Iron Deficiency, Depression, and Other Affective Disorders in Female State Fair Attendees
Conditions: Iron-deficiency, Iron Deficiency Anemia, Iron Deficiency (Without Anemia)
Sponsor: University of Minnesota

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Non-Anemic Iron Deficiency, Depression, and other Health Issues  
In State Fair Attendees 
 
 
Funding Request - $12,500 
Contact person: Daniel D. Gallaher, Ph.D., Professor, Department of Food Science and Nutrition, 1334 Eckles 
Ave., University of Minnesota, St. Paul, MN. Telephone: 612-624-0746, Email: dgallahe@umn.edu 
 
Principal Investigator: Daniel D. Gallaher, Ph.D., Professor, Department of Food Science and Nutrition, 1334 
Eckles Ave., University of Minnesota, St. Paul, MN. Telephone: 612-624-0746, Email: dgallahe@umn.edu 
 
Key Personnel: 
Sabrina P. Trudo, Ph.D., Co-Investigator, Associate Professor, Department of Food Science and Nutrition 
University of Minnesota. Has extensive human studies experience, and therefore will assist in preparation of IRB 
forms, trial design, and appropriate approaches to working with human subjects in the environment of the State 
Fair. 
 
Joannie Dobbs, Ph.D., Co-Investigator, Assistant Specialist For Food Composition and Health Education, 
Department of Human Nutrition, Food and Animal Sciences, University of Hawaii at Manoa. Will assist with 
development of the survey and will analyze survey results and participate in statistical analysis. 
 
 
 
 

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Abstract 
Depression is a serious disorder that significantly diminishes quality of life and is a leading cause of disability 
worldwide. It is a common disorder that is estimated to have a 12-month prevalence in the United States of 
10%. It is significantly associated with numerous chronic diseases, including arthritis, asthma, cancer, 
cardiovascular disease, diabetes, and chronic pain conditions. There is evidence suggesting that, in some cases, 
there is a causal relationship between depression and these physical ailments. People with depression are at 
high risk for early death, due to both a greater risk of suicide and the chronic diseases they experience. Thus, 
reducing the prevalence of depression would constitute a significant advancement in public health. Recent 
evidence suggests that depression may result, in some cases, from a nutritional deficiency, specifically iron 
deficiency. Iron deficiency is the most common of all nutritional deficiencies. It is estimated that as many as 70% 
of the world’s population has inadequate iron status, and that 30% of the population has iron-deficiency 
anemia. Iron deficiency is the only nutritional deficiency that is common in both developing and developed 
countries. It has long been known that iron deficiency in young children can lead to permanent impairments in 
cognitive function, thus establishing the importance of iron in neurological function. However, recent evidence 
suggests that iron deficiency is also associated with depression, perhaps long before the routinely monitored 
clinical parameters indicate iron-deficiency anemia. Indeed, we have preliminary evidence that individuals who 
have low iron status, but are not sufficiently iron deficient to be anemic (referred to as non-anemic iron 
deficiency, NAID), show a much greater likelihood of being depressed than those with normal iron status. Thus, 
the overall goal of our research project is to examine rigorously the relationship between iron status and 
depression. It is our hypothesis that individuals who have NAID will have a much greater prevalence of 
depression than those with normal iron status. To test this hypothesis, we will recruit attendees of the 
Minnesota State Fair to donate a small amount of blood, to be used to assess iron status, and to take a survey 
that will assess their degree of depression, using a validated survey instrument. The primary measures of iron 
status will be the less commonly monitored but earlier indicators of iron deficiency: plasma ferritin and plasma 
transferrin receptor, which are measured by ELISA. Together, these two measures can be used to calculate total 
body iron, which is now regarded as the most accurate measure of iron status. We will also measure 
hemoglobin, the more routinely monitored indicator of iron status clinically, to determine whether the 
individuals are anemic. We will then correlate the degree of depression with total body iron to determine the 
association. Finding an association between low iron status and depression would suggest that a relatively 
straightforward and inexpensive treatment exists that could greatly reduce the prevalence of depression, 
namely improving iron status. If our hypothesis is correct, then a dramatic decrease in this debilitating condition 
could be achieved for Minnesotans. 
 
 
 
 
 
 

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Specific Aims 
The specific aims of the proposed research are to determine in a large and varied group of State Fair attendees 
the following: 
1. Their iron nutritional status, to be determined by measurement of their plasma ferritin and transferrin 
receptor concentrations. 
2. Their degree of depression, using the PHQ-9 depression screen, a validated instrument for measuring 
depression, as well as fatigue and other health issues that we suspect are related to low iron status. 
Our hypothesis is that iron deficiency that is not severe enough to result in anemia (and therefore is not 
commonly diagnosed) is strongly associated with depression. Further, it will also be associated with greater 
fatigue as well as other conditions not normally associated with iron deficiency. 
Background and significance 
Iron deficiency is the most common nutritional deficiency in the world, affecting an estimated 2 billion people 
(1). It is the only nutritional deficiency that is common both in developing and developed countries.  In the USA, 
it is estimated that 9-11% of non-pregnant premenopausal women have iron deficiency anemia (2). 
Iron deficiency is best known for the fatigue and lassitude that accompanies it. This most commonly occurs 
when the individual develops iron deficiency anemia (defined as a low hemoglobin concentration or a low 
hematocrit). However, there is growing evidence in the literature that there may be pathophysiological 
processes and symptoms of iron deficiency long before an individual becomes anemic. For example, in a study of 
non-anemic women with unexplained fatigue, iron supplementation for one month reduced fatigue 29% versus 
a reduction in fatigue of 13% in women given a placebo (3). This situation of subclinical iron deficiency, often 
referred to as non-anemic iron deficiency (NAID), is quite likely common and is certainly far more common than 
iron deficiency anemia. NAID is underdiagnosed due to the more sophisticated testing needed to diagnose it, 
thus making it much harder for people to connect symptoms with iron deficiency. For example, in a study 
conducted in the Netherlands, the prevalence of NAID was estimated at between 14% in men and 9% in women, 
using serum ferritin as the measure of iron status (4).  
Iron deficiency during childhood development can lead to impairments in cognitive development (5), thus 
establishing the potential of iron deficiency to have detrimental neuropsychological consequences.  One such 
consequence, depression, is a serious mood disorder that significantly diminishes quality of life and is a leading 
cause of disability worldwide (6). Although an association between iron deficiency anemia and depression has 
been reported (7), the relationship between the much more common NAID and depression is unexplored. 
However, we have recently obtained preliminary evidence that NAID is also associated with depression. In a 
laboratory class taught by one of us (DDG), we assessed iron status using several different measures, including 
plasma ferritin. A value of <15 ng/mL for plasma ferritin is indicative of low iron status. We found that 48% of 
female students with ferritin values of 1-10 ng/mL reported feeling sad or depressed in the last 3 months, 
whereas 21% of students with ferritin between 11-20 ng/mL reported sadness or depression, and only 4% with 
serum ferritin between 21-30 ng/mL reported sadness or depression. Of note was that none of these female 
students were anemic. Thus, our findings suggest that depression may be highly prevalent in NAID. 
Who in the community will benefit from the results of our project? 
Depression can increase work absenteeism, lead to short-term disability, and decrease productivity. Further, 
depression can adversely affect the outcome for a number of chronic diseases, thus increasing the cost of 

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treatment. Thus, untreated depression has a significant negative societal impact. Depression in Minnesota is 
estimated at 5.9% of the population, which is relatively low compared to other states (8). However, this still 
represents a significant proportion of the state population to be afflicted with a debilitating condition. A finding 
that low iron status is associated with depression suggests that depression may be treated in an inexpensive and 
straightforward manner, by increasing iron intake, either through diet or with supplements. 
Partnership 
This project is a partnership between two investigators at the University of Minnesota (Gallaher and Trudo) and 
an investigator at the University of Hawaii (Dobbs). Dr. Gallaher has extensive experience in determining iron 
status in humans, although only in an academic environment (i.e. the classroom). Dr. Trudo has significant 
experience conducting human trials. Dr. Dobbs has considerable experience in analysis of survey data and has a 
considerable understanding of the relationship between NAID and various health conditions. These three 
investigators bring together considerable and complimentary experience for conducting the proposed study.  
Project design and methods  
Male and female subjects between the ages of 18 and 85 will be invited to complete a computer-based survey 
that uses a validated instrument to assess depression, as well as other health issues suspected to occur with 
NAID, including fatigue. Subsequently, 300 µL of blood will be collected by professional phlebotomists from each 
subject using minimally invasive capillary blood collectors (i.e., finger sticks, essentially). The surveys and blood 
samples will be coded to ensure confidentiality. The blood will be analyzed for whole blood hemoglobin, plasma 
ferritin, and plasma transferrin receptor (TfR) concentration. Plasma ferritin and TfR will be measured by ELISA, 
and will be used to calculate total body iron (9). Hemoglobin will be measured by a spectrophotometric method. 
We will then correlate total body iron with the scores from the depression and fatigue survey instruments to 
determine whether, in subjects that are not anemic (hemoglobin within normal range), total body iron 
correlates with depression as well as with the other measures we will examine using the survey. 
Drs. Gallaher and Trudo will oversee the project at the State Fair. Graduate students will be hired to assist in 
administering the electronic survey. Professional phlebotomists will be hired to collect blood from the subjects. 
We plan on having two graduate students and two phlebotomists working at the Fair at any given time. Our goal 
is to enroll 200 subjects over 2 days. 
Next steps 
We plan to disseminate our project findings initially by presenting the results at the Experimental Biology 
meetings, the main nutrition research meeting in the United States. Subsequently, we would aim to publish the 
findings in a journal that focuses on clinical nutrition. 
If our hypothesis is correct, and we find that subjects with low iron status, as measured by total body iron, have 
a much greater prevalence of depression, we believe there will be a number of agencies who would sponsor 
further research. These would include NIH, USDA, and the National Cattlemen’s Beef Association. Our next step 
would be to conduct an intervention study, in which we would identify individuals with low iron status who are 
depressed and intervene to determine whether improving their iron status resolves their depression.  
If an iron intervention proves successful in resolving depression, it may then be appropriate to engage 
community health agencies to determine how to develop a public health message to spread this information to 
the community at large. This could include both county and state public health agencies. 

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Timeline 
Both the biochemical assay (ferritin, transferrin receptor, hemoglobin) and the survey results will be analyzed 
within the first 3 months after completion of the sample and data collection. During the next three months we 
will statistically analyze the data. The next 6 months will be devoted to writing a manuscript for publication. 
Biosketches 
See attached. 
Budget 
Item 
Estimated cost 
Phlebotomists 
640 
Graduate students 
710 
Technician for assays 
3600 
Survey analysis 
1500 
Transferrin Receptor kits 
3450 
Ferritin kits 
1300 
Miscellaneous supplies 
1300 
TOTAL 
12500 
 
 
 
 

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References 
1. 
Zimmermann, M.B., et al. (2007) Nutritional iron deficiency. Lancet, 370, 511-20. 
2. 
Scholl, T.O. (2005) Iron status during pregnancy: setting the stage for mother and infant. Am J Clin Nutr, 
81, 1218S-1222S. 
3. 
Verdon, F., et al. (2003) Iron supplementation for unexplained fatigue in non-anaemic women: double 
blind randomised placebo controlled trial. BMJ, 326, 1124. 
4. 
Baart, A.M., et al. (2013) High prevalence of subclinical iron deficiency in whole blood donors not 
deferred for low hemoglobin. Transfusion, 53, 1670-7. 
5. 
Grantham-McGregor, S., et al. (2001) A review of studies on the effect of iron deficiency on cognitive 
development in children. J Nutr, 131, 649S-666S; discussion 666S-668S. 
6. 
Ustun, T.B., et al. (2004) Global burden of depressive disorders in the year 2000. Br J Psychiatry, 184, 
386-92. 
7. 
Chen, M.H., et al. (2013) Association between psychiatric disorders and iron deficiency anemia among 
children and adolescents: a nationwide population-based study. BMC Psychiatry, 13, 161. 
8. 
Features, C. (2011) An Estimated 1 in 10 U.S. Adults Report Depression. 
http://www.cdc.gov/features/dsdepression/. Centers for Disease Control and Prevention, Atlanta, GA. 
9. 
Cook, J.D., et al. (2003) The quantitative assessment of body iron. Blood, 101, 3359-64.