Bioavailability of Folate From a Mixed Diet Using a Stable Isotope Method

Study Overview
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Brief Summary
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The main objectives of this project are: to determine the relative bioavailability of dietary folate from a total diet, compared with synthetic folic acid and to determine the bioavailability with a higher precision than previous methods. The hypothesis is that the bioavailability of dietary folate within a confidence interval of +/-20% can be estimated.

Detailed Description
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Folate plays a role in the prevention of certain birth defects and possibly also in prevention of neurocognitive diseases, cancer and cardiovascular disease. The proportion of dietary folate that is absorbed and becomes available for metabolic processes in the body has been estimated between 30 and 98%, but an accurate figure is lacking. Since subjects generally differ a lot in their folate or homocysteine response upon a change in dietary folate intake, the between-person variability in these responses is high. Therefore, bioavailability estimates derived from these responses have large confidence intervals. With this trial the researchers want to determine folate bioavailability with a higher precision than previous trials. A good estimate of folate bioavailability from the general diet is necessary to construct reliable dietary reference intakes for folate.

Official Title
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The Relative Bioavailability of Folate From a Mixed Diet Compared to Synthetic Folic Acid Using a Stable Isotope Method

Conditions
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Folate Bioavailability, Healthy

Intervention / Treatment
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* Behavioral: Controlled diet
* Behavioral: folic acid supplement
* Behavioral: 13C11-labelled folic acid supplement


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Serum B12 >118pmol/L; Serum creatinine <125micromol/L; Plasma total homocysteine <26micromol/L. Exclusion Criteria: Cardiovascular disease, cancer, rheumatoid arthritis, epilepsy, gastro-intestinal disorders; Use of drugs interfering with folate metabolism; Use of B vitamins within the period three months prior to the study. Body Mass Index (BMI) > 30

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Intervention/Treatment |
| --- |
|Behavioral: Controlled diet|nan|
|Behavioral: folic acid supplement|nan|
|Behavioral: 13C11-labelled folic acid supplement|nan|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Bioavailability based on change in labelled folate concentration in plasma; |  |  | 
| Bioavailability based on change in folate concentration in plasma |  |  | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Bioavailability based on change in concentration in plasma homocysteine |  |  | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Folate, Bioavailability, Stable isotopes