: Populationbased (2 

large cohorts in US) 

Other: 

Funding: NIH 

All subjects without a diagnosis of PD in the cohorts. 

Comments: 2 nested case-control studies were analyzed separately and then pooled analyses were also performed. 
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 Outcome(s): Definition: Total Po

N enrolled: 136,057 

Folate intake quintiles 

N analyzed: 

136,057 

Vitamin B6 intake quintiles 

Drop-outs (%): 

N/A 

Vitamin B12 intake quintiles 

FFQ during the previous 12 months, with 9 possible response categories ranging from “never” to “6 or more times per day.” Information on the dose and duration of supplemental use of specific vitamins and multivitamins was also collected. The nutrient composition of foods was estimated from the Harvard University Food Composition Database that was derived from the US Department of Agriculture and supplemented with information from manufacturers and data from peer-reviewed literature. Validations studies have been done. 

RR of PD Cox proportional 

hazard models controlling for age, smoking status, caffeine intake, alcohol consumption, and lactose intake. 

Folate supplement use 

Nonusers, < 400 μg/day, ≥ 400 μg/day 

Vitamin B6 supplement use 

Nonusers, < 1.7 mg/day, ≥ 1.7 mg/day 

Vitamin B12 supplement use 

Nonusers, < 2.4 μg/day, ≥ 2.4 μg/day 

Pooled RR of PD 

Log relative risks (RRs) from the 2 cohorts were pooled by the inverse of their variance. 

Note: Original cohort was

participants were not includ

various reasons stated in 

Comments: The p value for linear trend was calculated by using the median of each quintile category as a continuous variable in thOther predictors/outcomes reported: Follow-up duration (if applicable): An average of 12.7 years in men and 17.3 years in women Reasons for drop out (if applicable): Limitations: Quality (A/B/C): A Applicability (1/2/3): 
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Outcome(s): Results (Text) RR of PD Controlling for age, smoking, alcohol consumption, caffeine intake and lactose intake, there was no significant 

between the baseline intake of folate, vitamin B6, or vitamin B12 in the Health Professionals Follow-up studNurse’s Health Study (1980-1998) and multivariate relative risk of Parkinson’s disease: all RRs in each quindifferent from 1.0 and the p values for the trend of RRs across quintiles for all vitamin examined were not si

Individuals at either the low end (≤200 μg/day) or the high end (>1000 μg/day) of folate intake had a Parkinson

the risk of those with normal folate intake, controlling for age, smoking, alcohol consumption, caffeine intak

Supplemental intake of folate, vitamin B6, or vitamin B12 was also not related to the risk of Parkinson’s diseas

nonusers, individuals whose supplemental folate intake was more than 400 μg/day had a pooled RR of 1.0 (9

Note: Detail RR data by quintiles or by supplemental intake categories were showed in tables. 
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Correlation / FFQ

Author, Year: Deijen, 2003 Ref ID: 765 Vitamins: B1, B2, B

Objective: To elucidate the relation between nutritional intake and daily functioning in psycho-geriatric elderly people Study characteristics 

Population 

Inclusion criteria 

Exclusion criteria 

XS & Longitudinal 

Age: 83.0±7.0 

SD 

Non-Comparative %Male: 13% 

(12/90) 

Study design 

Prospective Race: ND 

Country: Netherlands BMI: 24.9±4.0 

110 psychogeriatric residents of a nursing home 

Psychiatric history, need of terminal care, suffrom cancer, rheumatoid arthritis, insulin depediabetes, serious overweight (BMI > 30 kg/mhaving a fiber-poor diet or a diet that can not bcombined with food supplementation; younge65 years. The data from 20 subjects were excluded from evaluatito incomplete data or failure to complete the total invesperiod. 

Setting: Nursing home Funding: Numico Research B.V. Comments: During the study 60% of the dropouts became ill against 34% of the subjects who completed the study. In addition, wi

dropouts, the percentage of males was higher than that of the study group (30% and 13% respectively) 

Predictor(s): (eg, B vit level) Outcome(s): Definition: 

N enrolled: 

Thiamin intake (?) 

N analyzed: 

Riboflavin intake (?) 

Drop-outs (%): 

Vitamin B6 intake (mg) 

A combination of a 3-day record and weighing-back methods at baseline, week 8, 16 and 24 (Nurses recorded). 

Zorg Index Geriatrie (ZIG)- scales 

The ZIG-scale consists of the ZIG-A scale 

(cognitive functioning), ZIG-B scale (physical functioning) and the ZIG-C scale (social functioning). The ranges of the ZIG-scales are from 

6 to 24. The nursing-home caregiver(s) assessed subject’s ZIG-scales. 

Comments: For the purpose of this review, only ZIG-A scale (cognitive functioning) is the outcome of interest. 

In correlation analyses, nutrition parameters were averaged for each subject across the 12 assessments: 3 across 1 wee

determine possible relationships between the various nutrient s and ZIG-scores, partial correlations, controlling fobivariate correlations were computed by two-tailed tests. 

In longitudinal analyses, repeated measures analyses on the 4 data point (week 0, 8, 16 and 24) of the ZIG-scores and 

used. 
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Other predictors/outcomes reported: 

Age; weight; BMI; energy, vitamin A, niacin, vitamin C intakes 

Follow-up duration (if applicable): 

6 months 

Reasons for drop out (if applicable): 

Incomplete data or failure to complete the total investigation period. During the study 60% of the d

against 34% of the subjects who completed the study. 

Limitations: Subjects were recruited from a nursing home (limited applicability). 

Dropouts had worse health status than the completers. If the outcome assessors (nursing-home caregivers) and the exposure assessors (nurses) were the sa

misclassification bias would occur. 

The results clearly showed that subjects with high vitamin and energy intake were younger than tho

However, the correlation analyses only controlled for BMI not age. 

Quality (A/B/C): C Applicability (1/2/3): Outcome(s): Results (Text) ZIG-A (cognitive) scale 

Longitudinal analysis (repeated measurements analyses) were carried out with ZIG-scores as repeated measure

comparisons were separately made between low/high intake groups of vitamin B-6 as between subjects factogroups were formed based on high and low intakes of nutrients compared to the median intakes at baseline. 

between intake groups and week, indicating that the high and low intake groups had the same pattern of ZIGmonth experimental period. 

Disregarding the factor intake group, a significant increase in all ZIG scales was found across weeks (p<0.0005

deterioration in cognitive, physical and social functioning takes place in the course of the 6-month study per

No significant increase of dietary vitamin B6 was seen across weeks. 

Correlation of Predictors with Outcomes (cross-sectional studies) 

Mean 

intake of

Thiamin 

(unclear

unit)

Mean 

intake of 

Riboflavin

(unclear

unit)

Mean 

intake of 

Pyridoxine 

(unclear

unit) Outcome N 

r=* p r=* p r=* p

ZIG-A (cognitive) scale, higher scores indicate worse cognitive function 

90 0.25 0.02 0.23 0.03 ND NS 

*Partial correlations, controlling for BMI 
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Correlation / FFQ

Author, Year: Lee, 2000 Ref ID: 1813 Vitamins: B1; B2 

Objective: To analyze the association between dietary intake and cognitive function of the Korean elderly Study characteristics Population

Men Women 

Inclusion criteria Exclusion criteria Definitio

XS Age: 72.3±6.5 

SD 

69.6±6.0 

Non-Comparative %Male: 47% (210/449) 

Study design AD: 

Prospective Race: Koran PD: 

Country: Korea BMI: 23.3±3.4 24.5±4.1* VascDz: Setting: Community 0.91±0.05 0.88±0.05* 

(primarily 2 elderly welfare centers) 

WHR: 

*p<0.01 b/w groups 

Funding: University 

A random sample of elderly people who usually spend the daytime at the welfare center 

Major cognitive function impairment. 

Cognitive accordinnormal (24), and 

Comments: Due to many significant differences in the anthropmetric measurements (e.g. BMI, height, weight, waist/hip ratio (WH

women should be discussed separately because all analyses were univariate. MMSE-K (Mini-Mental State Examination for Koreans) modified from Folstein et al’s MMSE. 

Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Pop

i

N enrolled: 449 

Thiamin intake (mg) 

Single 24-hr recall 

N analyzed: 449 

Riboflavin intake (mg) 

Single 24-hr recall 

MMSE-K Status Points ranged from 0 to 30. Normal 

(≥24), inadequate (19-24), and poor (≤19) Drop-outs 

(%): 

N/A 

Comments: 24 h diet recalls were done by a trained interviewer and with the use of food models. Nutrient intakes were calculated 

Aided Nutritional (CAN) analysis software program developed by The Korean Nutrition Society. Incomplete and inc

excluded. 
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Other predictors/outcomes reported: 

Age; education level; BMI; WHR; Food intakes; intakes of the major macro- and micro- nutrients 

Follow-up duration Reasons for drop out Limitations: Single 24-hr dietary recall cannot account for the day-to-day variations of nutrient/food intakes. 

Subjects may not represent the general elderly population in Korea. Age and education levels were found to be strongly related to cognitive function in both men and women

association between food/nutrient intakes and MMSE-K status were not adjusted for these confoundeducation levels or younger age could give a more accurate 24-hr dietary recall, resulting in biases aw

Quality (A/B/C): C Applicability (1/2/3): Correlation of Predictors with Outcomes (cross-sectional studies) 

Dietary Intake of Thiamin (mg) p Dietary Intake of Riboflavin (mg) p 

Description of (Sub-) Groups 

N 

Mean SD r=** Mean SD r=** 

Men –  Normal (≥24) 136 0.95 0.35 0.87 0.46  Inadequate (19-24) 48 0.91 0.34 0.77 0.37  Poor (≤19) 26 0.82 0.27 

0.083 NS 

0.74 0.32 

0.082 NS 

Women –  Normal (≥24) 86 0.91 0.39 0.68 0.33  Inadequate (19-24) 79 0.90 0.63 0.72 0.50  Poor (≤19) 74 0.71* 0.35 

0.125 NS 

0.50* 0.32 

0.144 <0.05 

*values are significantly lower, p<0.05 by Duncan’s multiple range test **age controlled 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Human Studies 

C-252 

Correlation / FFQ

Author, Year: Mizrahi, 2003 Ref ID: 2188 Vitamins: B6; folate 

Objective: To examine the relationships of total plasma homocysteine levels (tHcy), dietary vitamin B6 and folate, ApoE genotyp

blood lipids and serum albumin in Alzheimer’s disease (AD) patients and healthy controls 

Study characteristics Population Controls Inclusion criteria Exclusion criteria 

Case-Control study 

Age: 74.1±7.9 

SD 

74.6±6.9 Cases: For all participants:

Comparative %Male: 45.3 45.3 

Study design 

Retrospective Race: ND ND 

Cases were recruited from a Research Registry at an Alzheimer Center. Cases were matched by gender, year of birth, and smoking status to a pool of 382 healthy controls using propensity scores. 

Country: US %Current 

smokers: 

4.7 6.3 Controls: 

Setting: Registry Education, 

years 

12.5±2.9 15.2±2.8* 

MMSE score (maximum 30) 

17.7±6.8 28.8±1.1* 

%ApoE genotype, with 1 or 2 epsilon 4 

61.7 14.3* 

*p<=0.001 between groups

Funding: Non-profit organizations; NIH 

Controls age 60 years or older were recruited from friends or neighbors of cases or members of the organizations to which cases belonged. 

Presence of pernicious anemia, renal impairment, hypothyroidism, carcinoma of the breastovary and pancreas, severe psoriasis, and drugs (folate antagonists: methotrexate, phenytoin and carbamazepine and B6 antagonists: theophylline, azarabineoestrogen-containing oral medications) known to increase tHcy levels 

Comments: Matched pairs analysis was only performed for the relationship between tHcy levels and the odds ratio for AD, which w

to our report. The relationships between B6 or folate intakes and AD were done using unmatched analysis (two-sample adjust for the necessary covariates. 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Human Studies 

C-253 

Predictor(s): (eg, B vit level) Outcome(s): Definition: Total 

N enrolled: 446 

Vit. B6 intake (mg/1000Kcal) 

N analyzed: 

128 

Folate intake (mg/1000Kcal) 

FFQ adapted from the Block Health Habits and History Questionnaire (HHHQ). Medium-sized portion is assumed for every food. Nutrient analyses of dietary consumption used folate values in foods before the US FDA made folate enrichment mandatory in January 1998. 

Drop-outs (%): 

N/A 

tHcy (μmol/L) Samples were run on the Abbot Imx 

Platform, which is a fluorescence polarization immunoassay 

AD patients vs. healthy controls 

Two-sample t-tests for 

detecting differences between the 2 groups at 3 age periods: 20-39 years, 40-59 years, and 60+. 

Spearman correlation was 

used for correlations between tHcy levels and dietary Vit B6 and folate being consumed in the 3 age periods between AD patients or controls separately. 

Comments: Missing data on dietary intake for some of the participates resulted in slightly different sample sizes for the various Other predictors/outcomes reported: 

ApoE genotype; triglycerides; cholesterol; LDL 

Follow-up duration Reasons for drop out Limitations: FFQ is subject to recall biases and not a good method to assess absolute amount of dietary intakes. Con

accurate recalls than the cases, because proxy or surrogate respondents were used to estimate cases’ 

periods (20-39 years, 40-59 years, and 60+ years)! 

Two-sample t-tests were used to compare the mean levels of dietary folate and vitamin B6 for AD patie

periods: 20-39 years, 40-59 years, and 60+. This analysis dosen’t adjust for the necessary covariates

Quality (A/B/C): C Applicability (1/2/3): Outcome(s): Results (Text) AD patients vs. healthy controls 

No statistically significant correlations were found between tHcy levels and dietary vitamin B6 and folat

age periods between AD patients or controls (Spearman correlation; p>0.05) 

AD patients had lower mean dietary vitamin B6 intake than controls in the 60+ years age period (p=0.05

their 20-39 years (p=0.58) and 40-59 years age periods (p=0.61). 

AD patients had lower mean dietary folate intake than controls in the 60+ years age period (p=0.01), but 

39 years (p=0.6) and 40-59 years age periods (p=0.14). 

Note: Data for the dietary B6 and folate intakes were reported in figures. 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Human Studies 

C-254 

Correlation / FFQ

Author, Year: Renvall, 1989 Ref ID: 2686 Vitamins: B1, B2, F

Objective: To test the hypotheses that dietary intake and biochemical values of vitamin B12, folate, thiamine and energy would b

of the Alzheimer’s type (SDAT) patients than in elderly patients with normal cognition. 

Study characteristics Population Controls 

♂ ♀ ♂ ♀

Inclusion criteria 

Exclusion criteria 

D

XS Age: 75.4 77.9 71.1 71.4 Cases: For all 

participants: 

Comparative %Male: 32%(7/22) 38%(13/41) 

Study design A

Prospective Race: ND ND 

Program participants who had a diagnosis of senile dementia of the Alzheimer’s type (SDAT) 

P

Country: US Controls: VSetting: Outpatient geriatric 

assessment program 

%MultiVit users: 

50% 48% 53% 42% 

Funding: NIH 

Elderly people (program participants) who were at least 60 years of age and free from acute illness or recent hospitalization. 

Subjects who did not complete the 3-day dietary record (n=6). Not all biochemical values were obtained from the subjects completing the dietary record. Information for each parameter is presented only for those subjects from whom both dietary and biochemical data were available. 

S

Comments: There was also a retrospective study (serum vitamin status only). Only the prospective study is reviewed here. 

SDAT patients (or population of interest) were significantly older than normal subjects. 

Biochemical values, age, MMSE scores and living situation did not differ between the excluded and included subjects

excluded subjects was significantly (p<0.006) lower than that of the participants. 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Human Studies 

C-255 

Predictor(s): (eg, B vit level) Outcome(s): Definition: Total Po

N enrolled: 

69 

Thiamin intake (mg/day) (n=48) 

N analyzed:

<63 

Riboflavin intake (mg/day) (n=51) 

Dropouts (%): >8.7% 

Folate intake (μg/day) (n=37) Vitamin B12 intake (μg/day) 

(n=43) 

Subjects or their caregivers were given oral and written instructions in keeping written 3-day food consumption records. The records were analyzed by computer program (Ohio State University) and missing values were added from atandard handbooks of food composition. Multivitamin supplements were taken sporadically by many of the subjects; therefore, values from supplements were not added to those of the diets. 

Blood thiamin level 

Activity of RBC transketolase assay 

Riboflavin ratio The riboflavin content of casual urine 

samples was measured fluorometrically and corrected by creatinine concentration. 

SDAT vs. normal subjects 

ANOVAR followed by Bonferroni tests, when appropriate, was used to measure differences among means for dietary and biochemical parameters. For this analysis, subjects were grouped by 1) cognition; 2) sex and cognition; or 3) supplement use and cognition 

Comments: Dropout rates were larger than 8.7% because only subjects who had both dietary and biochemical data were analyzeOther predictors/outcomes reported: 

Protein, energy, and iron intakes; RBC folate and serum vitamin B12; serum protein; serum albumin; h

Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Only subjects who had both dietary and biochemical data were analyzed. Dropout rate for some measure

3-day dietary records by subjects or their caregivers. No description which days in a week. The self-reported dietary intake and the biochemical values (blood markers) were weekly correlated. Cor

not shown) between the measures of nutritional status were higher in normal subjects than in SDAT SDAT subjects had poorer dietary recalls. This confounding factor was not adjusted for in the analys

Quality (A/B/C): C Applicability (1/2/3): 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Human Studies 

C-256 

Correlation of Predictors with Outcomes (cross-sectional studies) 

 SDAT subjects Normal Subjects 

Dietary values Mean±SD [95%CI] Mean±SD [95%CI]

Thiamin, mg/day 

 (n=48, p<0.54) 

1.4±0.8 (n=15) 

[0.9-1.8] 

1.2±0.4 (n=33) 

[1.1-1.4] 

Riboflavin, mg/day  (n=51, p<0.66) 

1.6±0.6 (n=14) 

[1.3-1.9] 

1.5±0.6 (n=37) 

[1.3-1.7] 

Folate, μg/day  (n=37, p<0.54) 

169±74 (n=27?) 

[140-198] 

186±71 (n=10) 

[135-236] 

Vitamin B12, μg/day 

 (n=43, p<0.31) 

2.3±1.8 (n=21?) 

[1.5-3.1 

2.9±2.3(n=22) 

[2.0-4.0] 

Biochemical values Mean±SD [95%CI] Mean±SD [95%CI]

Thiamin 

ETKAS, IU/ml/hr  (n=48, p<0.49) 

4.3±1.6 (n=15) 

[3.4-5.2] 

3.9±1.6 (n=33) 

[3.3-4.5] 

ETKAPH, IU/min/g hemoglobin  (n=51, p<0.055) 

1.5±0.5 (n=14) 

[1.3-1.8] 

1.89±0.4 (n=28) 

[1.7-2.0] 

Riboflavin ratio  (n=51, p<0.44) 

1.9±1.9 (n=14) 

[0.8-3.0] 

3.1±5.9 (n=37) 

[1.1-5.1] 

? Questionable values perhaps due to reporting errors 

Supplement Users Supplement Nonusers

SDAT Normal SDAT Normal 

Biochemical values Mean±SD Mean±SD Mean±SD Mean±SD

Thiamin 

ETKAS, IU/ml/hr  (n=48, p<0.48) 

4.6±2.0 

(n=7) 

3.8±1.7 

(n=18) 

3.9±1.2 

(n=8) 

4.0±1.5 

(n=15) 

ETKAPH, IU/min/g hemoglobin  (n=51, p<0.03) 

1.7±0.3 

(n=6) 

1.9±0.4* 

(n=15) 

1.4±0.6* 

(n=8) 

1.7±0.3 

(n=13) 

Riboflavin ratio  (n=51, p<0.01) 

2.7±2.1 

(n=8) 

4.7±7.6 

(n=21) 

0.8±0.6 

(n=6) 

1.0±0.6 

(n=16) 

* Significantly different means by Bonferroni correction: p<0.01 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Human Studies 

C-257 

Correlation / FFQ

Author, Year: Requejo, 2003 Ref ID: 2687 Vitamins: B1, B2, B

Objective: To study the importance of nutrition in the maintenance of cognitive function in a group of elderly people. Study characteristics 

Population 

Inclusion criteria Exclusion criteria 

XS Age: ≥

65 

Non-Comparative %Male: ND 

Study design 

Prospective Race: ND 

Country: Spain Other: Setting: Community Funding: ND 

Noninstitutionalized elderly people (≥ 65 y) who spent part of their time at day centers 

Any disease that might affect the food intak(neoplasms, liver or kidney disease, diabetetook medications that might influence the aptrying to gain or lose weight; manifest cogndecline (MMSE<24)

Comments: Predictor(s): (eg, B vit level) Outcome(s): Definition: To

N enrolled: 16

Thiamin intake (mg/day) 

N analyzed: 16

Riboflavin intake (mg/day) 

Drop-outs (%): 

N/

Pyridoxine intake (mg/day) Folate intake (μg/day) Vitamin B12 (μg/day) 

Precise individual weighing of food was performed for 5 days in order to monitor the food consumed at the midday meal, the only meal the subjects took at the centers. A 7-day food record was also kept, in which subjects noted all the foods they consumed. The energy and nutrient contents of the foods and drinks consumed were determined using the Institution of Nutrition’s Food Composition Tables (Instituto de Nutricion, 1994) 

Cognitive capacity 

Folstein’s MMSE was used. Points are awarded between 0 and 35, with 28 or more considered as normal. 

Comments: Since the test results get worse with advancing age (r=-0.2730, p<0.001), subjects were also grouped with res

(either above or below the 75th percentile (74.8 y]). The chi-square test was used to confirm the homogeneity 

between these groups. 

Other predictors/outcomes reported: Age; food consumption; other major macro- and micro- nutrients Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Subjects may not represent general elderly people in Spain Quality (A/B/C): B Applicability (1/2/3): 
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Correlation of Predictors with Outcomes (cross-sectional studies) 

Dietary Intake of Thiamin (mg/day) p Dietary Intake of Riboflavin (mg/day) 

Description of (Sub-) Groups 

N=168 

Mean SD Mean SD 

MMSE ≥ 28  Age < 75th percentile ND 1.12 a 0.34 1.43 a 0.40  Age ≥ 75th percentile ND 1.12 a 0.44 1.52 b 0.43 <0.0MMSE < 28  Age < 75th percentile ND 1.05 b 0.29 1.39 a 0.35  Age ≥ 75th percentile ND 0.96 b 0.23 

<0.1* 

1.46 b 0.38 <0.0

Difference in the subscripts indicates statistical significant differences between the groups. *Differences obtained with respect to MMSE score ** Differences obtained with respect to age 

Dietary Intake of Pyridoxine (mg/day) p Dietary Intake of Folates (μg /day) p 

Description of (Sub-) Groups 

N=168 

Mean SD Mean SD 

MMSE ≥ 28  Age < 75th percentile ND 1.40 0.39 202.0 a 73.7  Age ≥ 75th percentile ND 1.36 0.48 NS 222.9 a 113.8 MMSE < 28  Age < 75th percentile ND 1.39 0.32 182.9 b 60.5  Age ≥ 75th percentile ND 1.40 0.31 NS 180.5 b 64.3 

<0.05* 

Difference in the subscripts indicates statistical significant differences between the groups. *Differences obtained with respect to MMSE score 
Appendix C. Evidence Tables 

B Vitamin Evidence Table – Human Studies 

C-259 

Dietary Intake of Vitamin B12 (μg /day) p 

Description of (Sub-) Groups 

N=168 

Mean SD 

MMSE ≥ 28  Age < 75th percentile ND 7.3 7.9  Age ≥ 75th percentile ND 7.3 5.4 NS MMSE < 28  Age < 75th percentile ND 5.9 5.6  Age ≥ 75th percentile ND 7.4 8.0 NS 
Appendix C. Evidence Tables 

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Berry Evidence Tables – Animal / In Vitro Studies 
Appendix C. Evidence Tables 

Berry Evidence Tables – Animal / In Vitro Studies 

C-261 

Author, Year Saija, 1990

Central hypothesis/Stated Purposes of Study 

Myrtillinum (a purified Bilberry extract containing 15 anthocyanins) has capacity to affect T3 transport int

Hypothesis diagram Myrtillinum administration Æ changes in T3 transport into brain Experimental diets or reagents 

Myrtillinum (a purified Bilberry extract containing 15 anthocyanins) was injected intraperitoneally at the d

3 consecutive days. 

Control diets or reagents Vehicle (26% ethanol/water, v/v; volume of injection: 0.2 ml/100 g body weight) injections Study characteristics Country: Italy 

Funding source: ND 

Gap in Knowledge Known: Flavonoids have been demonstrated to be potent non-toxic iodothyonine deiodinase inhibitors in 

and in intact rat hepatocytes; they are specific high-affinity competitors for L-thyroxine (T4) binding to prealbumin, and very poor inhibitors of 3,3’,5-triiodothyronine (T3) binding to the nuclear T3 receptors

Unknown: The effects of myrtillinum (a purified Bliberry extract) on T3 transport into brain 

Experimental model Brain of adult Sprague-Dawley rats (330-350 g body weight) Study design 24-hr after the last injection, both vehicle- and myrtillinum-injected rats were decapitated 15 sec after ane

removed; tissue specimens were dissected from the ipsolateral hemisphere. 

Final sample size No Data Duration 3 days Measurements / Endpoints / Outcomes of interest 

Percent brain uptake index of [125I]L-T3, analyzed by different brain fractions 

Other outcomes reported Results Administration of myrtillinum induced a significant increase in T3 transport into frontal cortex, temporopa

cortexs, hippocampus, thalamus, hypothalamua and brain-stem (p<0.05). No significant change in T3 

inferior colliculus, and cerebellum. 

Authors’ Conclusions Administration of myrtillinum induced a significant and widespread increase in T3 transport into brain. Quality B Limitations / Comments There was no expected direction of effects of myrtillinum on T3 transport into brain to begin with. The pri

study (only 2 pages) is to find out what will happen and generate some possible hypotheses. Not sure 

findings from this study to the neurodegenerative diseases. 

No data on the numbers of animals 
Appendix C. Evidence Tables 

Berry Evidence Tables – Animal / In Vitro Studies 

C-262 

Author, Year Wang, 1996

Central hypothesis/Stated Purposes of Study 

To show the differential inhibition of eukaryote protein kinases by condensed tannins prepared from a variety 

including gooseberry (Ribes grossularia fruit), red currant (Ribes rubrum fruit), blueberry (Vaccinium corym

Hypothesis diagram Condensed tannins isolated from fresh fruits Æ inhibit PKC activities Experimental diets or reagents 

Condensed tannins (polymers consisting of flavan monomers, such as procyanidin and prodelphinidin units) 

(inhibitors), including gooseberry (exp#6), red currant (exp#17), and blueberry (exp#18). The composition 

stereochemistry proportions of these tannins are as below: 

Tannin preparation cis/trans Procyanidin/prodelphinidin MN

Gooseberry tannin 63/37 77/23 2700 Red currant tannin 24/76 78/22 2700 Blueberry tannin 100/0 96/4 3500 

Control diets or reagents 

N/A 

Study characteristics Country: New Zealand 

Funding source: Australian Research Council; University fund 

Gap in Knowledge Known: Previous study showed that a range of condensed tannin deriving from the cladodes of Phyllocadus 

of Pseudotsuga menziesii and the heartwood of Acacia melanoxylon are potent inhibitors of PKC and CD

relatively poorer inhibitors of cAK. 

Unknown: 

Experimental model Rat brain PKC (specific activity 0.6 μmol min-1 mg protein-1 with 3.5 μM EGFRP as substrate) was extensivel

standard assay conditions. Inhibitor IC50 values (concns for 50% inhibition of particular protein kinases in 

conditions) were determined from interpolation of plots of protein kinase activity versus inhibitor concn. Co

activity (no added inhibitor) was routinely determined 6 times and assays with inhibitor included were deteassay results were corrected by subtraction of blank values from assays conducted in the absence of add

Study design In vitro Final sample size N/A Duration N/A Measurements / Endpoints / Outcomes of interest 

Inhibitor IC50 values (μM) of rat brain protein kinase C (PKC) 

Other outcomes reported 

The composition and relative stereochemistry proportions of condensed tannin preparations Inhibitor IC50 values (μM) of chicken gizzard myosin light chain kinase (MLCK), wheat embryo CDPK, and ra

dependent protein kinase catalytic subunit (cAK) 

Results Tannin preparations from gooseberry (exp#6), red currant (exp#17), and blueberry (exp#18) have similar effe

rat brain PKC with IC50 values (0.7, 0.6, and 0.5 μM respectively) as each other and compared to other pl

Authors’ Conclusions Tannin preparations from gooseberry, red currant, and blueberry have similar effectiveness as inhibitors of raQuality A Limitations / Comments 

Not sure how relevant of the findings from this study to the neurodegenerative diseases. 
Appendix C. Evidence Tables 

Berry Evidence Tables – Animal / In Vitro Studies 

C-263 

Author, Year Joseph, 1998A [UI#9928436] and Bickford, 1999* 

Central hypothesis/Stated Purposes of Study 

Diets supplemented with vitamin E, strawberry extracts, spinach, or blueberry extracts may help anim

deleterious effects of 48 h of 100% oxygen exposure (normobaric hyperoxia) on several neuronal 

Hypothesis diagram Dietary antioxidants 

↓

Oxidative stress (OS) due to hyperoxia Æ X Æ reduce β -adrenergic receptor function in the cerebellu

Experimental diets or reagents 

Strawberry diet: control diet supplemented with strawberry extracts (9.4 g/kg dried aqueous extract) Blueberry diet: control diet supplemented with blueberry extracts (10 g/kg dried aqueous extract) 

Control diets or reagents AIN-93 Study characteristics Country: US 

Funding source: No data 

Gap in Knowledge Known: Research has indicated that animals maintained on diets containing fruits or vegetables that a

activity are more resistant to the deleterious effects of 48 h of 100% oxygen exposure on several nalso show declines in aging. 

Unknown: The effects of diets supplemented with vitamin E, strawberry extracts, spinach, or blueberr

neuronal parameters. [Note: for the purpose of this review, only diets supplemented with strawberextracts, and control diet are of interest] 

Experimental model 6- to 8- month-old F344 rats Study design Rats were fed the experiment or control diets for 8 weeks prior to 48 h of normobaric hyperoxia. Final sample size No data Duration 8 weeks Measurements / Endpoints / Outcomes of interest 

Dopamine release in striatal β -adrenergic receptor function in the cerebellum: isoproterenol modulation of GABA cerebellar Purkin

modulating). 

Other outcomes reported Results Data for the results of dopamine release in striatal is not shown. 

Rats fed diets supplemented with strawberry extracts were protected from the damaging effects of hy

-adrenergic receptor function of the cerebellar purkinje neurons (p<0.01). 

Authors’ Conclusions Diets supplemented with strawberry extracts and blueberry extracts were both effective in striatal oxo

dopamine release (data not shown) and β -adrenergic receptor function in the cerebellum. 

Quality C Limitations / Comments Joseph, 1998A is a review article with a paragraph reporting the preliminary data. Later, the data was 

of results in Bickford, 1999 

The amount of added food extracts at 1.36 mmol Trolox equivalents as determined by the ORAC assLimited data presented in the articles and need to cross reference for more complete reporting. Uncle

*This is a review article with some primary data in “3.4. Effects of hyperoxia on cerebellar physiology: nutritional interventions
Appendix C. Evidence Tables 

Berry Evidence Tables – Animal / In Vitro Studies 

C-264 

Author, Year Joseph, 1998B [UI#9742171] 

Central hypothesis/Stated Purposes of Study 

Role of long term feeding dietary phytochemicals and antioxidants to ameliorate or prevent age relat

functions and neurodegenerative diseases 

Hypothesis diagram Oxidative stress may be a factor in neuronal loss in aging and enhanced loss in age-related neurode

hence reduction in OS with exogenous antioxidant may help 

Experimental diets or reagents Strawberry 9.5 g/kg diet (also spinach and Vit E groups) Control diets or reagents Modified AIN-93 diet (described in table 1) Study characteristics Country: US 

Funding source: Government 

Gap in Knowledge Known: OS may play an etiological role in age related neurodegeneration and there is an age related 

endogenous antioxidants. Diets rich in fruits and vegetables have high antioxidants 

Unknown: Role of exogenous antioxidants to prevent loss of Ca homeostasis and loss of cognitive p

Experimental model Male Fischer rats, from age 6-15 months Study design Randomized controlled trial Final sample size 80 in total Duration 8 months Measurements / Endpoints / Outcomes of interest 

DA release from striatal slices, 45Ca recovery, cognitive testing, oxidative stress, GTPase activity 

Other outcomes reported Electrophysiology, weights and food intakes Results DA release: (assumed 8 animals per group) Significant oxotremorine-enhanced K+ evoked striatal d

ERDA) from animals maintained on strawberry diet compared to control diet (p<0.034). 45Ca recovery was significant greater in strawberry group exposed to H2O2 treatment but not in contr

H2O2 .(p<0.02) In the control diet 45Ca recovery was significantly decreased in the H2O2 exposed tcontrols.(p<0.001) 

Cognitive testing: Morris Water maze trial 1 showed a significant effect for strawberry group for laten

(p<0.01). No difference between strawberry and control on working memory trial 2 performance 

Oxidative stress: In the cerebellar tissue strawberry group showed increased native protection comp

(p<0.0001). 

GTPase activity: Age-induced decrements in carbachol stimulated GTPase activity were significantly 

control (p<0.0001). 

Authors’ Conclusions Phytochemicals present in antioxidant rich foods such as spinach may be beneficial in retarding func

CNS and cognitive behavioral deficits 

Quality A Limitations / Comments Pre trial data on the animals unknown 
Appendix C. Evidence Tables 

Berry Evidence Tables – Animal / In Vitro Studies 

C-265 

Author, Year Bickford, 1999* 

Central hypothesis/Stated Purposes of Study 

If oxidative stress is important for the development of age-related declines in CNS function, then treatmen

should prevent some of the neurodegenerative alterations observed during the aging process. 

Hypothesis diagram Diets supplemented with antioxidants Æ delay the onset of age-induced alterations in cerebellar physiolog

learning declines 

Experimental diets or reagents 

Not reported, but presumable same as previous study, as below: 

Strawberry diet: control diet supplemented with strawberry extracts (9.4 g/kg dried aqueous extract) 

Blueberry diet: control diet supplemented with blueberry extracts (10 g/kg dried aqueous extract) 

Control diets or reagents Not reported, but presumable same as previous study: AIN-93 Study characteristics Country: US 

Funding source: No data 

Gap in Knowledge Known: The noradrenergic input to cerebelaar Purkinje neurons inhibits spontaneous discharge and thus 

characterized as a ‘modulatoray” input. It has been shown that NE, applied iontophoretically or via acti

coeruleus, will potentiate GABA-induced inhibitions of cerebellar Purkinje neurons via the β-adrenergic 

NE is altered in aged rats such only 30% of cells in aged rats demonstrate this effect whereas 70%-80

young animals will show an increase in the response to GABA during application of isoproterenol (ISO

NE or blockade of β-adrenergic receptors impairs the ability of rats to improve performance on a runwamust learn to walk on varying patterns of pegs that protrude from the runway walls. 

Unknown: 

Experimental model 6-month-old F344 rats Study design Rat fed diets supplemented w/ (vitamin E), strawberry extracts, (spinach), or blueberry extracts, compared Final sample size No data Duration Long-term feeding: 9 months 

Short-term feeding: 2 months 

Measurements / Endpoints / Outcomes of interest 

Long-term feeding: 

β -adrenergic receptor function in the cerebellum: % neurons 

Short-term feeding: 

Rod walking motor learning task: Data collection begins when rat has performed 2 successful traverse

uncovered rods in less than 1 min. Daily performance calculated by determining the running time fo

Sessions are conducted for 5 days during this phase of training. (This measure was done for short-

ISO potentiation of GABA 

Other outcomes reported Results Long-term feeding: Strawberry supplemented diet improved β -adrenergic receptor function in the aged ra

control diet fed animals of the same age (p<0.01) 

Short-term feeding: Data not shown 

Authors’ Conclusions Long-term feeding: Long-term feeding of diets high in antioxidant potential is capable of delaying the onse

alterations in cerebellar physiology. 

Short-term feeding: Diets supplemented with strawberry extracts and bluebecrry extracts for 2 months rev

decline in both ISO potentiation of GABA and in motor learning. 

Quality C Limitations / Comments Limited data presented in the articles and need to cross reference for more complete reporting; Unclear m

*This is a review article with some primary data in “3.5. Effects of nutritional intervention on cerebellar physiology” 
Appendix C. Evidence Tables 

Berry Evidence Tables – Animal / In Vitro Studies 

C-266 

Author, year Joseph, 1999

Central hypothesis/Stated Purposes of Study 

To examine whether dietary supplementation with spinach, strawberry, or blueberry extracts would be effe

related deficits in neuronal and behavioral function in aged (19 months) rats. 

Hypothesis diagram Increase in dietary antioxidant levels Æ decrease OS Æ reversing age-related deficits Experimental diets or reagents 

1.48% strawberry extract;(0.91% spinach extract); 1.86% blueberry extract (w/v) added to a control diet o

Control diets or reagents Modified AIN-93 Study characteristics Country: US 

Funding source: supported by the US Department of Agriculture 

Gap in Knowledge Known: 

Unknown: 

Experimental model Fischer 344 rats had been shown to exhibit decrements by 15 months of age. Study design 19 month old Fischer 344 rats; 4 groups; each group was fed a different diet for 8 weeks; then was given Final sample size Control 10 rats; strawberry 10; blueberry 10 Duration 8 weeks Measurements / Endpoints / Outcomes of interest 

A battery of age-sensitive tests of psychomotor behavior was administered in a randomized order. Each t

separated by no less than a 1 hr break between tasks. The tests included rod walking; wire suspensio

screen and accelerating rotarod. 

 Cognitive testing used the working memory version of the Morris water maze. It was performed daily for 4 

morning and an afternoon session, two trials (trial 1 and trial 2) each session, with a 10 min intertrial in

Dopamine release GTPase activity: all striatal slices Ca 2+ recovery were examined in the striatal synaptosomes 

Analyses of oxidative stress 

Other outcomes reported Vitamin E analyses Results Psychomotor behavior: 

Significant effects of diet on rod walking (p<0.05) and the accelerating rotarod (<0.05). For the rod walk, latency to fall was significantly longer in the blueberry groups compared to control (p

(p<0.01) compared to control 

For the accelerating rotarod, latency to fall was longer in the blueberry group compared to the strawbe

tended to be higher than the control group (p=0.06). 

There was no effect of diet group on wire suspension, inclined screen, or any measure of plank walkin

Cognitive testing: 

ANOVA showed no effects of diet for either trial 1 or trial 2 performance on latency, distance, or speed

However, when separate t tests were performed between the two trial latencies for each diet, positive 

supplementation were observed. 

For latency to find the platform on days 3 and 4, the strawberry (p<0.05), and blueberry (p<0.01) group

differences between trial 1 and trial 2, i.e. trial 2 latencies were significantly less than trial 1. 

This one-trial learning was not found in the control group. For distance swam to the platform on days 3 and 4, similar results were found, strawberry (p<0.05), bl

showed significant improvements between trial 1 and trial 2, with trial 2 distances significantly less 

No significant improvement was seen in the control group. 
Appendix C. Evidence Tables 

Berry Evidence Tables – Animal / In Vitro Studies 

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Dopamine release: 

All striatal slices obtained from the animals in the various diet groups (6 animals per group) showed sig

oxotremorine-enhanced striatal dopamine release then that seen in those obtained from animals m

diet (control versus strawberry p<0.0001, control versus blueberry p<0.0001). 

Additional post hoc comparisons indicated that oxotremorine-enhanced dopamine release in the blueb

than that seen in the strawberry-fed (p<0.0001) group. 

GTPase activity: Age-induced decrements in carbachol stimulated GTPase activity were significantly less 

but not strawberry (p>0.05) than control. 

Oxidative stress: In the striatum, only the strawberry group (p<0.002) and blueberry (p<0.005) groups sho

protection than control group. 

Stawberry diet had greater 45Ca recovery (p<0.001), whereas the blueberry diet had lower recovery (p<0.

synaptosomes compared to the control diet. After treatment with 300 μM H2O2 only the blueberry grou

recovery (p<0.05) after treatment, i.e., a greater ability to extrude or sequester calcium after depolarizagroup. In fact, after exposure to H2O2 only the blueberry-fed diet group had no deficits in 45Ca recovery

Authors’ Conclusions Supplementation with the blueberry extract improved motor performance on 2 motor tests that rely on bal

These rats demonstrated one-trial learning, even with the 10 min retention interval. 

Quality A Limitations / Comments The amounts of strawberry and blueberry extracts added into the control diet were based on an equivalen

each diet provided equivalent antioxidant activity. 
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Author, Year Shukitt-Hale, 1999 

Central hypothesis/Stated Purposes of Study 

To determine the efficacy of dietary supplementation with antioxidants in reversing/restoring age-related d

performance in mice 

Hypothesis diagram Experimental diets or reagents 

Freeze-dried aqueous strawberry extract (1%) 

Control diets or reagents Modified AIN76 diet with 30 ppm Vit E Study characteristics Country: US 

Funding source: No data 

Gap in Knowledge Known: Oxidative stress (OS) is thought to be a contributing factor to the decrements in motor performanc

Antioxidant nutrients added to the diet are one defense strategy to prevent, intercept, or repair age-indglutathione (GSH), melatonin, and strawberry extract have all been found to have antioxidant propertie

Unknown: 

Experimental model Male C57BL.6NIA mice, 18 months of age before the dietary treatments. Study design Randomized control trial: weight matched mice were randomly assigned to 1 of 6 diet groups. 

An untreated group (n=11) of 4-month-old mice served as young, chow-fed, controls. 

Final sample size Weight-matched dataset: 

Control: 8 Strawberry: 10 

Duration 6 months Measurements / Endpoints / Outcomes of interest 

Behavioral testing: a battery of psychomotor behavioral tests was performed that consisted of complex mo

been shown to deteriorate with age. The tests included: 1) Rod walking, 2) Wire suspension/wire hangInclined screen 

Other outcomes reported Body weight Results For control rats only, several tests showed deficits from 4 to 18 months; however, no tests showed additio

decrements from 18 to 24 months. Specifically, in the rod walking test and wire-hang test, ANOVA shodifference (p<0.01); post-hoc testing showed that latency to fall was longer for the young group than fo

the 24-month group (p<0.01). Only data from the 4- and 24-month groups were comparable for the incthese group were tested at the 85o angle (60o angle proved too easy for the mice as they all achieved age or diet), there was a significant age effect on the inclined screen (p<0.01), with the 24-month-old a

latency to fall than the 4 –month-group. There were no age differences for plank walk latency, distance

There was no significant difference in the any parameter (when analyzing the weight-matched dataset) be

control animals. 

Authors’ Conclusions Although some deficits were seen from 4 to 18 months, motor performance for the 18-month group on all 

different from the 24-month group. 

Quality A Limitations / Comments To control for the difference in body weight and prevent its influence on the behavioral tests, subsequent A

subset of the animals by discarding mice with a weight of greater or less than 1 standard deviation awaall the mice. A total of 32 mice were eliminated from the analyses. 
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Author, Year Bickford, 2000 

Central hypothesis/Stated Purposes of Study 

Combinations of nutrients in foods with high antioxidant activity may reverse the age-related behavior

deficits in older rats. High antioxidant foods may improve cerebellar β-adrenergic receptor functionmotor learning in older rats. 

Hypothesis diagram Combinations of nutrients in foods with high antioxidant activity Æ ⁭ cerebellar β-adrenergic receptor fuExperimental diets or reagents 

Strawberry diet: control diet supplemented with strawberry extracts (14.8 g/kg dried aqueous extract) Blueberry diet: control diet supplemented with blueberry extracts (18.6 g/kg dried aqueous extract) 

Control diets or reagents Modified AIN-93 (Detailed composition listed in Table 1) Study characteristics Country: US 

Funding source: supported by the US Department of Agriculture, Veterans Administration Medical Re

Public Health Service 

Gap in Knowledge Known: Combinations of nutrients in foods with high antioxidant activity delay age-related behavioral 

in young rats. 

Unknown: Whether high anti-oxidant diet at a later age would reverse the age-related deficits in beha

receptor function in the cerebellum. 

Experimental model Male Fischer (F344) rat, 18 months of age Study design Parallel comparative study Final sample size 30 (14 control, 8 blueberry, 8 strawberry) Duration 8 weeks, from age 18 to 20 months Measurements / Endpoints / Outcomes of interest 

Motor learning: Time to cross runway of variably placed rods. 1) Actual time (% of initial running time)

(slope, rate of learning of the task). 

Extracellular electrophysiologic recordings of cerebellar Purkinje neurons for potentiation of GABAerg

adrenergic ISO (post-mortem) 

Other outcomes reported Total glutathione levels in the cerebellum (post-mortem) Results Motor learning: 

 1. No significant difference in asymptote (percent of initial running time after 10-14 days) between 

compared to control diets. 

 2. Trend toward faster learning (steeper decay constant [slope], p=0.15) in blueberry diet rats com

significant). (However, strawberry-fed rats were faster than controls at baseline, thus they did not have a steep 

Electrophysiologic recording: ISO potentiation of GABAergic inhibition in the cerebellum in observed i

percentage of neurons recorded from the blueberry- (p<0.001) and strawberry-fed (p<0.05) groups 

Authors’ Conclusions Diets high in antioxidants can improve performance on a motor learning task and reverse an age-indu

β-adrenergic receptor function. 

The improvement in speed during the first few days for the strawberry and blueberry fed rats might be 

psychomotor performance as opposed to improved motor learning; however an effect on learning 

session would not be detected. 

Further experiments are required to investigate the effects of the various phytochemicals found in the

Quality Limitations / Comments The amounts of strawberry and blueberry extracts added into the control diet were based on an equiv

that each diet provided equivalent antioxidant activity. 
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Author, Year Martin, 2000 

Central hypothesis/Stated Purposes of Study 

(1) to analyze the long-term (8 months) effect of low vitamin E in brain and other tissues; (2) to examine th

distribution following dietary vitamin E treatment; (3) to determine if low vitamin E intake could affect vicompensate for the vitamin E deficit; and (4) to determine function and attenuate the deleterious effectwithout affecting the concentrations of vitamins E and C 

Hypothesis diagram Antioxidants from fruits and vegetables Æ reduction of oxidative stress Æ prevention of neurodegenerativExperimental diets or reagents 

Strawberry exact (9.5 g/kg diet), [spinach (6.4 g/kg diet), or vitamin E (with 500-mg all-rac-α-tocopheryl ac

the control diet 

Control diets or reagents Modified AIN-93 Study characteristics Country: US 

Funding source: ND 

Gap in Knowledge Known: Age-related neurological deterioration is accompanied by a significant decrease of transmitter lev

neurotransmitter-synthesizing enzymes. 

Unknown: Antioxidants may play in preventing oxidative damage and their application in the prevention of 

diseases. 

Experimental model 6-month-old male Fischer 344 rats (Harlan Sprague Dawley, Indianapolis, IN) were used. When testing, a

15 months. 

Study design Following a 12-day acclimatization period to the facility, the 6-month-old male Fischer 344 rats (were weig

weeks on the control diet. They were then divided into 4 diet groups (control, strawberry extract, spina

E groups). [Note: for the purpose of this report, only control and strawberry extract groups are of intere

Final sample size Ctrl 20 

Strawberry 20 

Duration 8 months Measurements / Endpoints / Outcomes of interest 

Dopamine release 

Other outcomes reported Weight and food intakes 

Vitamins E and C levels in brain (hippocampus, cerebellum, and striatum), plasma, in liver, and in heart 

Results Diets enriched with extracts of strawberry showed enhanced dopamine release from striatal slices followin

stimulation by 100% compared to control (p<0.05) 

Authors’ Conclusions The observation that dopamine release induced by the diets containing strawberry was significantly enhan

diet is important, because brain tissues from control and experiment animals had very low vitamin E, c

vitamin-E group suggesting that other nutrients may be important for maintaining brain’s function. 

Quality B Limitations / Comments No behavioral or cognitive function outcomes 
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Author, Year Youdim, 2000

Central hypothesis/Stated Purposes of Study 

Blueberry supplementation diet prevents the cognitive decline through decreasing the susceptibility to 

benefits in peripheral systems. 

Hypothesis diagram 1) BB supplementation diet Æ decrease susceptibility to OS, ?dopamine release Æ decrease cognitive 

2) BB supplementation diet Æ increase aminotransferase (AST) activity - - - -> benefits in peripheral tis

Experimental diets or reagents 

Blueberry (BB) supplemented diets: 2% of the control diet was supplemented with either wild blueberry 

extract. Overall this was equivalent to the consumption of 4 g of BB (1 kg of whole BB yielded 110 g that rats consumed approximately 20 g diet/day). 

Control diets or reagents Control diet specification was described in Table 1 Study characteristics Country: US 

Funding source: ND 

Gap in Knowledge Known: Previous studies showed that rats maintained on diets enriched with strawberry or spinach ext

exhibited less age-related deficits in neuronal signal transduction and cognitive behavior impairmen

Unknown: If the beneficial effects can be observed when using a well-balanced chow diet that already 

of vitamin E, and which overall was more comparable with a normal balanced human diet. 

Working model 17-month Male Fisher 344 rats (Harlan Sprague Dawley, Indianapolis, IN) Internal standard 6-week run-in control chow diet Study design RCT of control, tif-blue blueberry (tif-BB) and wild blueberry (wild BB) diets. 15 rats per groups. Final sample size Control: 12 tif-BB:13 Wild-BB: 14 Duration 8 weeks Measurements / Endpoints / Outcomes of interest 

Age-sensitive tests of psychomotor behavior: 1) Rod walking, 2) Wire suspension, 3) Plank walking, 4) 

Accelerating rotarod 

Cognitive testing: Morris water maze, latency to find the platform, distance swam, and speed, were cal

Trials 1 and 2. Performance was assessed over 4 days (2 sessions/day, 2 trials/session) 

Dopamine release 

Other outcomes reported Erythrocyte ghost membrane fluidity 

RBC susceptibility to OS insult: dichlorofluorescein (DCFH-DA) assay Flavonoid extraction from plasma 

Results Tests of psychomotor behavior: 

Tif-BB Æ latency to fall was significantly longer compared to on the inclined screen (p=0.06) and th

no significant difference in the accelerating rotarod testing. 

Wild-BB Æ latency to fall was significantly longer compared to control on the accelerating rotarod (p

plank (p<0.05), but no significant difference in the inclined screen testing. 

 Morris water maze: 

Tif-BB Æ significantly lower latency to find the platform on Trial 1 (p<0.05) but the latency was not d

Wild-BB Æ no significant difference in the latency to find the platform on both Trial 1 and 2 

Dopamine release: Both Tif-BB (p<0.05) and Wild BB (p<0.05) supplemented animals showed signific

enhanced striatal dopamine release than control animals, but they were not differ from each other. 

Authors’ Conclusions Supplementation with the BB extract improved performance on motor tests, and enhanced striatal dop

Tif-BB supplementation improved reference memory performance (Trial 1 only), but not wild-BB supple

Quality A Limitations / Comments The effects on improving memory performance were weak. 
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Author, year Joseph, 2003

Central hypothesis/Stated Purposes of Study 

Blueberry supplementation may be of benefit in reducing the symptomology of Alzheimer’s disease (AD) 

Hypothesis diagram BB suppl Æ increase GTPase, decrease N-Sase, ?PKC; ?ERK Æ improve Y-maze performance; less Aβ Experimental diets or reagents 

Blueberry (BB) supplemented diet: 2% of the control diet was supplemented with BB extract from 4 month

age 

Control diets or reagents Control diet (modified NIH-31) specification was described in Table 1 Study characteristics Country: US 

Funding source: ND 

Gap in Knowledge Known: 1) significant reductions in muscarinic receptor –G protein signaling as a function of AD and aging

sphingomyeline-specific PLC (N-Sase) activity with age 

Unknown: other signaling parameter associated with aging, e.g. calcium-dependent protein kinase C (PK

regulated kinase (ERK) 

Experimental model Mice transgenic for amyloid precursor protein (APP) and presenilin-1 (PS1) mutations. These mice are pr

in cerebral cortex and hippocampus early in the life-span with later changes in cognitive behavior 

Study design Transgenic vs. non-transgenic mice (CTR-N), both groups on either blueberry diet (BB) or control diet (CoFinal sample size Transgenic BB 3 CTR-N BB 7 

Transgenic Control 3 CTR-N Control 8 

Duration 12 months Measurements / Endpoints / Outcomes of interest 

Y-maze performance Fibrillar Aβ deposits in the brain Brain neutral sphingomyelin-specific phospholipase C (N-Sase) activity Brain low Km GTPase activity Brian calcium-dependent protein kinases (PKC) activity: protein kinase Cγ (PKCγ); phospho-protein kinas

Brian extracellular regulated signal kinases (ERK) activity 

Other outcomes reported Results BB supplementation had a beneficial effect on Y-maze performance in transgenic mice, as demonstrated 

alternation behavior [p<0.05] 

There is no significant difference I the Y-maze performance between the wild-type mice fed blueberry die

diet. 

BB supplemented transgenic mice had no change on Aβ deposits in the brain 

BB supplementation significantly increased the low Km GTPase activity (p<0.05) in striatum but not in hip

transgenic animals compared to the respective controls. No significant effects of BB supplementation 

transgenic animals. Positive correlation between GTPas activity and Y-maze alternation in the striatum hippocampus or cortex 

BB supplementation significantly decreased N-Sase activity for both transgenic animals (p<0.01) and con

striatum, hippocampus, and the cortex. Negative correlation between N-Sase activity and Y-maze altenot in the hippocampus or cortex 

BB supplementation increased hippocampal ERK activity in the transgenic mice (p<0.001). Other brain re

Correlation between hippocampal ERK activity and Y-maze alternation did not reach significance. 

The levels of PKCγ were unaffected by the transgenic condition or the diet (data not shown) in any of the 

and the correlations between this parameter and Y-maze alternation were not significant. 

BB supplementation increased hippocampal phospho-PKCα activity in the transgenic mice (p<0.05). No d
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other brain areas among the various groups. Correlational analyses with Y-maze performance revealesignificance in the hippocampus (p=0.09) 

Authors’ Conclusions BB suppl Æ increase GTPase (yes in striatum, p<0.05), decrease N-Sase (yes in striatum and hippocam

effect); ERK (increase in hippocampus, p<0.01) Æ improve Y-maze performance (yes, p<0.05); less A

(no) 

Although BB supplementation did not affect Aβ deposits, the supplementation seemed to have prevented 

performance seen in the transgenic animals fed the control diets. 

Quality A Limitations / Comments Transgenic mice should have lower Y-maze performance, lower GTPase activity, higher N-Sase activity c

when feeding control diet (data were shown). 

Correlate the “intermediate markers” to the neurocognitive measures! 
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Author, Year Casadesus, 2004 

Central hypothesis/Stated Purposes of Study 

To examine whether neurogenesis, growth factors, and mitogen-activated protein-kinase (MAPK), in com

were associated with improvements in hippocampally-dependent cognitive output in aged blueberry-su

Hypothesis diagram Blueberry supplementation Æ ? neurogenesis, ? growth factors ? MAPK Æ improve cognitive output Experimental diets or reagents 

Blueberry extract diet: 2% of the control diet was supplemented with blueberry extract. Overall this was eq

consumption of 4 g of BB (1 kg of whole BB yielded 110 g of BB extract, assuming that rats consumed diet/day). 

Control diets or reagents NIH-31 20g/kg Study characteristics Country: US 

Funding source: No data 

Gap in Knowledge Known: Dietary fruit and vegetable supplementation appear to forestall or reverse various age-related neu

Unknown: The mechanisms responsible for behavioral and neuronal changes seen during aging are not f

Experimental model 19-month-old male F344 rats (Harlan Sprague-Dawley, Indianapolis, IN) Study design RCT Final sample size 10 in total (assumed 5 per group) Duration 8 weeks Measurements / Endpoints / Outcomes of interest 

Radial Arm Water Maze (RAWM) performances: rats were tested for 5 consecutive days. The order of en

recorded so that the number of errors could be analyzed. The errors recorded were reference (long-ter(defined as entering an arm that disen’t contain the platform) and working (short-term) memory errors 

entering an already visited arm whether or not it contained the platform). Total memory errors refer to t

and working memory errors. 

Neurogenesis in the rat brain: bromodeoxyuridine (BrdU) incorporation into the nuclei of dividing cells and 

marker primary antiglial fibrillary acidic protein (GFAP) antibody to exclude the presence of glial BrdU l

Hippocampus growth factors, such as IGF-1 and IGF-1R levels, and extracellular-signal-regulated-kinase 

Other outcomes reported Results RAWM performances: 

Repeated measures analysis across days revealed a significant day effect for latency (p<0.0001) sugg

groups could successfully learn the task on days 1-3. The lack of interaction between groups (p<0.7

rate of learning on days 1-3 did not differ across groups. On day 4, compared to animals fed the co

rats had significantly fewer reference memory errors (p<0.05) and total memory errors (p<0.05), antowards fewer working memory errors (p<0.06). No significant difference in RAWM performances won day 5. 

Neurogenesis: 

Short-term blueberry supplementation significantly increased proliferation of precursor cells in the dent

(p<0.05). Pearson’s correlations revealed that, as the number of proliferating cells increased, the nu

on Day 4 decreased (reference memory errors: r=-<0.684, p<0.05; working memory errors: r=-<0.6

errors: r=-<0.677, p<0.05). 

IGF-1 and IGF-1R levels: 

A significant increase in the levels of IGF-1 protein by blueberry supplementation compared to the con

Increased IGF-1 levels were associated with significant decreases in memory errors (total memory 

and trends towards decreased reference memory errors (r=-0.539, p<0.09) and working memory er

There was a statistically significant positive correlation between ERK activation and IGF-1 levels (r=0.7

There were no significant correlations between levels of IGF-1 and proliferation. 
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Levels of IGF-1R in blueberry-supplemented rats were significantly increased compared to the control 

correlated with levels of IGF-1 (r=0.788, p<0.01). The increase in IGF-1R were associated with decerrors (r=-0.375, p<0.05) and reference memory errors (r=0.738, p<0.01) but not working memory eon day 4. 

There was a statistically significant positive correlation between ERK activation and IGF-1R levels (r=0

proliferation. 

ERK activation: 

There was a significant increase of ERK activation by blueberry supplementation (p<0.01). The increas

related to decreases in total memory errors (r=-0.629, p<0.05) and reference memory errors (r=-0.6working memory errors (r=-0.537, p<0.109) on day 3. Proliferation was not significantly correlated w

Authors’ Conclusions Blueberry supplementation Æ increase IGF-1, IGF-1R, and ERK activation Æ decreases in total memory 

memory errors but NOT working memory errors on day 4 

Increase IGF-1, IGF-1R, and ERK activation are NOT associated with neurogenesis Blueberry supplementation Æ increased proliferation of precursor cells in the dentate gyrus of aged rats Æ 

memory errors, reference memory errors, and working memory errors 

Quality A Limitations / Comments Correlate the “intermediate markers” to the neurocognitive measures! 
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Author, Year Goyarzu, 2004

Central hypothesis/Stated Purposes of Study 

(1) Aged rats on control diet will be impaired in object recognition memory, (2) The age-related impairmen

a longer delay between object presentation and preference testing (maximizing memory demand), (3) 

will have elevated cytosolic NF-kB levels in several brain regions, (4) For months of diet supplementat

blueberry extract will significantly reduce both the age-related memory impairment and the elevation o

Hypothesis diagram Supplementation of blueberry extract Æ reduced the elevation of NF-kB (a indicator of oxidative stress) Æ 

memory impairment 

Experimental diets or reagents 

2% blueberry supplemented to NIH-31 rodent chow. 200 g/week. 

Control diets or reagents 2% dried corn supplemented to NIH-31 rodent chow. 200 g/week. Study characteristics Country: US 

Funding source: University funded 

Gap in Knowledge Known: The protein transcription factor, nuclear factor-kappa B (NF-kB) is a highly responsive indicator of 

Increased NF-kB activity may constitute a protective response, buffering the effects of OS as induction mitochondrial dysfunction. 

Unknown: 

Experimental model Aged subjects: 15-month-old male virgin Fischer-344 rats (19-months old at time of testing) 

Young subjects: 4-month-old male virgin Fischer-344 rats (8-months old at time of testing) 

Study design For 4 months prior to testing, 12 young rats were maintained on the control diet. 12 aged rats were mainta

while 12 aged rats were fed the BB-supplemented diet. 

Final sample size Young Ctrl: 12 Aged Ctrl: 12 Aged BB: 12 Duration 4 months Measurements / Endpoints / Outcomes of interest 

Object recognition memory: Ennaceur and Delacour (1988) introduced a non-spatial object recognition m

recognition memory for having previously encountered and explored an object. The procedure exploits 

rats to preferentially explore novel vs. familiar objects. Young rats spend much more time closely explo

the familiar object. 

NF-kB levels in the brain: 4 days after the conclusion of behavioral testing, subjects were perfused with sa

removed and dissected into 3 different regions, including the frontal cortex, hippocampus, basal forebrcerebellum. 

Other outcomes reported Weight gain Results Object recognition memory: 

All 3 groups showed significantly greater than chance preference for the novel object with a 30-s traini

the young rats and the BB diet aged rats with a 1-h delay. 

Pair-wise post-hoc comparisons (Fisher’s LSD test) of object recognition scores after the 30-s delay re

differences among the 3 groups. 

Pair-wise post-hoc comparisons of object recognition scores after the 1-h delay revealed that young ra

object recognition memory scores than aged rats on the control diet (p<0.01). The blueberry-supple

had significantly higher object recognition memory scores than aged rats on the control diet (p<0.0

difference between the young rats and the blueberry-supplemented aged rats. 

NF-kB levels in the brain: 

In every region, aged rats maintained on the control diet had higher NF-kB levels than young rats main

In every region, aged rats maintained on the BB-enriched diet had lower NF-kB levels than aged rats m

diet. In all regions except the basal forebrain, this difference was significant. 
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In the cerebellum, the aged rats maintained on the BB-enriched diet had significantly higher NF-kB lev

However, in the other 4 regions, there was no significant difference between those 2 groups. 

Authors’ Conclusions Blueberry supplementation eliminated the deficit in 19-month old rats, in that the aged the aged blueberry

only performed significantly above chance, but also performed as well as young rats. 

Blueberry supplementation attenuates the elevation of NF-kB levels in the aging rat brain. 

Quality A Limitations / Comments 
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Author, Year 

Joseph, 2004 

Central hypothesis/Stated Purposes of Study 

Blueberry and other fruit extracts may provide protection against Aβ 25-35 or dopamine (DA) in the COS-

Hypothesis diagram Fruit extracts Æ reduce Aβ (25-35)- or DA- induced oxidative stress (OS ) through MAChRs Experimental diets or reagents 

2 mg/ml blueberry (BB), 2 mg/ml black currant (BC), 2 mg/ml boysenberry (BY), or 0.5 mg/ml strawberry (

(CB) pre-treatments 

Control diets or reagents No pre-treatments Study characteristics Country: US 

Funding source: No data 

Gap in Knowledge Known: The effects of OS may occur at the receptor level. In this respect, experiments have shown that th

in MAChRs as a function of age and AD, as well as aging. Recent findings have shown that COS-7 ce

the 5 MAChRs and exposed to DA showed differences in OS sensitivity in calcium buffering. In 2 previshown that antioxidants can prevent the loss of viability in COS-7 cells transfected with sensitive (M1A

and exposed to DA, and prevent the decrease in Recovery in M1AchR-transfected COS-7 cells expose

Unknown: if similar protection (described above) could be achieved against Aβ (25-35, 100 μM) or DA exp

transfected COS-7 cells following pre-treatment with various fruit extracts that have high antioxidant ac

Experimental model COS-7 cells (ATCC) transfected with rat muscarinic receptor subtype 1 or 3 DNA by the DEAE-dextran mStudy design In vitro: Each fruit extract was dissolved in growth media and M1AchR-transfected COS-7 cells were subs

min at 37 °C with the treated growth medium. Following these incubations the cells were washed 3 tim

medium prior to testing. Note that no repeated measures were utilized in these studies. 

Final sample size N/A Duration N/A Measurements / Endpoints / Outcomes of interest 

Ca2+ Recovery following 0 or 1 mM DA treatment: Recovery was determined by assessing the time (within 

level to return to 20% of the increase following depolarization in the cells that responded. 

Ca2+ Recovery following 0 or 100 μM Aβ (25-35) treatment 

% Viability following 0 or 1 mM DA treatment: Viability of the cell at 24 hrs following a 4 hr exposure to 1 m

using the Live/Dead Eukolight Viability/Cytotoxicity Kit (Molecular Probes, Eugene, OR) without detach

mm plates. 

Other outcomes reported Results In the absence of pre-treatment (control condition) there were significant effects of both DA and Aβ on Re

transfected cells (e.g., control vs. DA- or Aβ-treated cells with no extract pre-treatment, p<0.001). 

In comparisons with the non-preteated DA-exposed cells, all of the fruit extract pre-treatments were effect

protection. However, compared to their own respective controls (not exposed to DA) only BB, and BY wagainst the DA. 

The BB-pre-treatment was the most effective in protecting against the effects of Aβ on Recovery (e.g., BB

p>0.05; BB+Aβ vs. control, p>0.05; BB+Aβ vs. Aβ, p<0.05). 

The Recovery in the BC+Aβ cells did not differ from their respective controls (p>0.05), while the cells pre-

exposed to Aβ showed lower Recovery than their respective controls (p<0.05). 

SB did not offer protection against Aβ and the cell exposed to Aβ and pre-treated with SB showed lower R

respective controls (p<0.05). 

BB and BY showed the strongest effects in protecting the DA-treated cells against loss of viability (e.g., B
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non-BB-treated, p>0.05). The effects of the other extracts (i.e., CB, BC, and SB) were similar except th

pre-treated with these extracts showed lower viability than that seen in their respective non-DA treated 

Authors’ Conclusions The results from the present study indicate that it may be possible to reduce both the deleterious effects o

effects of Aβ via fruits high in antioxidant activity. Each of these fruit extracts showed some degree of pdeleterious effects of DA on Recovery, with SB showing the weakest effects. The most efficacious extrwhich were totally protective against the effects of DA, as compared to their own respective controls. 

BB pre-treatment was also the most beneficial in protecting against the effects of Aβ on Recovery, while, 

with DA, BC exceeded those of BY and GR effects were negative. As with DA exposure, SB showed v

against Aβ on Recovery. 

In the case of Viability, the M1-transfected COS-7 cells showed similar effects to that seen with respect to 

BY showing the strongest effects. 

Quality B Limitations / Comments The study also had 0.5 mg/ml dried plum and 0.05 mg/ml grape (GR) pre-treatments but they are not of in

that no repeated measures were utilized in these studies. 
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Author, Year Rabin, 2005A 

Central hypothesis/Stated Purposes of Study 

To evaluate the effects of strawberry and blueberry supplementation on operant performance in rats expo

particles. Specifically, (1) would antioxidant diets be equally effective following exposure to a higher do

which presumably produce a greater level of oxidative stress? (2) What would be the nature of the inteanimal at the time of testing? 

Hypothesis diagram Heavy particle irradiation Æ neurobehavioral deficits due to accelerated oxidative stress. Berry antioxidanExperimental diets or reagents 

Blueberry (BB) diet: 2% of the control diet was supplemented with blueberry extract. Overall this was equ

of 4 g of BB (1 kg of whole BB yielded 110 g of BB extract, assuming that rats consumed approximate

homogenate replaced corn in NIH-31 diet. 

Strawberry (SB) diet: 2% of the control diet was supplemented with strawberry extract. 

Control diets or reagents NIH-31 Study characteristics Country: US 

Funding source: National Aeronautics and Space Administration (NASA) 

Gap in Knowledge Known: Exposure to heavy particles such as 56Fe produces deficits in neurobehavioral function which are 

organism. 

Unknown: Whether high anti-oxidant diet, in the form of blueberries or strawberries, can mitigate effect of 

Experimental model Male Sprague-Dawley rats weighing 175-200 g Study design Rats were placed on a diet containing blueberry extract, or strawberry extract, or on a control diet for 2 mo

The rats were irradiated with 1.5 Gy of 56Fe. After exposure the rats were trained and tested on the op

After exposure, all rats were placed on non-berry supplement diets. 

Final sample size BB+56Fe: 10 SB+56Fe: 10 Ctrl+56Fe: 10 

BB: 10 SB: 10 Ctrl: 10 Several rats, particularly among those irradiated & on control diet, were euthanized before completion due 

Duration 12 months after irradiation Measurements / Endpoints / Outcomes of interest 

Operant task: The rats were food deprived to 85%-90% of their base weight and trained to lever press for 

an autoshaping procedure, which was followed by training to respond on an Fixed-Ratio (FR) reinforce

response had been acquired, the rats were immediately tested on an ascending FR schedule for FR-1 

were carried out at 6 and 12 months postirradiation. 

Other outcomes reported Results When tested 6 months after irradiation, all groups, irrespective of diet or irradiation status performed equa

At 12 months after irradiation, irradiated rats fed strawberries performed equally well as non-irradiated rat

blueberries or control diet performed equally poorly compared to the other groups. 

Authors’ Conclusions Disruption of operant performance (specifically response to an ascending fixed ratio schedule) by heavy p

rats can be prevented by maintaining rats on a diet containing 2% strawberry extract, but not blueberry 

Lack of difference among diets and radiation status at 6 months was expected from previous research ind

effects of exposure to 1.5 Gy of 56Fe particles occurs among older rats. 

Quality A Limitations / Comments Unclear whether exposure to heavy particles is an appropriate model for human neurocognitive disease w

Medline UI 15725409 
Appendix C. Evidence Tables 

Berry Evidence Tables – Animal / In Vitro Studies 

C-281 

Author, Year Rabin, 2005B 

Central hypothesis/Stated Purposes of Study 

To evaluate the effects of strawberry and blueberry supplementation on operant performance in rats expo

particles. Specifically, (1) would antioxidant diets be equally effective following exposure to a higher do

which presumably produce a greater level of oxidative stress? (2) Would the previously obtained differ

of the strawberry diet compared to the blueberry diet be observed in an independent experiment using radiation? (3) What would be the nature of the interaction with the age of the animal at the time of testi

Hypothesis diagram Heavy particle irradiation Æ neurobehavioral deficits due to accelerated oxidative stress. Berry antioxidanExperimental diets or reagents 

Blueberry (BB) diet: 2% of the control diet was supplemented with blueberry extract. Overall this was equ

of 4 g of BB (1 kg of whole BB yielded 110 g of BB extract, assuming that rats consumed approximate

Strawberry (SB) diet: 2% of the control diet was supplemented with strawberry extract. 

Control diets or reagents NIH-31 Study characteristics Country: US 

Funding source: National Aeronautics and Space Administration (NASA) 

Gap in Knowledge Known: Exposure to heavy particles such as 56Fe produces deficits in neurobehavioral function which are 

organism. Deleterious effects mitigated by X diet after 1.5 Gy irradiation 

Unknown: Effect of berry diets after higher dose irradiation. 

Experimental model Male Sprague-Dawley rats weighing 175-200 g Study design Rats were placed on a diet containing blueberry extract, or strawberry extract, or on a control diet for 2 mo

The rats were irradiated when they were about 3.5 to 4.0 months of age with 2.0 Gy of 56Fe. Following 

trained and tested on the operant task. 

After exposure, the rats were fed a diet of standard lab chow (Purina 5100). 

Final sample size BB+56Fe: 8 SB+56Fe: 8 Ctrl+56Fe: 8 

BB: 4 SB: 4 Ctrl: 8 Several rats, particularly among those irradiated & on control diet, were euthanized before completion due 

Duration 18 months after irradiation Measurements / Endpoints / Outcomes of interest 

Operant task: The rats were food deprived to 85%-90% of their base weight and trained to lever press for 

an autoshaping procedure, which was followed by training to respond on an Fixed-Ratio (FR) reinforce

response had been acquired, the rats were immediately tested on an ascending FR schedule for FR-1 

were carried out: 5, 8, 13 and 18 months postirradiation. 

Other outcomes reported Results Significant interactions were found between diet (combined berry vs control), irradiation (vs non-irradiation

time (5, 8, 13, and 18 months after irradiation and initial training, i.e., age). 

When tested 5 and 8 months after irradiation (9 and 12 months of age), irradiated rats fed strawberries pe

non-irradiated rats. Irradiated rats fed blueberries or control diet performed equally poorly compared to 

At 13 and 18 months after irradiation, there was a decrement in the performance of the irradiated rats con

compared to those on the blueberry diet; although their performance remained somewhat better. Com

on control diet could not be made because all but 2 of these animals died. 

Authors’ Conclusions Disruption of operant performance (specifically response to an ascending fixed ratio schedule) by heavy p

prevented by maintaining rats on a diet containing 2% strawberry extract, but not blueberry extract. 

Similar to previous results found with exposure to 1.5 Gy of 56Fe, except that difference between diets is f

Quality A Limitations / Comments Unclear whether exposure to heavy particles is an appropriate model for human neurocognitive disease w

Not in Medline or CAB abstracts 
Appendix C. Evidence Tables 

Berry Evidence Tables – Animal / In Vitro Studies 

C-282 

Author, Year Shukitt-Hale, 2005 

Central hypothesis/Stated Purposes of Study 

To determine whether the beneficial effects of blueberries would also be seen with other berry fruits as com

Hypothesis diagram Experimental diets or reagents 

2% of the control diet was supplemented with blueberry (BB), blackcurrant (BC), boysenberry (BS) or cranb

anthocyanin and total phenolic concentration present in the extracts are as blow: 

Berryfruit type Total anthocyanin concentration 

(mg/g) 

Total phenolic (325 nm) concentration 

(mg/g) 

Blueberry 1.3 1.2 Blackcurrant 8.7 2.9 Boysenberry 9.2 2.0 Cranberry 3.3 3.6 

Control diets or reagents 

NIH-31 (20 g/kg) 

Study characteristics Country: US 

Funding source: USDA, Cranberry Institute; The Horticulture and Food Research Institute of New Zealand 

Gap in Knowledge Known: Previous studies have shown that increasing the levels of inducible hippocampal heat shock protein 

cells from numerous insults ranging from ischemia, inflammatory agents and reactive oxygen species. 

Unknown: The loss of the ability of cells to respond to these insults by increasing HSP70 may contribute to 

both neuronal and behavioral functioning. 

Experimental model 19-month-old Male Fischer 344 rats Study design Weight-matched rats were placed on 3 separate diets (BB, BC, BS, CB or control diets) for 13-16 weeks totFinal sample size No data Duration 13-16 weeks Measurements / Endpoints / Outcomes of interest 

Psychomotor testing, including (1) Rod Walk, (2) Wire Suspension, (3) Plank Walk, (4) Inclined Screen; (5) 

Morris Water Maze (MWM), an accepted method of testing spatial learning and memory, is an age- and die

paradigm that requires rats to find the location of a hidden platform just below the surface of a circular po

cues in previous learning trials. 

Hippocampal heat shock protein 70 (HSP70): in vitro LPS (Lipopolysaccharide) treatment (a stressor) 

Dopamine release 

Other outcomes reported Results Of the psychomotor testing, only the inclined screen yielded significant results between diet groups. BB (p=

groups performed significantly better than the control group. 

Morris Water Maze performance showed no differences among the diet groups. Dopamine release was different among the groups. Post-hot testing found that the BC (p=0.004) and CB (p

significantly better than the control and BS groups. The effects of BB supplementation on striatal dopam

this study, since it had been replicated in previous studies. 

Percent change in HSP70 also showed differences among the groups. Post-hot analyses showed that HSP

BB group was significantly higher than the control group (p=0.001), which the CB group showed a trend the control group (p=0.06). Furthermore, HSP70 levels positively correlated with inclined screen perform

from the inclined screen increased as the percent change in HSP70 increased (r=0.39, p=0.048) 
Appendix C. Evidence Tables 

Berry Evidence Tables – Animal / In Vitro Studies 

C-283 

Authors’ Conclusions There were significant effects of the diets found on several of the measures in this study. The inclined scree

HSP70 results all suggest that there is a range of effectiveness associated with the different berryfruit dieappear that the anthocyanin component is the one solely responsible for these improvements, as the bla

boysenberry fruits are higher in anthocyanin level, but not as effective in improving motor performance. Fexamine other components, such as the proanthocyanidins and flavans,, in addition to the anthocyanins

Quality B Limitations / Comments Sample size was not reported. 
Appendix C. Evidence Tables 

Berry Evidence Table – Human Studies 

C-284 

Berry Evidence Tables – Human Studies 
Appendix C. Evidence Tables 

Berries-Human Studies 

C-285 

Author, Year: Golbe, 1988 Ref ID: 15294 Berries 

/Constituents: 

Blueber

Objective: To examine the hypothesis that Parkinson’s disease may be cased by an amino acid chemically related to L-β-methyl-

or more fruits and vegetables common in the Western diet. 

Study characteristics Population Controls Inclusion 

criteria 

Exclusion criteria Definitio

Case-control study 

Age: 62.3±9.2 62.0±9.8 Cases: Cases-control pairs: 

Comparative %Male: 59.3 59.3 

Study design AD: 

Retrospective Race: ND ND 

PD patients

PD: A diagnoconfirmed specializi

Country: US Other: Controls: 

Either member was not married before age 40 years or was demented. 

VascDz: 

Setting: Outpatients Other: Funding: ND 

Same-sex siblings of the cases who were nearest in age and willing and able to cooperate 

Comments: Predictor(s): Outcome(s): Total Population of 

N enrolled: 162 81 

More or less N analyzed: 162 81 likely to consume a food (a list of fruits & vegetables) 

P>Sib if P>Sp and Sib<SibSp; P>Sp and SibN; P=Sp and Sib<SibSp; or p=Sp and SibN. P<Sib if P<Sp and Sib>SibSp; PN and Sib>SibSp;P<Sp and Sib=SibSp, or PN and Sib=SibSp. 

OR of PD in those more likely to eat the food to those less likely to eat the food 

MantelHaenszel method 

Drop-outs (%): N/A 
Appendix C. Evidence Tables 

Berries-Human Studies 

C-286 

Comments: Patients and same-sex siblings, in separate interviews, were each asked whether they or their spouse was more likely to 

time of marriage and age 40 ages. The spouses of patients and same-sex siblings were also interviewed for their dietastandard. 

A reliability research of the method was conducted before the study in 15 patients with PD and their spouses. An item w

than 70% the pairs agreed on which member was more likely to eat that food item. 

Other predictors/outcomes reported (if applicable): Follow-up duration (if applicable): Reasons for drop out (if applicable): Limitations: Unusual definition of the consumption levels. Too many potential measurement errors due to the study and survey-me

observations should be due to random errors. 

Quality (A/B/C): C Applicability (1/2/3): 2 Outcome(s): Results (Text) OR of PD There was no significant association between preference for consuming blueberries or strawberries and the risk Case-Control Pairs Discordant for Preference (Relative to Spouse) for Various Fruits and Vegetables  Pt>Sib Pt<Sib Odds Ratio P Blueberries 13 21 0.62 NS Strawberries 5 12 0.42 NS *see “Predictors” for the definitions for Pt>Sib and Pt<Sib Keys: P>Sp, patient more likely than spouse to eat item; P=Sp, patient as likely as spouse to eat item and both dipatient less likely than spouse to eat item; PN, neither the patient nor spouse ate item. Sib>SibSp, sibling more li

own spouse to eat item; Sib=SibSp, sibling as likely as spouse to eat item and both did eat item; Sib<SibSp, siblispouse to eat item; SibN, neither the sibling nor his or her spouse ate item. 
D-1 

Appendix D. List of Excluded Studies 

Abd ElGawad HM, Khalifa AE. Quercetin, coenzyme Q10, 

and L-canavanine as protective agents against lipid 

peroxidation and nitric oxide generation in endotoxininduced shock in rat brain. Pharmacol Res. 2001;43(3):257-

63. Non-berry chemical 

Abe T, Itokawa Y. Effect of ethanol administration on 

thiamine metabolism and transketolase activity in rats. Int J 

Vitam Nutr Res. 1977;47(4):307-14. No outcome of 

interest 

Abe T, Okamoto E, Itokawa Y. Biochemical and 

histological studies on thiamine-deficient and ethanol-fed 

rats. J Nutr Sci Vitaminol. 1979;25(5):375-83. No outcome 

of interest 

Adachi K, Izumi M, Osano Y, Miura N, Takatsu S, Terao 

S, Mitsuma T. Polyamine concentrations in the brain of 

vitamin B12-deficient rats. Exp Biol Med. 

2003;228(9):1069-71. No outcome of interest 

Agbayewa MO, Bruce VM, Siemens V. Pyridoxine, 

ascorbic acid and thiamine in Alzheimer and comparison 

subjects. Can J Psychiatry. 1992;37(9):661-2. N<50 (Food 

frequency questionnaire) 

AhmadAnnuar A, Tabrizi SJ, Fisher EM. Mouse models as 

a tool for understanding neurodegenerative diseases. Curr 

Opin Neurol. 2003 ;16(4):451-8. Review 

Aikawa H, Suzuki K, Iwasaki Y. Ultrastructural 

observation on the thalamic neuronal inclusions in young 

mice. Acta Neuropathol. 1983;59(4):316-8. B vitamin 

antagonist 

Akaike A, Tamura Y, Sato Y, Yokota T. Protective effects 

of a vitamin B12 analog, methylcobalamin, against 

glutamate cytotoxicity in cultured cortical neurons. Eur J 

Pharmacol. 1993;241(1):1-6. No outcome of interest 

Almaas R, Saugstad OD, Pleasure D, Rootwelt T. Neuronal 

formation of free radicals plays a minor role in hypoxic cell 

death in human NT2-N neurons. Pediatr Res. 

2002;51(2):136-43. Non-berry chemical 

Almeida OP, Flicker L, Lautenschlager NT, Leedman P, 

Vasikaran S, van Bockxmeer FM. Contribution of the 

MTHFR gene to the causal pathway for depression, anxiety 

and cognitive impairment in later life. Neurobiol Aging. 

2005;26(2):251-7. All normal cognition (correlation study) 

Amanpreet S, Naidu PS, Kulkarni SK. Quercetin 

potentiates L-dopa reversal of drug-induced catalepsy in 

rats: possible COMT/MAO inhibition. Pharmacology. 

2003. Non-berry chemical 

Anderson C, Checkoway H, Franklin GM, Beresford S, 

SmithWeller T, Swanson PD. Dietary factors in Parkinson's 

disease: the role of food groups and specific foods. Mov 

Disord. 1999;14(1):21-7. Fruit, not berry 

Andersson J, Gustafsson K, Fjellstrom C, Sidenvall B, 

Nydahl M. Five-day food intake in elderly female 

outpatients with Parkinson's disease, rheumatoid arthritis or 

stroke. J Nutr Health Aging. 2005. No comparison group 

(Food frequency questionnaire) 

ArmstrongJames M, Ross DT, Chen F, Ebner FF. The 

effect of thiamine deficiency on the structure and 

physiology of the rat forebrain. Metab Brain Dis. 

1988;3(2):91-124. No outcome of interest 

Bambauer HJ, Ueno S, Umar H, Ueck M. 

Ultracytochemical localization of Ca++-ATPase activity in 

pituicytes of the neurohypophysis of the guinea pig. Cell 

Tissue Res. 1984;237(3):491-7. Non-berry chemical 

Barbato M, Rodriguez PJ. Thiamine deficiency in patients 

admitted to a palliative care unit. Palliat Med. 

1994;8(4):320-4. Ineligible population (and/or no subanalysis of age-related neurocognitive disease) 

Beal MF, Henshaw DR, Jenkins BG, Rosen BR, Schulz JB. 

Coenzyme Q10 and nicotinamide block striatal lesions 

produced by the mitochondrial toxin malonate. Ann 

Neurol. 1994;36(6):882-8. Wrong model (mitochondrial 

defect) 

Bell IR, Edman JS, Marby DW, Satlin A, Dreier T, Liptzin 

B, Cole JO. Vitamin B12 and folate status in acute 

geropsychiatric inpatients: affective and cognitive 

characteristics of a vitamin nondeficient population. Biol 

Psychiatry. 1990;27(2):125-37. N<30 dementia (B12 or 

Folate correlation) 

Bell IR, Edman JS, Miller J, Hebben N, Linn RT, Ray D, 

Kayne HL. Relationship of normal serum vitamin B12 and 

folate levels to cognitive test performance in subtypes of 

geriatric major depression. J Geriatr Psychiatry Neurol. 

1990;3(2):98-105. N<100 (B12 or Folate correlation) 

Bettendorff L, Hennuy B, De Clerck A, Wins P. Chloride 

permeability of rat brain membrane vesicles correlates with 

thiamine triphosphate content. Brain Res. 1994;652(1):157-

60. No outcome of interest 

Bettendorff L, Hennuy B, Wins P, Schoffeniels E. Thiamin 

and derivatives as modulators of rat brain chloride 

channels. Neuroscience. 1993;52(4):1009-17. No outcome 

of interest 
D-2 

Bettendorff L, Kolb HA, Schoffeniels E. Thiamine 

triphosphate activates an anion channel of large unit 

conductance in neuroblastoma cells. J Membr Biol. 

1993;136(3):281-8. No outcome of interest 

Bettendorff L, Mastrogiacomo F, Wins P, Kish SJ, Grisar 

T, Ball MJ. Low thiamine diphosphate levels in brains of 

patients with frontal lobe degeneration of the nonAlzheimer's type. J Neurochem. 1997;69(5):2005-10. 

Ineligible population (and/or no sub-analysis of age-related 

neurocognitive disease) 

Bettendorff L, Wins P, Schoffeniels E. Regulation of ion 

uptake in membrane vesicles from rat brain by thiamine 

compounds. Biochem Biophys Res Commun. 

1990;171(3):1137-44. No outcome of interest 

Bhagavan HN, Stewart CN. Tissue pyridoxal-5'-phosphate 

content and avoidance behavior in 2-deoxypyridoxinetreated rats. Int J Vitam Nutr Res. 1974. B vitamin 

antagonist 

Bhattacharya R, Lakshmana Rao PV. Pharmacological 

interventions of cyanide-induced cytotoxicity and DNA 

damage in isolated rat thymocytes and their protective 

efficacy in vivo. Toxicol Lett. 2001;119(1):59-70. Nonberry chemical 

Bickford P. Motor learning deficits in aged rats are 

correlated with loss of cerebellar noradrenergic function. 

Brain Res. 1993;620(1):133-8. Non-berry 

Botez MI, Botez T, Maag U. The Wechsler subtests in mild 

organic brain damage associated with folate deficiency. 

Psychol Med. 1984;14(2):431-7. Ineligible population 

(and/or no sub-analysis of age-related neurocognitive 

disease) 

Bottiglieri T, Parnetti L, Arning E, Ortiz T, Amici S, Lanari 

A, Gallai V. Plasma total homocysteine levels and the 

C677T mutation in the methylenetetrahydrofolate reductase 

(MTHFR) gene: a study in an Italian population with 

dementia. Mech Ageing Dev. 2001;122(16):2013-23. 

N<100 (B12 or Folate correlation) 

Brown I. Does diet protect against Parkinson's disease? Part 

3 - Fruit, vegetables and grains. Nutr Food Sci. 2004. 

Review 

Bunce D, Kivipelto M, Wahlin A. Apolipoprotein e, B 

vitamins, and cognitive function in older adults. J Gerontol 

B Psychol Sci Soc Sci. 2005;60(1):P41-8. All normal 

cognition (correlation study) 

Bunce D, Kivipelto M, Wahlin A. Utilization of cognitive 

support in episodic free recall as a function of 

apolipoprotein E and vitamin B12 or folate among adults 

aged 75 years and older. Neuropsychology. 

2004;18(2):362-70. All normal cognition (correlation 

study) 

Buxton PK, Davison W, Hyams DE, Irvine WJ. Vitamin 

B12 status in mentally disturbed elderly patients. Gerontol 

Clin. 1969;11(1):22-35. N<100 (B12 or Folate correlation) 

Calhau C, Martel F, SoaresdaSilva P, HipolitoReis C, 

Azevedo I. Regulation of [(3)H]MPP(+) transport by 

phosphorylation/dephosphorylation pathways in RBE4 

cells: role of ecto-alkaline phosphatase. NaunynSchmiedebergs Arch Pharmacol. 2002;365(5):349-56. Nonberry chemical 

Calingasan NY, Baker H, Sheu KF, Gibson GE. Bloodbrain barrier abnormalities in vulnerable brain regions 

during thiamine deficiency. Exp Neurol. 1995;134(1):64-

72. B vitamin antagonist 

Calingasan NY, Park LC, Gandy SE, Gibson GE. 

Disturbances of the blood-brain barrier without expression 

of amyloid precursor protein- containing neuritic clusters or 

neuronal loss during late stages of thiamine deficiency in 

guinea pigs. Dev Neurosci. 1998. B vitamin antagonist 

Campbell WA, Iskandar MK, Reed ML, Xia W. 

Endoproteolysis of presenilin in vitro: inhibition by 

gamma-secretase inhibitors. Biochemistry. 

2002;41(10):3372-9. Not B vitamin study 

Cao G, Shukitt-Hale B, Bickford PC, Joseph JA, McEwen 

J, Prior RL. Hyperoxia-induced changes in antioxidant 

capacity and the effect of dietary antioxidants. J Appl 

Physiol. 1999 Jun. Non-berry chemical 

Carlson RO, Aschmies SH. Tyrosine kinase activity is 

essential for interleukin-1 beta--stimulated production of 

interleukin-6 in U373 human astrocytoma cells. J 

Neurochem. 1995;65(6):2491-9. Non-berry chemical 

Casadesus G, ShukittHale B, Joseph JA. Qualitative versus 

quantitative caloric intake: are they equivalent paths to 

successful aging? Neurobiol Aging. 2002;23(5):747-69. 

Review 

Chan DK, Woo J, Ho SC, Pang CP, Law LK, Ng PW, 

Hung WT, Kwok T, Hui E, Orr K, Leung MF, Kay R. 

Genetic and environmental risk factors for Parkinson's 

disease in a Chinese population. J Neurol Neurosurg 

Psychiatry. 1998;65(5):781-4. Fruit, not berry 

Chan P, Cheng JT, Tsai JC, Lien GS, Chen FC, Kao PF, 

Liu JC, Chen YJ, Hsieh MH. Effect of catechin on the 

activity and gene expression of superoxide dismutase in 

cultured rat brain astrocytes. Neurosci Lett. 

2002;328(3):281-4. Non-berry chemical 

Chen CJ, Raung SL, Liao SL, Chen SY. Inhibition of 

inducible nitric oxide synthase expression by baicalein in 

endotoxin/cytokine-stimulated microglia. Biochem 

Pharmacol. 2004;67(5):957-65. Non-berry chemical 

Cho J, Lee HK. Wogonin inhibits ischemic brain injury in a 

rat model of permanent middle cerebral artery occlusion. 

Biol Pharm Bull. 2004;27(10):1561-4. Non-berry chemical 
D-3 

Choi E, Chee K, Choi M. The anti- and pro-oxidative 

effects of orally administered flavonoids in normal rats. 

Nutr Sci. 2004. Non-berry chemical 

Cole MG, Prchal JF. Low serum vitamin B12 in 

Alzheimer-type dementia. Age Ageing. 1984;13(2):101-5. 

N<100 (B12 or Folate correlation) 

Collins RC, Kirkpatrick JB, McDougal DB. Some regional 

pathologic and metabolic consequences in mouse brain of 

pyrithiamine-induced thiamine deficiency. J Neuropathol 

Exp Neurol. 1970;29(1):57-69. B vitamin antagonist 

Commenges D, Scotet V, Renaud S, JacqminGadda H, 

BarbergerGateau P, Dartigues JF. Intake of flavonoids and 

risk of dementia. Eur J Epidemiol. 2000;16(4):357-63. 

Non-berry chemical 

Conklin DR, Tan KH, Aschner M. Dimethyl sulfoxide, but 

not acidosis-induced metallothionein mRNA expression in 

neonatal rat primary astrocyte cultures is inhibited by the 

bioflavonoid, quercetin. Brain Res. 1998;794(2):304-8. 

Non-berry chemical 

Conte A, Pellegrini S, Tagliazucchi D. Effect of resveratrol 

and catechin on PC12 tyrosine kinase activities and their 

synergistic protection from beta-amyloid toxicity. Drugs 

Exp Clin Res. 2003;29(5-6):243-55. Non-berry chemical 

Conte A, Pellegrini S, Tagliazucchi D. Synergistic 

protection of PC12 cells from beta-amyloid toxicity by 

resveratrol and catechin. Brain Res Bull. 2003;62(1):29-38. 

Non-berry chemical 

Cowen MA, Green M, Bertollo DN, Abbott K. A treatment 

for tardive dyskinesia and some other extrapyramidal 

symptoms.[see comment]. J Clin Psychopharmacol. 

1997;17(3):190-3. Combination B vitamin and other 

treatments 

Cunha UG. An investigation of dementia among elderly 

outpatients. Acta Psychiatr Scand. 1990;82(3):261-3. No B 

vitamin results 

Cyrino LA, Cardoso RC, Hackl LP, Nicolau M. Effect of 

quercetin on plasma extravasation in rat CNS and dura 

mater by ACE and NEP inhibition. Phytother Res. 

2002;16(6):545-9. Non-berry chemical 

Dajas F, Rivera F, Blasina F, Arredondo F, Echeverry C, 

Lafon L, Morquio A, Heizen H. Cell culture protection and 

in vivo neuroprotective capacity of flavonoids. Neurotox 

Res. 2003;5(6):425-32. Non-berry chemical 

Dajas F, RiveraMegret F, Blasina F, Arredondo F, 

AbinCarriquiry JA, Costa G, Echeverry C, Lafon L, Heizen 

H, Ferreira M, Morquio A. Neuroprotection by flavonoids. 

Braz J Med Biol Res. 2003;36(12):1613-20. Review 

Davies J, Watkins JC. Facilitatory and direct excitatory 

effects of folate and folinate on single neurones of cat 

cerebral cortex. Biochem Pharmacol. 1973;22(13):1667-8. 

No outcome of interest 

Davis CW. Assessment of selective inhibition of rat 

cerebral cortical calcium-independent and calciumdependent phosphodiesterases in crude extracts using 

deoxycyclic AMP and potassium ions. Biochim Biophys 

Acta. 1984;797(3):354-62. Non-berry chemical 

de Luis DA, Fernandez N, Arranz M, Aller R, Izaola O. 

Total homocysteine and cognitive deterioration in people 

with type 2 diabetes. Diabetes Res Clin Pract. 

2002;55(3):185-90. N<100 (B12 or Folate correlation) 

de Rijk MC, Breteler MM, den Breeijen JH, Launer LJ, 

Grobbee DE, van der Meche FG, Hofman A. Dietary 

antioxidants and Parkinson disease. The Rotterdam Study. 

Arch Neurol. 1997;54(6):762-5. Non-berry chemical 

De Ruvo C, Amodio R, Algeri S, Martelli N, Intilangelo A, 

D'Ancona GM, Esposito E. Nutritional antioxidants as 

antidegenerative agents. Int J Dev Neurosci. 2000;18(4-

5):359-66. Non-berry chemical 

Dekermendjian K, Kahnberg P, Witt MR, Sterner O, 

Nielsen M, Liljefors T. Structure-activity relationships and 

molecular modeling analysis of flavonoids binding to the 

benzodiazepine site of the rat brain GABA(A) receptor 

complex. J Med Chem. 1999;42(21):4343-50. Non-berry 

chemical 

Diboune M, Ferard G, Ingenbleek Y, Bourguignat A, 

Spielmann D, SchepplerRoupert C, Tulasne PA, Calon B, 

Hasselmann M, Sauder P, Glasser N, Metais P. Soybean 

oil, blackcurrant seed oil, medium-chain triglycerides, and 

plasma phospholipid fatty acids of stressed patients. 

Nutrition. 1993. No outcomes of interest 

Dines KC, Cotter MA, Cameron NE. Effectiveness of 

natural oils as sources of gamma-linolenic acid to correct 

peripheral nerve conduction velocity abnormalities in 

diabetic rats: modulation by thromboxane A2 inhibition. 

Prostaglandins Leukot Essent Fatty Acids. 1996;55(3):159-

65. Non-berry 

Dufouil C, Alperovitch A, Ducros V, Tzourio C. 

Homocysteine, white matter hyperintensities, and cognition 

in healthy elderly people. Ann Neurol. 2003;53(2):214-21. 

No B vitamin results 

Durga J. Folate and age-related disease. Folate and agerelated disease. 2005. Thesis 

Duvoisin RC, Yahr MD, Cote LD. Pyridoxine reversal of 

L-dopa effects in Parkinsonism. Trans Am Neurol Assoc. 

1969;94:81-4. Pyridoxine and L-Dopa effect 
D-4 

Eastley R, Wilcock GK, Bucks RS. Vitamin B12 

deficiency in dementia and cognitive impairment: the 

effects of treatment on neuropsychological function. Int J 

Geriatr Psychiatry. 2000;15(3):226-33. Retrospective 

intervention 

Ebly EM, Schaefer JP, Campbell NR, Hogan DB. Folate 

status, vascular disease and cognition in elderly Canadians. 

Age Ageing. 1998;27(4):485-91. Ineligible population 

(and/or no sub-analysis of age-related neurocognitive 

disease) 

Elliott P, HooverPlow J. Excess dietary vitamin B6 alters 

water maze performance in two strains of mice. Nutr Res. 

1989. Model of genetic B6 disorder 

End DW, Look RA, Shaffer NL, Balles EA, Persico FJ. 

Non-selective inhibition of mammalian protein kinases by 

flavinoids in vitro. Res Commun Chem Pathol Pharmacol. 

1987;56(1):75-86. Non-berry chemical 

Engelhart MJ, Geerlings MI, Ruitenberg A, van Swieten 

JC, Hofman A, Witteman JC, Breteler MM. Dietary intake 

of antioxidants and risk of Alzheimer disease. JAMA. 

2002;287(24):3223-9. Non-berry chemical 

EssamaTjani JC, Guilland JC, Potier dC, Fuchs F, Richard 

D. Folate status worsens in recently institutionalized elderly 

people without evidence of functional deterioration. J Am 

Coll Nutr. 2000. No B vitamin results 

Fahn S. 'On-off' phenomenon with levodopa therapy in 

Parkinsonism. Clinical and pharmacologic correlations and 

the effect of intramuscular pyridoxine. Neurology. 

1974;24(5):431-41. Pyridoxine and L-Dopa effect 

Farina E, Pomati S, Mariani C. Observations on dementias 

with possibly reversible symptoms. Aging Clin Exp Res. 

1999;11(5):323-8. No B vitamin results 

Feng R, He W, Ochi H. A new murine oxidative stress 

model associated with senescence. Mech Ageing Dev. 

2001;122(6):547-59. Non-berry chemical 

Ferriola PC, Cody V, Middleton E Jr. Protein kinase C 

inhibition by plant flavonoids. Kinetic mechanisms and 

structure-activity relationships. Biochem Pharmacol. 

1989;38(10):1617-24. Non-berry chemical 

Fischer P, Gotz ME, Ellinger B, Streifler M, Riederer P, 

Danielczyk W. Platelet monoamine oxidase B activity and 

vitamin B12 in dementia. Biol Psychiatry. 

1994;35(10):772-4. N<100 (B12 or Folate correlation) 

Flicker L, Martins RN, Thomas J, Acres J, Taddei K, 

Norman P, Jamrozik K, Almeida OP. Homocysteine, 

Alzheimer genes and proteins, and measures of cognition 

and depression in older men. J Alzheimers Dis. 

2004;6(3):329-36. No B vitamin results 

Forti P, Maioli F, Nesi B, Vettori C, Flisi E, Dalmonte E, 

Zanardi V, Lodi L, Macini P, Caldarera M, Ravaglia G. 

Conselice study: a population based survey of brain aging 

in a municipality of the Emilia Romagna region: (A.U.S.L. 

Ravenna), neuropsychological tests and nutritional status. 

Arch Gerontol Geriatr. 2005. N<100 (B12 or Folate 

correlation) 

Franchi F, Baio G, Bolognesi AG, Bonassi R, Emiliani S, 

Gobbi G, Luchetti L, Zurla L. Deficient folate nutritional 

status and cognitive performances: results from a 

retrospective study in male elderly inpatients in a geriatric 

department. Arch Gerontol Geriatr. 2005. Ineligible 

population (and/or no sub-analysis of age-related 

neurocognitive disease) 

Freeman GB, Nielsen PE, Gibson GE. Effect of age on 

behavioral and enzymatic changes during thiamin 

deficiency. Neurobiol Aging. 1987;8(5):429-34. B vitamin 

antagonist 

Freemon FR. Evaluation of patients with progressive 

intellectual deterioration. Arch Neurol. 1976;33(9):658-9. 

Ineligible population (and/or no sub-analysis of age-related 

neurocognitive disease) 

Gaitonde MK. Decreased turnover of N-acetylaspartate in 

the brain of thiamine-deficient rats. J Neurochem. 

1979;32(5):1603-4. No outcome of interest 

Gale JM, Brosemer RW. Effect of pyrithiamine treatment 

on potassium ion fluxes in rat cortical slices. Biochim 

Biophys Acta. 1984;773(1):125-31. B vitamin antagonist 

Galli RL, ShukittHale B, Youdim KA, Joseph JA. Fruit 

polyphenolics and brain aging: nutritional interventions 

targeting age-related neuronal and behavioral deficits. Ann 

N Y Acad Sci. 2002;959:128-32. Review 

Gallucci M, Zanardo A, De Valentin L, Vianello A. 

Homocysteine in Alzheimer disease and vascular dementia. 

Arch Gerontol Geriatr Suppl. 2005;(9):195-200. No B 

vitamin results 

Gelinas S, Martinoli MG. Neuroprotective effect of 

estradiol and phytoestrogens on MPP+-induced 

cytotoxicity in neuronal PC12 cells. J Neurosci Res. 

2002;70(1):90-6. Non-berry chemical 

Ghandour H, Chen Z, Selhub J, Rozen R. Mice deficient in 

methylenetetrahydrofolate reductase exhibit tissue-specific 

distribution of folates. J Nutr. 2004;134(11):2975-8. No 

outcome of interest 

Gibson G, Nielsen P, Mykytyn V, Carlson K, Blass J. 

Regionally selective alterations in enzymatic activities and 

metabolic fluxes during thiamin deficiency. Neurochem 

Res. 1989;14(1):17-24. No outcome of interest 

Gibson GE, Calingasan NY, Baker H, Gandy S, Sheu KF. 

Importance of vascular changes in selective 

neurodegeneration with thiamine deficiency. Ann N Y 

Acad Sci. 1997;826:516-9. Review 
D-5 

Gibson GE, KsiezakReding H, Sheu KF, Mykytyn V, Blass 

JP. Correlation of enzymatic, metabolic, and behavioral 

deficits in thiamin deficiency and its reversal. Neurochem 

Res. 1984;9(6):803-14. B vitamin antagonist 

Giem P, Beeson WL, Fraser GE. The incidence of dementia 

and intake of animal products: preliminary findings from 

the Adventist Health Study. Neuroepidemiology. 

1993;12(1):28-36. Non-berry 

Glaso M, Nordbo G, Diep L, Bohmer T. Reduced 

concentrations of several vitamins in normal weight 

patients with late-onset dementia of the Alzheimer type 

without vascular disease. J Nutr Health Aging. 

2005;8(5):407-13. N<100 (B12 or Folate correlation) 

Gomes-Trolin C, Gottfries CG, Regland B, Oreland L. 

Influence of vitamin B12 on brain methionine 

adenosyltransferase activity in senile dementia of the 

Alzheimer's type. J Neural Transm. 1996;103(7):861-72. 

No outcome of interest 

Gomes-Trolin C, Regland B, Oreland L. Decreased 

methionine adenosyltransferase activity in erythrocytes of 

patients with dementia disorders. Eur 

Neuropsychopharmaco. 1995;5(2):107-14. No outcome of 

interest 

Grabow JD, Linkswiler H. Electroencephalographic and 

nerve-conduction studies in experimental vitamin B 6 

deficiency in adults. Am J Clin Nutr. 1969;22(11):1429-34. 

Ineligible population (and/or no sub-analysis of age-related 

neurocognitive disease) 

Greer A, McBride DH, Shenkin A. Comparison of the 

nutritional state of new and long-term patients in a 

psychogeriatric unit. Br J Psychiatry. 1986;149:738-41. No 

outcome of interest 

Gu ZL, Xiao D, Jin LQ, Fan PS, Qian ZN. Effects of 

quercetin on Na(+)-K(+)-exchanging ATPase and Ca(2+) 

Mg(2+)-ATPase in rats. Chung Kuo Yao Li Hsueh Pao. 

1994;15(5):414-6. Non-berry chemical 

Guilarte TR. Reduced NMDA receptor-ion channel 

function in the vitamin B-6 restricted neonatal rat brain. 

Neurosci Lett. 1991;121(1-2):207-10. No outcome of 

interest 

Gupta R, Singh M, Sharma A. Neuroprotective effect of 

antioxidants on ischaemia and reperfusion-induced cerebral 

injury. Pharmacol Res. 2003;48(2):209-15. Non-berry 

chemical 

Ha HJ, Kwon YS, Park SM, Shin T, Park JH, Kim HC, 

Kwon MS, Wie MB. Quercetin attenuates oxygen-glucose 

deprivation- and excitotoxin-induced neurotoxicity in 

primary cortical cell cultures. Biol Pharm Bull 26(4):544-6. 

2003 Non-berry chemical 

Hakim AM. Effect of thiamine deficiency and its reversal 

on cerebral blood flow in the rat. Observations on the 

phenomena of hyperperfusion, 'no reflow,' and delayed 

hypoperfusion. J Cereb Blood Flow Metab. 1986;6(1):79-

85. No outcome of interest 

Haller J, Weggemans RM, Ferry M, Guigoz Y. Mental 

health: minimental state examination and geriatric 

depression score of elderly Europeans in the SENECA 

study of 1993. Eur J Clin Nutr. 1996. All normal cognition 

(correlation study) 

Halliwell B. Antioxidant activity and other biological 

effects of flavonoids. International Congress and 

Symposium Series - Royal Society of Medicine. 2000. 

Review 

Hancock MR, Hullin RP, Aylard PR, King JR, Morgan DB. 

Nutritional state of elderly women on admission to mental 

hospital. Br J Psychiatry. 1985;147:404-7. Combination B 

vitamin and other treatments 

Hannum SM. Potential impact of strawberries on human 

health: a review of the science. Crit Rev Food Sci Nutr. 

2004;44(1):1-17. Review 

Harata N, Iwasaki Y. Evidence for early blood-brain barrier 

breakdown in experimental thiamine deficiency in the 

mouse. Metab Brain Dis. 1995;10(2):159-74. B vitamin 

antagonist 

Hassing L, Wahlin A, Winblad B, Backman L. Further 

evidence on the effects of vitamin B12 and folate levels on 

episodic memory functioning: a population-based study of 

healthy very old adults. Biol Psychiatry. 1999;45(11):1472-

80. N<100 (B12 or Folate correlation) 

Hatta S, Watanabe M, Ikeda H, Kamada H, Saito T, 

Ohshika H. Impairment of adenylyl cyclase signal 

transduction in mecobalamin-deficient rats. Eur J 

Pharmacol. 1995;291(3):351-8.. No outcome of interest 

Healton EB, Savage DG, Brust JC, Garrett TJ, Lindenbaum 

J. Neurologic aspects of cobalamin deficiency. Medicine. 

1991;70(4):229-45. Ineligible population (and/or no subanalysis of age-related neurocognitive disease) 

Hellenbrand W, Seidler A, Boeing H, Robra BP, Vieregge 

P, Nischan P, Joerg J, Oertel WH, Schneider E, Ulm G. 

Diet and Parkinson's disease. I: A possible role for the past 

intake of specific foods and food groups. Results from a 

self-administered food-frequency questionnaire in a casecontrol study. Neurology. 1996;47(3):636-43. Fruit, not 

berry 

Hendriks JJ, de Vries HE, van der Pol SM, van den Berg 

TK, van Tol EA, Dijkstra CD. Flavonoids inhibit myelin 

phagocytosis by macrophages, a structure-activity 

relationship study. Biochem Pharmacol. 2003;65(5):877-

85. Non-berry chemical 
D-6 

Heseker H, Kubler W, Pudel V, Westenhofer J. Interaction 

of vitamins with mental performance. Bibl Nutr Dieta. 

1995;(52):43-55. Combination B vitamin and other 

treatments 

Ho PI, Ashline D, Dhitavat S, Ortiz D, Collins SC, Shea 

TB, Rogers E. Folate deprivation induces 

neurodegeneration: roles of oxidative stress and increased 

homocysteine. Neurobiol Dis. 2003;14(1):32-42. No 

outcome of interest 

Hollman PC, Katan MB. Health effects and bioavailability 

of dietary flavonols. Free Radic Res. 1999;31 Suppl:S75-

80. Review 

Homewood J, Bond NW, McGregor JC. The effects of 

chronic alcohol consumption or thiamin deficiency on 

radial-arm maze performance in the rat. Alcohol. 

1991;8(4):265-72. Not B vitamin study 

Homewood. The effects of chronic alcohol consumption or 

thiamin deficiency on radial-arm maze performance in the 

rat. Alcohol. 1991;8(4):265-72. B vitamin antagonist 

Houzen H, Kanno M. Thiamine and its derivatives inhibit 

delayed rectifier potassium channels of rat cultured cortical 

neurons. Neuropharmacology. 1998;37(3):313-22. No 

outcome of interest 

Hsu TH, Bianchine JR, Preziosi TJ, Messiha FS. Effect of 

pyridoxine on levodopa metabolism in normal and 

parkinsonian subjects. Proc Soc Exp Biol Med. 

1973;143(2):578-81. Pyridoxine and L-Dopa effect 

Huang MT, Lysz T, Ferraro T, Abidi TF, Laskin JD, 

Conney AH. Inhibitory effects of curcumin on in vitro 

lipoxygenase and cyclooxygenase activities in mouse 

epidermis. Cancer Res. 1991;51(3):813-9. Non-berry 

chemical 

Hung SC, Hung SH, Tarng DC, Yang WC, Chen TW, 

Huang TP. Thiamine deficiency and unexplained 

encephalopathy in hemodialysis and peritoneal dialysis 

patients. Am J Kidney Dis. 2001;38(5):941-7. Ineligible 

population (and/or no sub-analysis of age-related 

neurocognitive disease) 

Ikeda T, Furukawa Y, Mashimoto S, Takahashi K, Yamada 

M. Vitamin B12 levels in serum and cerebrospinal fluid of 

people with Alzheimer's disease. Acta Psychiatr Scand. 

1990;82(4):327-9. N<100 (B12 or Folate correlation) 

Inanami O, Watanabe Y, Syuto B, Nakano M, Tsuji M, 

Kuwabara M. Oral administration of (-)catechin protects 

against ischemia-reperfusion-induced neuronal death in the 

gerbil. Free Radic Res. 1998;29(4):359-65. Non-berry 

chemical 

Irle E, Markowitsch HJ. Thiamine deficiency in the cat 

leads to severe learning deficits and to widespread 

neuroanatomical damage. Exp Brain Res. 1982;48(2):199-

208. B vitamin antagonist 

Ishige K, Schubert D, Sagara Y. Flavonoids protect 

neuronal cells from oxidative stress by three distinct 

mechanisms. Free Radic Biol Med. 2001;30(4):433-46. 

Non-berry chemical 

Je HD, Shin CY, Park SY, Yim SH, Kum C, Huh IH, Kim 

JH, Sohn UD. Combination of vitamin C and rutin on 

neuropathy and lung damage of diabetes mellitus rats. Arch 

Pharm Res. 2002;25(2):184-90. Non-berry chemical 

Jelicic M, Jonker C, Deeg DJ. Effect of low levels of serum 

vitamin B12 and folic acid on cognitive performance in old 

age: a population-based study. Dev Neuropsychol. 2002. 

All normal cognition (correlation study) 

Ji XD, Melman N, Jacobson KA. Interactions of flavonoids 

and other phytochemicals with adenosine receptors. J Med 

Chem. 1996;39(3):781-8. Non-berry chemical 

Jones JM. Nutrition. Cereal Foods World. 2003. Review 

Joseph JA, Denisova N, Fisher D, Bickford P, Prior R, Cao 

G. Age-related neurodegeneration and oxidative stress: 

putative nutritional intervention. Neurol Clin. 

1998;16(3):747-55. Review 

Joseph JA, Denisova NA, Bielinski D, Fisher DR, 

ShukittHale B. Oxidative stress protection and vulnerability 

in aging: putative nutritional implications for intervention. 

Mech Ageing Dev. 2000;116(2-3):141-53. Review 

Joseph JA, Denisova NA, Bielinski D, Fisher DR, 

ShukittHale B. Oxidative stress protection and vulnerability 

in aging: putative nutritional implications for intervention. 

Mech Ageing Dev. 2000;116(2-3):141-53. Review 

Joseph JA, ShukittHale B, Casadesus G. Reversing the 

deleterious effects of aging on neuronal communication 

and behavior: beneficial properties of fruit polyphenolic 

compounds. Am J Clin Nutr. 2005;81(1 Suppl):313S-316S. 

Review 

Kang S, Lee J, Choi Y, Kim G, Han B. Neuroprotective 

effects of flavones on hydrogen peroxide-induced apoptosis 

in SH-SY5Y neuroblostoma cells. Bioorganic & Medicinal 

Chemistry Letters. 2004. Non-berry chemical 

Kanski J, Aksenova M, Stoyanova A, Butterfield DA. 

Ferulic acid antioxidant protection against hydroxyl and 

peroxyl radical oxidation in synaptosomal and neuronal cell 

culture systems in vitro: structure-activity studies. J Nutr 

Biochem. 2002. Non-berry chemical 

Karnaze DS, Carmel R. Low serum cobalamin levels in 

primary degenerative dementia. Do some patients harbor 

atypical cobalamin deficiency states? Arch Intern Med. 

1987;147(3):429-31. N<100 (B12 or Folate correlation) 

Karton Y, Jiang JL, Ji XD, Melman N, Olah ME, Stiles 

GL, Jacobson KA. Synthesis and biological activities of 

flavonoid derivatives as A3 adenosine receptor antagonists. 

J Med Chem. 1996;39(12):2293-301. Non-berry chemical 
D-7 

Ke ZJ, DeGiorgio LA, Volpe BT, Gibson GE. Reversal of 

thiamine deficiency-induced neurodegeneration. J 

Neuropathol Exp Neurol. 2003;62(2):195-207. B vitamin 

antagonist 

Kim HS, Cho JY, Kim DH, Yan JJ, Lee HK, Suh HW, 

Song DK. Inhibitory effects of long-term administration of 

ferulic acid on microglial activation induced by 

intracerebroventricular injection of beta-amyloid peptide 

(1-42) in mice. Biol Pharm Bull. 2004;27(1):120-1. Nonberry chemical 

Klawans HL, Ringel SP, Shenker DM. Failure of vitamin 

B6 to reverse the L-dopa effect in patients on a dopa 

decarboxylase inhibitor. J Neurol Neurosurg Psychiatry. 

1971;34(6):682-6. Retrospective intervention 

Knekt P, Kumpulainen J, Jarvinen R, Rissanen H, 

Heliovaara M, Reunanen A, Hakulinen T, Aromaa A. 

Flavonoid intake and risk of chronic diseases. Am J Clin 

Nutr. 2002;76(3):560-8. No outcomes of interest 

Ko HH, Yu SM, Ko FN, Teng CM, Lin CN. Bioactive 

constituents of Morus australis and Broussonetia 

papyrifera. J Nat Prod. 1997;60(10):1008-11. Non-berry 

Koehler KM, PareoTubbeh SL, Romero LJ, Baumgartner 

RN, Garry PJ. Folate nutrition and older adults: challenges 

and opportunities. J Am Diet Assoc. 1997;97(2):167-73. 

No outcome of interest 

Koh SH, Kim SH, Kwon H, Park Y, Kim KS, Song CW, 

Kim J, Kim MH, Yu HJ, Henkel JS, Jung HK. 

Epigallocatechin gallate protects nerve growth factor 

differentiated PC12 cells from oxidative-radical-stressinduced apoptosis through its effect on phosphoinositide 3-

kinase/Akt and glycogen synthase kinase-3. Brain Res Mol 

Brain Res. 2003;118(1-2):72-81. Non-berry chemical 

Kong LD, Cheng CH, Tan RX. Inhibition of MAO A and B 

by some plant-derived alkaloids, phenols and 

anthraquinones. J Ethnopharmacol. 2004;91(2-3):351-5. 

Non-berry chemical 

Laurin D, Masaki KH, Foley DJ, White LR, Launer LJ. 

Midlife dietary intake of antioxidants and risk of late-life 

incident dementia: the Honolulu-Asia Aging Study. Am J 

Epidemiol. 2004;159(10):959-67. Non-berry chemical 

Leblhuber F, Walli J, ArtnerDworzak E, Vrecko K, Widner 

B, Reibnegger G, Fuchs D. Hyperhomocysteinemia in 

dementia. J Neural Transm. 2000;107(12):1469-74. N<100 

(B12 or Folate correlation) 

Lee L, Kang SA, Lee HO, Lee BH, Park JS, Kim JH, Jung 

IK, Park YJ, Lee JE. Relationships between dietary intake 

and cognitive function level in Korean elderly people. 

Public Health. 2001;115(2):133-8. Fruit, not berry 

Lee M, Lee K, Kim H, Hong S, Ro J. Inhibitory effects of 

coptisine on monoamine oxidase activity. Nat Prod Sci. 

2000. Unable to retrieve 

Leon AS, Spiegel HE, Thomas G, Abrams WB. Pyridoxine 

antagonism of levodopa in parkinsonism. JAMA. 

1971;218(13):1924-7. Pyridoxine and L-Dopa effect 

Levinson BM. The blueberry syndrome. Psychol Rep. 

1980;46(1):47-52. No outcomes of interest 

Levitt AJ, Karlinsky H. Folate, vitamin B12 and cognitive 

impairment in patients with Alzheimer's disease. Acta 

Psychiatr Scand. 1992;86(4):301-5. N<100 (B12 or Folate 

correlation) 

Lin Y, Desbois A, Jiang S, Hou ST. Group B vitamins 

protect murine cerebellar granule cells from 

glutamate/NMDA toxicity. Neuroreport. 

2004;15(14):2241-4. No outcome of interest 

Lin YM, Raffen R, Zhou Y, Cassidy CS, Flavin MT, 

Stevens FJ. Amyloid fibril formation in microwell plates 

for screening of inhibitors. Amyloid. 2001;8(3):182-93. 

Non-berry 

Lindboe CF, Loberg EM. Wernicke's encephalopathy in 

non-alcoholics. An autopsy study. J Neurol Sci. 

1989;90(2):125-9. No outcome of interest 

Liu RH. Health benefits of fruit and vegetables are from 

additive and synergistic combinations of phytochemicals. 

Am J Clin Nutr. 2003;78(3 Suppl):517S-520S. Review 

Lopez OL, Becker JT, Klunk W, Saxton J, Hamilton RL, 

Kaufer DI, Sweet RA, Cidis MC, Wisniewski S, Kamboh 

MI, DeKosky ST. Research evaluation and diagnosis of 

possible Alzheimer's disease over the last two decades: II. 

Neurology. 2000;55(12):1863-9. No B vitamin results 

Lopponen M, Raiha I, Isoaho R, Vahlberg T, Kivela SL. 

Diagnosing cognitive impairment and dementia in primary 

health care -- a more active approach is needed.[see 

comment]. Age Ageing. 2003;32(6):606-12. No outcome of 

interest 

Lorenz P, Roychowdhury S, Engelmann M, Wolf G, Horn 

TF. Oxyresveratrol and resveratrol are potent antioxidants 

and free radical scavengers: effect on nitrosative and 

oxidative stress derived from microglial cells. Nitric Oxide. 

2003;9(2):64-76. Non-berry chemical 

Losi G, Puia G, Garzon G, de Vuono MC, Baraldi M. 

Apigenin modulates GABAergic and glutamatergic 

transmission in cultured cortical neurons. Eur J Pharmacol. 

2004;502(1-2):41-6. Non-berry chemical 

Maguire TM, Breen KC. A decrease in neural 

sialyltransferase activity in Alzheimer's disease. Dementia. 

1995;6(4):185-90. No B vitamin results 

Mair RG, Anderson CD, Langlais PJ, McEntee WJ. 

Behavioral impairments, brain lesions and monoaminergic 

activity in the rat following recovery from a bout of 

thiamine deficiency. Behav Brain Res. 1988;27(3):223-39. 

B vitamin antagonist 
D-8 

Mair RG, Anderson CD, Langlais PJ, McEntee WJ. 

Thiamine deficiency depletes cortical norepinephrine and 

impairs learning processes in the rat. Brain Res. 

1985;360(1-2):273-84. B vitamin antagonist 

Manz HJ, Robertson DM. Vascular permeability to 

horseradish peroxidase in brainstem lesions of thiaminedeficient rats. Am J Pathol. 1972;66(3):565-76. Immature 

rats 

Marengoni A, Cossi S, De Martinis M, Calabrese PA, Orini 

S, Grassi V. Homocysteine and disability in hospitalized 

geriatric patients. Metabolism. 2004;53(8):1016-20. 

Ineligible population (and/or no sub-analysis of age-related 

neurocognitive disease) 

Mars H. Levodopa, carbidopa, and pyridoxine in Parkinson 

disease. Metabolic interactions. Arch Neurol. 

1974;30(6):444-7. Pyridoxine and L-Dopa effect 

Mars H. Metabolic interactions of pyridoxine, levodopa, 

and carbidopa in Parkinson's disease. Trans Am Neurol 

Assoc. 1973;98:241-5. Pyridoxine and L-Dopa effect 

Martin A, Cherubini A, AndresLacueva C, Paniagua M, 

Joseph J. Effects of fruits and vegetables on levels of 

vitamins E and C in the brain and their association with 

cognitive performance. J Nutr Health Aging. 

2002;6(6):392-404. Review 

Mastrogiacomo F, Bergeron C, Kish SJ. Brain alphaketoglutarate dehydrogenase complex activity in 

Alzheimer's disease. J Neurochem. 1993;61(6):2007-14. 

Not B vitamin study 

Mazzio EA, Harris N, Soliman KF. Food constituents 

attenuate monoamine oxidase activity and peroxide levels 

in C6 astrocyte cells. Planta Med. 1998;64(7):603-6. Nonberry chemical 

McCaddon A, Davies G, Hudson P, Tandy S, Cattell H. 

Total serum homocysteine in senile dementia of Alzheimer 

type. Int J Geriatr Psychiatry. 1998;13(4):235-9. N<100 

(B12 or Folate correlation) 

McCaddon A, Hudson P, Abrahamsson L, Olofsson H, 

Regland B. Analogues, ageing and aberrant assimilation of 

vitamin B12 in Alzheimer's disease. Dement Geriatr Cogn 

Disord. 2001;12(2):133-7. N<100 (B12 or Folate 

correlation) 

McCaddon A, Kelly CL. Familial Alzheimer's disease and 

vitamin B12 deficiency. Age Ageing. 1994;23(4):334-7. 

N<100 (B12 or Folate correlation) 

McGeer PL, Zeldowicz L, McGeer EG. A clinical trial of 

folic acid in Parkinson's disease. Can Med Assoc J. 

1972;106(2):145-6 passim. No outcome of interest 

McKenna MC, Tildon JT, Stevenson JH, Hopkins IB, 

Huang X, Couto R. Lactate transport by cortical 

synaptosomes from adult rat brain: characterization of 

kinetics and inhibitor specificity. Dev Neurosci. 1920. Nonberry chemical 

Meins W, MullerThomsen T, MeierBaumgartner HP. 

Subnormal serum vitamin B12 and behavioural and 

psychological symptoms in Alzheimer's disease. Int J 

Geriatr Psychiatry. 2000;15(5):415-8. N<100 (B12 or 

Folate correlation) 

Melzig MF, Escher F. Induction of neutral endopeptidase 

and angiotensin-converting enzyme activity of SK-N-SH 

cells in vitro by quercetin and resveratrol. Pharmazie. 

2002;57(8):556-8. Non-berry chemical 

Meydani M. Nutrition interventions in aging and ageassociated disease. Ann N Y Acad Sci. 2001;928:226-35. 

Review 

Mihalick SM, Ortiz D, Kumar R, Rogers E, Shea TB. 

Folate and vitamin E deficiency impair cognitive 

performance in mice subjected to oxidative stress: 

differential impact on normal mice and mice lacking 

apolipoprotein E. Neuromolecular Med. 2003;4(3):197-

202. Combination B vitamin and other treatments 

Miller JW, Green R, Ramos MI, Allen LH, Mungas DM, 

Jagust WJ, Haan MN. Homocysteine and cognitive 

function in the Sacramento Area Latino Study on Aging. 

Am J Clin Nutr. 2003;78(3):441-7. No B vitamin results 

Miller JW, Selhub J, Nadeau MR, Thomas CA, Feldman 

RG, Wolf PA. Effect of L-dopa on plasma homocysteine in 

PD patients: relationship to B-vitamin status. Neurology. 

2003;60(7):1125-9. No outcome of interest 

Miller JW. Folate, cognition, and depression in the era of 

folic acid fortification. J Food Sci. 2005. Review 

Milward EA, Grayson DA, Creasey H, Janu MR, Brooks 

WS, Broe GA. Evidence for association of anaemia with 

vascular dementia. Neuroreport. 1999;10(11):2377-81. No 

B vitamin results 

Molimard R, Marillaud A, Paille A, Le Devehat C, 

Lemoine A, Dougny M. Impairment of memorization by 

high doses of pyridoxine in man. Biomedicine. 

1980;32(2):88-92. Ineligible population (and/or no subanalysis of age-related neurocognitive disease) 

MolinaJimenez MF, SanchezReus MI, Benedi J. Effect of 

fraxetin and myricetin on rotenone-induced cytotoxicity in 

SH-SY5Y cells: comparison with N-acetylcysteine. Eur J 

Pharmacol. 2003;472(1-2):81-7. Non-berry chemical 

Moretti R, Torre P, Antonello RM, Cazzato G, Cattaruzza 

T, Scapicchio PL. Vitamin B12 and folate depletion: 

clinical evidence in a neurological population. Neurologist. 

2004;10(6):338-43. Review 
D-9 

Murphy MP, Uljon SN, Golde TE, Wang R. FAD-linked 

mutations in presenilin 1 alter the length of Abeta peptides 

derived from betaAPP transmembrane domain mutants. 

Biochim Biophys Acta. 2002;1586(2):199-209. Not B 

vitamin study 

Murphy P, Sharp A, Shin J, Gavrilyuk V, Dello RC, 

Weinberg G, Sharp FR, Lu A, Heneka MT, Feinstein DL. 

Suppressive effects of ansamycins on inducible nitric oxide 

synthase expression and the development of experimental 

autoimmune encephalomyelitis. J Neurosci Res. 

2002;67(4):461-70. Non-berry chemical 

Muthian G, Bright JJ. Quercetin, a flavonoid 

phytoestrogen, ameliorates experimental allergic 

encephalomyelitis by blocking IL-12 signaling through 

JAK-STAT pathway in T lymphocyte. J Clin Immunol. 

2004. Non-berry chemical 

Naidu PS, Kulkarni SK. Quercetin, a bioflavonoid, reverses 

haloperidol-induced catalepsy. Methods Find Exp Clin 

Pharmacol. 2004;26(5):323-6. Non-berry chemical 

Naidu PS, Singh A, Kulkarni SK. Quercetin, a 

bioflavonoid, attenuates haloperidol-induced orofacial 

dyskinesia. Neuropharmacology. 2003;44(8):1100-6. Nonberry chemical 

Naidu PS, Singh A, Kulkarni SK. Reversal of haloperidolinduced orofacial dyskinesia by quercetin, a bioflavonoid. 

Psychopharmacology. 2003;167(4):418-23. Non-berry 

chemical 

Naidu PS, Singh A, Kulkarni SK. Reversal of reserpineinduced orofacial dyskinesia and cognitive dysfunction by 

quercetin. Pharmacology. 2004;70(2):59-67. Non-berry 

chemical 

Nakata N, Kato H, Kogure K. Inhibition of ischaemic 

tolerance in the gerbil hippocampus by quercetin and antiheat shock protein-70 antibody. Neuroreport. 

1993;4(6):695-8. Non-berry chemical 

Nardini M, Leonardi F, Scaccini C, Virgili F. Modulation 

of ceramide-induced NF-kappaB binding activity and 

apoptotic response by caffeic acid in U937 cells: 

comparison with other antioxidants. Free Radic Biol Med. 

2001;30(7):722-33. Non-berry chemical 

Nes M, Sem SW, Rousseau B, Bjorneboe GE, Engedal K, 

Trygg K, Pedersen JI. Dietary intakes and nutritional status 

of old people with dementia living at home in Oslo. Eur J 

Clin Nutr. 1988;42(7):581-93. N<100 (B12 or Folate 

correlation) 

Nijst TQ, Wevers RA, Schoonderwaldt HC, Hommes OR, 

de Haan AF. Vitamin B12 and folate concentrations in 

serum and cerebrospinal fluid of neurological patients with 

special reference to multiple sclerosis and dementia. J 

Neurol Neurosurg Psychiatry. 1990;53(11):951-4. N<30 

(dementia) 

Nilsson K, Gustafson L, Hultberg B. The plasma 

homocysteine concentration is better than that of serum 

methylmalonic acid as a marker for sociopsychological 

performance in a psychogeriatric population. Clinical 

Chemistry. 2000;46(5):691-6. Ineligible population (and/or 

no sub-analysis of age-related neurocognitive disease) 

Nilsson K, Warkentin S, Hultberg B, Faldt R, Gustafson L. 

Treatment of cobalamin deficiency in dementia, evaluated 

clinically and with cerebral blood flow measurements. 

Aging Clin Exp Res. 2000;12(3):199-207. Ineligible 

population (and/or no sub-analysis of age-related 

neurocognitive disease) 

Ono K, Hasegawa K, Naiki H, Yamada M. Antiamyloidogenic activity of tannic acid and its activity to 

destabilize Alzheimer's beta-amyloid fibrils in vitro. 

Biochim Biophys Acta. 2004;1690(3):193-202. Non-berry 

chemical 

Ortiz OE, Sjodin RA, Boyne A. ATP-dependent calcium 

accumulation by non-mitochondrial organelles of axoplasm 

isolated from Myxicola giant axons. Biochim Biophys 

Acta. 1985;814(1):13-22. Non-berry 

O'Suilleabhain PE, Sung V, Hernandez C, Lacritz L, 

Dewey RB, Bottiglieri T, DiazArrastia R. Elevated plasma 

homocysteine level in patients with Parkinson disease: 

motor, affective, and cognitive associations. Arch Neurol. 

2004;61(6):865-8. No B vitamin results 

Pai TG, Suiko M, Sakakibara Y, Liu M. Sulfation of 

flavonoids and other phenolic dietary compounds by the 

human cytosolic sulfotransferases. Biochem Biophys Res 

Commun. 2001. Non-berry chemical 

Pak KJ, Chan SL, Mattson MP. Homocysteine and folate 

deficiency sensitize oligodendrocytes to the cell deathpromoting effects of a presenilin-1 mutation and amyloid 

beta-peptide. Neuromolecular Med. 2005;3(2):119-28. No 

outcome of interest 

Panneerselvam K, Balasubramanian AS. Lysosomal 

enzyme binding receptor protein from monkey brain and its 

phosphorylation. Indian J Biochem Biophys. 1991;28(5-

6):395-400. Non-berry chemical 

Parnetti L, Mecocci P, Reboldi GP, Santucci C, Brunetti M, 

Gaiti A, Cadini D, Senin U. Platelet MAO-B activity and 

vitamin B12 in old age dementias. Mol Chem Neuropathol. 

1992;16(1-2):23-32. N<100 (B12 or Folate correlation) 

Patil CS, Singh VP, Satyanarayan PS, Jain NK, Singh A, 

Kulkarni SK. Protective effect of flavonoids against agingand lipopolysaccharide-induced cognitive impairment in 

mice. Pharmacology. 2003;69(2):59-67. Non-berry 

chemical 
D-10 

Pepersack T, Garbusinski J, Robberecht J, Beyer I, Willems 

D, Fuss M. Clinical relevance of thiamine status amongst 

hospitalized elderly patients. Gerontology. 1999;45(2):96-

101. Ineligible population (and/or no sub-analysis of agerelated neurocognitive disease) 

Petri S, Petri C. Effect of vitamin B6 upon gastroprival 

central nervous system degenerations. 3. Acta Med Scand. 

1970;187(1-2):129-31. No outcome of interest 

Pfeiffer R, Ebadi M. On the mechanism of the nullification 

of CNS effects of L-DOPA by pyridoxine in Parkinsonian 

patients. J Neurochem. 1972. No outcome of interest 

Phillis JW, O'Regan MH. Evidence for swelling-induced 

adenosine and adenine nucleotide release in rat cerebral 

cortex exposed to monocarboxylate-containing or 

hypotonic artificial cerebrospinal fluids. Neurochem Int. 

2002;(7):629-35. Non-berry chemical 

Piantelli M, Rinelli A, Macri E, Maggiano N, Larocca LM, 

Scerrati M, Roselli R, Iacoangeli M, Scambia G, Capelli A. 

Type II estrogen binding sites and antiproliferative activity 

of quercetin in human meningiomas. Cancer. 

1993;71(1):193-8. Non-berry chemical 

Picq M, Cheav SL, Prigent AF. Effect of two flavonoid 

compounds on central nervous system. Analgesic activity. 

Life Sci. 1991;49(26):1979-88. Non-berry chemical 

Picq M, Dubois M, MunariSilem Y, Prigent AF, Pacheco 

H. Flavonoid modulation of protein kinase C activation. 

Life Sci 44(21):1563-71. 1989. Non-berry chemical 

Pirttila T, Salo J, Laippala P, Frey H. Effect of advanced 

brain atrophy and vitamin deficiency on cognitive functions 

in non-demented subjects. Acta Neurol Scand. 

1993;87(2):161-6. Ineligible population (and/or no subanalysis of age-related neurocognitive disease) 

Posypanova GA, Severin SE, Kondratyev AD. Effect of 

protein kinase modulators on the induction of 

morphological differentiation of pheochromocytoma PC12 

cells by nerve and fibroblast growth factors. Biotechnol 

Appl Biochem. 1990;12(1):20-7. Non-berry 

Rabin BM, ShukittHale B, Szprengiel A, Joseph JA. 

Effects of heavy particle irradiation and diet on 

amphetamine- and lithium chloride-induced taste avoidance 

learning in rats. Brain Res. 2002;953(1-2):31-6. Non-berry 

Ratty AK, Das NP. Effects of flavonoids on nonenzymatic 

lipid peroxidation: structure-activity relationship. Biochem 

Med Metab Biol. 1988;39(1):69-79. Non-berry chemical 

Ravaglia G, Forti P, Maioli F, Scali RC, Arnone G, 

Talerico T, Pantieri T, Nativio V, Mantovani V, Bianchin 

M. Common polymorphisms in methylenetetrahydrofolate 

reductase (MTHFR): relationships with plasma 

homocysteine concentrations and cognitive status in elderly 

northern italian subjects. Arch Gerontol Geriatr Suppl. 

2004;(9):339-48. No outcome of interest 

Ravaglia G, Forti P, Maioli F, Scali RC, Saccheitti L, 

Talerico T, Mantovani V, Bianchin M. Homocysteine and 

cognitive performance in healthy elderly subjects. Arch 

Gerontol Geriatr Suppl. 2005;(9):349-57. All normal 

cognition (correlation study) 

Ravaglia G, Forti P, Maioli F, Zanardi V, Dalmonte E, 

Grossi G, Cucinotta D, Macini P, Caldarera M. Blood 

homocysteine and vitamin B levels are not associated with 

cognitive skills in healthy normally ageing subjects.[see 

comment]. J Nutr Health Aging. 2000;4(4):218-22. N<100 

(B12 or Folate correlation) 

Regland B, Abrahamsson L, Blennow K, Gottfries CG, 

Wallin A. Vitamin B12 in CSF: reduced CSF/serum B12 

ratio in demented men. Acta Neurol Scand. 

1992;85(4):276-81. N<100 (excluding vascular and other) 

Regland B, Blennow K, Germgard T, KochSchmidt AC, 

Gottfries CG. The role of the polymorphic genes 

apolipoprotein E and methylene- tetrahydrofolate reductase 

in the development of dementia of the Alzheimer type. 

Dement Geriatr Cogn Disord. 1999;10(4):245-51. No 

outcome of interest 

Regland B, Gottfries CG, Oreland L. Vitamin B12-induced 

reduction of platelet monoamine oxidase activity in patients 

with dementia and pernicious anaemia. Eur Arch 

Psychiatry Clin Neurosci. 1991;240(4-5):288-91. No 

outcome of interest 

Richardson JS. Neuroprotective agents. Phys Med Rehabil 

Clin N Am. 1999;10(2):447-61. Review 

Riggs KM, Spiro A, Tucker K, Rush D. Relations of 

vitamin B-12, vitamin B-6, folate, and homocysteine to 

cognitive performance in the Normative Aging Study. Am 

J Clin Nutr. 1996. All normal cognition (correlation study) 

Roberge AG. Differentiation in brain and liver 

DOPA/5HTP decarboxylase activity after L-DOPA 

administration with or without pyridoxine in cats. J 

Neurochem. 1977;28(3):479-85. No outcome of interest 

Robertson DM, Manz HJ. Effect of thiamine deficiency on 

the competence of the blood-brain barrier to albumin 

labeled with fluorescent dyes. Am J Pathol. 

1971;63(3):393-402. Immature rats 

Robertson DM, Wasan SM, Skinner DB. Ultrastructural 

features of early brain stem lesions of thiamine-deficient 

rats. Am J Pathol. 1968;52(5):1081-97. Immature rats 

Robins Wahlin TB, Wahlin A, Winblad B, Backman L. 

The influence of serum vitamin B12 and folate status on 

cognitive functioning in very old age. Biol Psychol. 

2001;56(3):247-65. All normal cognition (correlation 

study) 
D-11 

Roos D, Willanger R. Various degrees of dementia in a 

selected group of gastrectomized patients with low serum 

B12. Acta Neurol Scand 55(5):363-76. 1977. N<100 (B12 

or Folate correlation) 

Roth A, Schaffner W, Hertel C. Phytoestrogen kaempferol 

(3,4',5,7-tetrahydroxyflavone) protects PC12 and T47D 

cells from beta-amyloid-induced toxicity. J Neurosci Res. 

1999;57(3):399-404. Non-berry chemical 

Sachdev P, Parslow R, Salonikas C, Lux O, Wen W, 

Kumar R, Naidoo D, Christensen H, Jorm A. 

Homocysteine and the brain in midadult life: evidence for 

an increased risk of leukoaraiosis in men. Arch Neurol. 

2004;61(9):1369-76. No B vitamin results 

Sachdev PS, Valenzuela M, Wang XL, Looi JC, Brodaty H. 

Relationship between plasma homocysteine levels and 

brain atrophy in healthy elderly individuals. Neurology. 

2002;58(10):1539-41. No B vitamin results 

Sagara Y, Vanhnasy J, Maher P. Induction of PC12 cell 

differentiation by flavonoids is dependent upon 

extracellular signal-regulated kinase activation. J 

Neurochem. 2004;90(5):1144-55. Non-berry chemical 

SamhanArias AK, MartinRomero FJ, GutierrezMerino C. 

Kaempferol blocks oxidative stress in cerebellar granule 

cells and reveals a key role for reactive oxygen species 

production at the plasma membrane in the commitment to 

apoptosis. Free Radic Biol Med. 2004;37(1):48-61. Nonberry chemical 

Saura CA, Tomita T, Davenport F, Harris CL, Iwatsubo T, 

Thinakaran G. Evidence that intramolecular associations 

between presenilin domains are obligatory for 

endoproteolytic processing. J Biol Chem. 

1999;274(20):13818-23. No outcome of interest 

Scalabrino G, Tredici G, Buccellato FR, Manfridi A. 

Further evidence for the involvement of epidermal growth 

factor in the signaling pathway of vitamin B12 (cobalamin) 

in the rat central nervous system. J Neuropathol Exp 

Neurol. 2000;59(9):808-14. Not B vitamin study 

Scapagnini G, Butterfield DA, Colombrita C, Sultana R, 

Pascale A, Calabrese V. Ethyl ferulate, a lipophilic 

polyphenol, induces HO-1 and protects rat neurons against 

oxidative stress. Antioxid Redox Signal. 2004;6(5):811-8. 

Non-berry chemical 

Schaper CG, Ansink BJ, Ploem JE. Subacute combined 

degeneration of the spinal cord and the vitamin B12 

metabolism, a clinical study. Clin Neurol Neurosurg. 

1979;81(1):26-38. Ineligible population (and/or no subanalysis of age-related neurocognitive disease) 

Schroecksnadel K, Leblhuber F, Frick B, Wirleitner B, 

Fuchs D. Association of hyperhomocysteinemia in 

Alzheimer disease with elevated neopterin levels. 

Alzheimer Dis Assoc Disord. 2004;18(3):129-33. N<100 

(B12 or Folate correlation) 

Schroeter H, Spencer JP, RiceEvans C, Williams RJ. 

Flavonoids protect neurons from oxidized low-densitylipoprotein-induced apoptosis involving c-Jun N-terminal 

kinase (JNK), c-Jun and caspase-3. Biochem J. 2001;358(Pt 

3):547-57. Non-berry chemical 

Schroeter H, Williams RJ, Matin R, Iversen L, RiceEvans 

CA. Phenolic antioxidants attenuate neuronal cell death 

following uptake of oxidized low-density lipoprotein. Free 

Radic Biol Med. 2000;29(12):1222-33. Non-berry chemical 

Schurr A, Payne RS, Miller JJ, Tseng MT, Rigor BM. 

Blockade of lactate transport exacerbates delayed neuronal 

damage in a rat model of cerebral ischemia. Brain Res. 

2001;895(1-2):268-72. Non-berry chemical 

Scott TM, Tucker KL, Bhadelia A, Benjamin B, Patz S, 

Bhadelia R, Liebson E, Price LL, Griffith J, Rosenberg I, 

Folstein MF. Homocysteine and B vitamins relate to brain 

volume and white-matter changes in geriatric patients with 

psychiatric disorders. Am J Geriatr Psychiatry. 

2004;12(6):631-8. Ineligible population (and/or no subanalysis of age-related neurocognitive disease) 

Selley ML, Close DR, Stern SE. The effect of increased 

concentrations of homocysteine on the concentration of 

(E)-4-hydroxy-2-nonenal in the plasma and cerebrospinal 

fluid of patients with Alzheimer's disease.[see comment]. 

Neurobiol Aging. 2002;23(3):383-8. N<100 (B12 or Folate 

correlation) 

Shea TB, Ashline D, Ortiz D, Milhalik S, Rogers E. The Sadenosyl homocysteine hydrolase inhibitor 3-deazaadenosine prevents oxidative damage and cognitive 

impairment following folate and vitamin E deprivation in a 

murine model of age-related, oxidative stress-induced 

neurodegeneration. Neuromolecular Med. 2005;5(2):171-

80. Combination B vitamin and other treatments 

Shea TB, Ortiz D, Rogers E. Differential susceptibity of 

transgenic mice lacking one or both apolipoprotein alleles 

to folate and vitamin E deprivation. J Alzheimers Dis. 

2004;6(3):269-73. Combination B vitamin and other 

treatments 

Shea TB, Ortiz D. 17 beta-estradiol alleviates synergistic 

oxidative stress resulting from folate deprivation and 

amyloid-beta treatment. J Alzheimers Dis. 2003;5(4):323-7. 

No outcome of interest 

Sheu KF, Calingasan NY, Lindsay JG, Gibson GE. 

Immunochemical characterization of the deficiency of the 

alpha-ketoglutarate dehydrogenase complex in thiaminedeficient rat brain. J Neurochem. 1998;70(3):1143-50. B 

vitamin antagonist 

Shirai N, Suzuki H. Effect of dietary docosahexaenoic acid 

and catechins on maze behavior in mice. Ann Nutr Metab. 

2004;48(1):51-8. Non-berry chemical 
D-12 

Shorvon SD, Carney MW, Chanarin I, Reynolds EH. The 

neuropsychiatry of megaloblastic anaemia. Br Med J. 

1980;281(6247):1036-8. N<100 (B12 or Folate correlation) 

Shutenko Z, Henry Y, Pinard E, Seylaz J, Potier P, Berthet 

F, Girard P, Sercombe R. Influence of the antioxidant 

quercetin in vivo on the level of nitric oxide determined by 

electron paramagnetic resonance in rat brain during global 

ischemia and reperfusion. Biochem Pharmacol. 

1999;57(2):199-208. Non-berry chemical 

Singh A, Naidu PS, Kulkarni SK. Quercetin potentiates LDopa reversal of drug-induced catalepsy in rats: possible 

COMT/MAO inhibition. Pharmacology. 2003;68(2):81-8. 

Non-berry chemical 

Singh A, Naidu PS, Kulkarni SK. Reversal of aging and 

chronic ethanol-induced cognitive dysfunction by quercetin 

a bioflavonoid. Free Radic Res. 2003;37(11):1245-52. 

Non-berry chemical 

Sjogren M, Wikkelso C, Ostling S, Wallin A, Blennow K. 

Biological correlates of clinical subgroups of Alzheimer's 

disease. Dement Geriatr Cogn Disord. 2002;14(4):191-7. 

No B vitamin results 

Skaper SD, Fabris M, Ferrari V, Dalle CM, Leon A. 

Quercetin protects cutaneous tissue-associated cell types 

including sensory neurons from oxidative stress induced by 

glutathione depletion: cooperative effects of ascorbic acid. 

Free Radic Biol Med. 1997;22(4):669-78. Non-berry 

chemical 

Slanina P, Frech W, Bernhardson A, Cedergren A, 

Mattsson P. Influence of dietary factors on aluminium 

absorption and retention in the brain and bone of rats. Acta 

Pharmacol Toxicol . 1985;56(4):331-6. No outcomes of 

interest 

Small BJ, Backman L. Predictors of longitudinal changes in 

memory, visuospatial, and verbal functioning in very old 

demented adults. Dement Geriatr Cogn Disord. 

1998;9(5):258-66. No B vitamin results 

Small BJ, Viitanen M, Winblad B, Backman L. Cognitive 

changes in very old persons with dementia: the influence of 

demographic, psychometric, and biological variables. J 

Clin Exp Neuropsychol. 1997. N<100 (B12 or Folate 

correlation) 

Smidt LJ, Cremin FM, Grivetti LE, Clifford AJ. Influence 

of thiamin supplementation on the health and general wellbeing of an elderly Irish population with marginal thiamin 

deficiency. J Gerontol. 1991;46(1):M16-22. No outcome of 

interest 

Sneath P, Chanarin I, Hodkinson HM, McPherson CK, 

Reynolds EH. Folate status in a geriatric population and its 

relation to dementia. Age Ageing. 1973. No outcome of 

interest 

Sohn YT, Oh JH. Characterization of physicochemical 

properties of ferulic acid. Arch Pharm Res. 

2003;26(12):1002-8. Non-berry chemical 

Soliman KF, Mazzio EA. In vitro attenuation of nitric 

oxide production in C6 astrocyte cell culture by various 

dietary compounds. Proc Soc Exp Biol Med. 

1998;218(4):390-7. Non-berry 

Soliman KF. Polyphenols, flavonoids, food constituents 

and oils attenuate neurodegenerative process. Ethn Dis. 

2001;11(1):165-6. Review 

Sommer BR, Wolkowitz OM. RBC folic acid levels and 

cognitive performance in elderly patients: a preliminary 

report. Biol Psychiatry. 1998;24(3):352-4. N<100 (B12 or 

Folate correlation) 

Spencer JP, RiceEvans C, Williams RJ. Modulation of prosurvival Akt/protein kinase B and ERK1/2 signaling 

cascades by quercetin and its in vivo metabolites underlie 

their action on neuronal viability. J Biol Chem. 

2003;278(37):34783-93. Non-berry chemical 

Spencer JP, Schroeter H, Crossthwaithe AJ, Kuhnle G, 

Williams RJ, RiceEvans C. Contrasting influences of 

glucuronidation and O-methylation of epicatechin on 

hydrogen peroxide-induced cell death in neurons and 

fibroblasts. Free Radic Biol Med. 2001;31(9):1139-46. 

Non-berry chemical 

Spindler AA, Renvall MA. Nutritional status and 

psychometric test scores in cognitively impaired elders. 

Ann N Y Acad Sci. 1989;561:167-77. N<100 (B12 or 

Folate correlation) 

Steiner H, Revesz T, Neumann M, Romig H, Grim MG, 

Pesold B, Kretzschmar HA, Hardy J, Holton JL, 

Baumeister R, Houlden H, Haass C. A pathogenic 

presenilin-1 deletion causes abberrant Abeta 42 production 

in the absence of congophilic amyloid plaques. J Biol 

Chem. 2001;276(10):7233-9. Not B vitamin study 

Suarez J, Herrera MD, Marhuenda E, PerezGuerrero C. 

Effect of hesperidin and neohesperidin dihydrochalcone on 

central nervous system. Fitoterapia. 1996. Non-berry 

chemical 

Summanen J, Vuorela P, Rauha JP, Tammela P, Marjamaki 

K, Pasternack M, Tornquist K, Vuorela H. Effects of 

simple aromatic compounds and flavonoids on Ca2+ fluxes 

in rat pituitary GH(4)C(1) cells. Eur J Pharmacol. 

2001;414(2-3):125-33. Non-berry chemical 

Sweeney MI, Kalt W, MacKinnon SL, Ashby J, 

GottschallPass KT. Feeding rats diets enriched in lowbush 

blueberries for six weeks decreases ischemia-induced brain 

damage. Nutr Neurosci. 2002;5(6):427-31. No outcomes of 

interest 
D-13 

Tabet N, Mantle D, Walker Z, Orrell M. Vitamins, trace 

elements, and antioxidant status in dementia disorders. Int 

Psychogeriatr. 2001;13(3):265-75. Cross-sectional intake 

study of patients with dementia 

Takahashi K, Fukuda M, Nakamura H. Subacute combined 

degeneration of the spinal cord with normal absorption of 

vitamin B12. Yonago Acta Med. 1969;13(2):145-51. Case 

report 

Tall JM, Seeram NP, Zhao C, Nair MG, Meyer RA, Raja 

SN. Tart cherry anthocyanins suppress inflammationinduced pain behavior in rat. Behav Brain Res. 

2004;153(1):181-8. Non-berry 

Tarabal O, Caldero J, Llado J, Oppenheim RW, Esquerda 

JE. Long-lasting aberrant tubulovesicular membrane 

inclusions accumulate in developing motoneurons after a 

sublethal excitotoxic insult: a possible model for neuronal 

pathology in neurodegenerative disease. J Neurosci. 

2001;21(20):8072-81. No outcome of interest 

Tarnopolsky MA, Beal MF. Potential for creatine and other 

therapies targeting cellular energy dysfunction in 

neurological disorders. Ann Neurol. 2001;49(5):561-74. 

Review 

Teunissen CE, Blom AH, Van Boxtel MP, Bosma H, de 

Bruijn C, Jolles J, Wauters BA, Steinbusch HW, de Vente 

J. Homocysteine: a marker for cognitive performance? A 

longitudinal follow-up study. J Nutr Health Aging. 

2005;7(3):153-9. All normal cognition (correlation study) 

Thomas DE, ChungAOn KO, Dickerson JW, Tidmarsh SF, 

Shaw DM. Tryptophan and nutritional status of patients 

with senile dementia. Psychol Med. 1986;16(2):297-305. 

N<50 (Food frequency questionnaire) 

Toda S. Inhibitory effects of phenylpropanoid metabolites 

on copper-induced protein oxidative modification of mice 

brain homogenate, in vitro. Biol Trace Elem Res. 

2002;85(2):183-8. Non-berry chemical 

Todd KG, Butterworth RF. Evaluation of the role of 

NMDA-mediated excitotoxicity in the selective neuronal 

loss in experimental Wernicke encephalopathy. Exp 

Neurol. 1998;149(1):130-8. B vitamin antagonist 

Torres I, Smith WT, Oxnard C. Degeneration of the 

peripheral and central nervous system in vitamin-B12-

deficient monkeys. Experientia. 1969;25(3):273-5. No 

outcome of interest 

Torronen R, Maatta K. Bioactive substances and health 

benefits of strawberries. Acta Hortic. 2002. Review 

Tsai TH, Lee CH, Yeh PH. Effect of P-glycoprotein 

modulators on the pharmacokinetics of camptothecin using 

microdialysis. Br J Pharmacol. 2001;134(6):1245-52. Nonberry chemical 

Tucker DM, Penland JG, Sandstead HH, Milne DB, Heck 

DG, Klevay LM. Nutrition status and brain function in 

aging. Am J Clin Nutr. 1990;52(1):93-102. No outcome of 

interest 

Turchan J, Pocernich CB, Gairola C, Chauhan A, Schifitto 

G, Butterfield DA, Buch S, Narayan O, Sinai A, Geiger J, 

Berger JR, Elford H, Nath A. Oxidative stress in HIV 

demented patients and protection ex vivo with novel 

antioxidants. Neurology. 2003;60(2):307-14. Non-berry 

chemical 

van Duyn MAS, Pivonka E. Overview of the health 

benefits of fruit and vegetable consumption for the dietetics 

professional: selected literature. J Am Diet Assoc. 2000. 

Review 

van Meeteren ME, Hendriks JJ, Dijkstra CD, van Tol EA. 

Dietary compounds prevent oxidative damage and nitric 

oxide production by cells involved in demyelinating 

disease. Biochem Pharmacol. 2004;67(5):967-75. Nonberry chemical 

Van Wymelbeke V, Guedon A, Maniere D, Manckoundia 

P, Pfitzenmeyer P. A 6-month follow-up of nutritional 

status in institutionalized patients with Alzheimer's disease. 

J Nutr Health Aging. 2004. No outcome of interest 

Ventura P, Panini R, Verlato C, Scarpetta G, Salvioli G. 

Hyperhomocysteinemia and related factors in 600 

hospitalized elderly subjects. Metabolism. 

2001;50(12):1466-71. No B vitamin results 

Vermeulen EGJ, Stehouwer CDA, Valk J, Knaap Mvd, 

Berg Mvd, Twisk JWR, Prevoo W, Rauwerda JA. Effect of 

homocysteine-lowering treatment with folic acid plus 

vitamin B6 on cerebrovascular atherosclerosis and white 

matter abnormalities as determined by MRA and MRI: a 

placebo-controlled, randomized trial. Eur J Clin Invest. 

2005. No outcome of interest 

Vietri M, Vaglini F, Cantini R, Pacifici GM. Quercetin 

inhibits the sulfation of r(-)-apomorphine in human brain. 

Int J Clin Pharmacol Ther. 2003;41(1):30-5. Non-berry 

chemical 

Volk C, Kempski B, Kempski OS. Inhibition of lactate 

export by quercetin acidifies rat glial cells in vitro. 

Neurosci Lett. 1997;223(2):121-4. Non-berry chemical 

Wahlin A, Hill RD, Winblad B, Backman L. Effects of 

serum vitamin B12 and folate status on episodic memory 

performance in very old age: a population-based study. 

Psychol Aging. 1996;11(3):487-96. All normal cognition 

(correlation study) 

Wang B, Foo L, Polya GM. Differential inhibition of 

eukaryote protein kinases by condensed tannins. 

Phytochemistry. 1996. No outcomes of interest 
D-14 

Wang CN, Chi CW, Lin YL, Chen CF, Shiao YJ. The 

neuroprotective effects of phytoestrogens on amyloid beta 

protein-induced toxicity are mediated by abrogating the 

activation of caspase cascade in rat cortical neurons. J Biol 

Chem. 2001;276(7):5287-95. 2001 Non-berry chemical 

Wang H, Joseph JA. Structure-activity relationships of 

quercetin in antagonizing hydrogen peroxide-induced 

calcium dysregulation in PC12 cells. Free Radic Biol Med. 

1999;27(5-6):683-94. Non-berry chemical 

Watkins SE, Thomas DE, Clifford M, Tidmarsh SF, 

Sweeney AE, AhSing E, Dickerson JW, Cowie VA, Shaw 

DM. Plasma amino acids in patients with senile dementia 

and in subjects with Down's syndrome at an age vulnerable 

to Alzheimer changes. J Ment Defic Res. 1989;33 ( Pt 

2):159-66. No B vitamin results 

Weeks BS, Wilson PJ, Heffernan CC, Gorra VA, White 

LE, Ahmad A. Laminin stimulates protein tyrosine 

dephosphorylation in PC12 cells. Biochem Biophys Res 

Commun. 1999;262(3):713-9. Non-berry chemical 

Wenk GL, McGannGramling K, HaussWegrzyniak B, 

Ronchetti D, Maucci R, Rosi S, Gasparini L, Ongini E. 

Attenuation of chronic neuroinflammation by a nitric 

oxide-releasing derivative of the antioxidant ferulic acid. J 

Neurochem. 2004;89(2):484-93. Non-berry chemical 

Whalley LJ, Staff RT, Murray AD, Duthie SJ, Collins AR, 

Lemmon HA, Starr JM, Deary IJ. Plasma vitamin C, 

cholesterol and homocysteine are associated with grey 

matter volume determined by MRI in non-demented old 

people. Neurosci Lett. 2003;341(3):173-6. No outcome of 

interest 

Widner B, Leblhuber F, Frick B, Laich A, ArtnerDworzak 

E, Fuchs D. Moderate hyperhomocysteinaemia and 

immune activation in Parkinson's disease. J Neural Transm. 

2002;109(12):1445-52. No outcome of interest 

Willis L, Bickford P, Zaman V, Moore A, Granholm AC. 

Blueberry extract enhances survival of intraocular 

hippocampal transplants. Cell Transplant. 2005. No 

outcomes of interest 

Woo J. Relationships among diet, physical activity and 

other lifestyle factors and debilitating diseases in the 

elderly. Eur J Clin Nutr. 2000;54 Suppl 3:S143-7. Review 

Wu BY, Yu AC. Quercetin inhibits c-fos, heat shock 

protein, and glial fibrillary acidic protein expression in 

injured astrocytes. J Neurosci Res. 2000;62(5):730-6. Nonberry chemical 

Xu YF, Zhang YJ, Zhang AH, Zhang Q, Wu T, Wang JZ. 

Attenuation of okadaic acid-induced hyperphosphorylation 

of cytoskeletal proteins by heat preconditioning and its 

possible underlying mechanisms. Cell Stress & 

Chaperones. 2004;9(3):304-12. Non-berry chemical 

Yagyu K, Kitagawa K, Wu B, Zhang NY, Irie T, Hattori N, 

Inagaki C. Protective effects of estradiol against amyloid 

beta protein-induced inhibition of neuronal Cl(-)-ATPase 

activity. Neuropharmacology. 2002;43(8):1297-304. Nonberry chemical 

Yan JJ, Cho JY, Kim HS, Kim KL, Jung JS, Huh SO, Suh 

HW, Kim YH, Song DK. Protection against beta-amyloid 

peptide toxicity in vivo with long-term administration of 

ferulic acid. Br J Pharmacol. 2001;133(1):89-96. Non-berry 

chemical 

Yang XJ, Kow LM, Funabashi T, Mobbs CV. 

Hypothalamic glucose sensor: similarities to and 

differences from pancreatic beta-cell mechanisms. 

Diabetes. 1999;48(9):1763-72. Non-berry chemical 

Youdim KA, Martin A, Joseph JA. Incorporation of the 

elderberry anthocyanins by endothelial cells increases 

protection against oxidative stress. Free Radic Biol Med. 

2000;29(1):51-60. No outcomes of interest 

Youdim KA, McDonald J, Kalt W, Joseph JA. Potential 

role of dietary flavonoids in reducing microvascular 

endothelium vulnerability to oxidative and inflammatory 

insults (small star, filled). J Nutr.Biochem. 2002;13(5):282-

8. No outcomes of interest 

Youdim KA, ShukittHale B, Joseph JA. Flavonoids and the 

brain: interactions at the blood-brain barrier and their 

physiological effects on the central nervous system. Free 

Radic Biol Med. 2004;37(11):1683-93. Review 

Youdim KA, ShukittHale B, MacKinnon S, Kalt W, Joseph 

JA. Polyphenolics enhance red blood cell resistance to 

oxidative stress: in vitro and in vivo. Biochim Biophys 

Acta. 2000;1523(1):117-22. No outcomes of interest 

Yukawa M, Naka H, Murata Y, Katayama S, Kohriyama T, 

Mimori Y, Nakamura S. Folic acid-responsive neurological 

diseases in Japan. J Nutr Sci Vitaminol. 2001;47(3):181-7. 

Ineligible population (and/or no sub-analysis of age-related 

neurocognitive disease) 

ZapataTorres G, Opazo F, Salgado C, Munoz JP, 

Krautwurst H, Mascayano C, SepulvedaBoza S, Maccioni 

RB, Cassels BK. Effects of natural flavones and flavonols 

on the kinase activity of Cdk5. J Nat Prod. 2004;67(3):416-

20. Non-berry chemical 

Zelaya FO, Rose SE, Nixon PF, Wholohan BT, Bower AJ, 

Zimitat C, Schoutrop J, Doddrell DM. MRI demonstration 

of impairment of the blood-CSF barrier by glucose 

administration to the thiamin-deficient rat brain. Magn 

Reson Imaging. 1995;13(4):555-61. Mixed B vitamin with 

other treatments (glucose) 

Zensho H, Nishida A, Shimizu M, Uchitomi Y, Yamawaki 

S. Heat shock protein 72 restores cyclic AMP accumulation 

after heat shock in N18TG2 cells. Brain Res. 1998;790(1-

2):278-83. Non-berry chemical 
D-15 

Zhao Y, Gao Z, Li H, Xu H. Hemin/nitrite/H(2)O(2) 

induces brain homogenate oxidation and nitration: effects 

of some flavonoids. Biochim Biophys Acta. 2004;1675(1-

3):105-12. Non-berry chemical 

Zheng J, Ramirez VD. Inhibition of mitochondrial proton 

F0F1-ATPase/ATP synthase by polyphenolic 

phytochemicals. Br J Pharmacol. 2000;130(5):1115-23. 

Non-berry chemical 

Zhou A, Matsumoto T, Farver O, Thorn NA. Uptake of 

ascorbic acid by freshly isolated cells and secretory 

granules from the intermediate lobe of ox hypophyses. Acta 

Physiol Scand. 1990;138(2):229-34. Non-berry chemical 

Zhu M, Phillipson JD, Greengrass PM, Bowery NE, Cai Y. 

Plant polyphenols: biologically active compounds or nonselective binders to protein? Phytochemistry. 1997. Nonberry chemical 

Zhu M, Rajamani S, Kaylor J, Han S, Zhou F, Fink AL. 

The flavonoid baicalein inhibits fibrillation of alphasynuclein and disaggregates existing fibrils. J Biol Chem. 

2004;279(26):26846-57. Non-berry chemical 

Zielasek J, Muller B, Hartung HP. Inhibition of cytokineinducible nitric oxide synthase in rat microglia and murine 

macrophages by methyl-2,5-dihydroxycinnamate. 

Neurochem Int. 1996;29(1):83-7. Non-berry chemical 
E-1

Appendix E. Peer Reviewers 

We gratefully acknowledge the following individuals who reviewed the initial draft of this 

Report and provided us with constructive feedback. Acknowledgments are made with the 

explicit statement that this does not constitute endorsement of the report. 

 

David Atkins, MD, MPH 

Chief Medical Officer 

Center for Outcomes and Evidence 

Agency for Healthcare Research and Quality 

Rockville, MD 

Tsunenobu Tamura, M.D 

Professor, Department of Nutrition Sciences 

Division of Molecular Nutrition & Genetics 

University of Alabama School of Health Related 

Professions 

Birmingham, AL 

 

Alice H. Lichtenstein, DSc 

Stanley N. Gershoff Professor of Nutrition 

Science and Policy 

Gerald J. and Dorothy R. Friedman School of 

Nutrition Science and Policy at Tufts 

University 

Senior Scientist, Director of the 

Cardiovascular Nutrition Laboratory 

Jean Mayer USDA Human Nutrition 

Research Center on Aging at Tufts 

University 

Boston, Massachusetts 

(Also a Technical Expert Panel member) 

Comments from the Office of Dietary 

Supplements, National Institutes of Health 

coordinated through 

Anne Thurn, PhD 

Director 

Evidence-Based Review Program 

Office of Dietary Supplements 

National Institutes of Health 

Bethesda, Maryland 

 

Ronald L. Prior, Ph.D. 

Agricultural Research Service Scientist 

United States Department of Agriculture 

Arkansas Children’s Nutrition Center 

Little Rock, AR 

Nicholi Vorsa, PhD 

Research Professor 

Plant Science 

Marucci Blueberry-Cranberry Research Center 

Plant Science/Chatsworth 

Chatsworth, New Jersey 

(Also a Technical Expert Panel member) 

 

Henry W. Querfurth, MD, PhD 

Associate Professor of Neurology and 

Neuroscience 

Tufts University School of Medicine 

Chief, Neurology Research 

Caritas St. Elizabeth’s Medical Center 

Boston, Massachusetts 

(Also a Technical Expert Panel member) 

Other Technical Expert Panel members also provided oral feedback and recommendations.