The main objectives of this project are: (I) to determine the relative bioavailability of dietary folate from a total diet, compared with synthetic folic acid and (II) to determine the bioavailability with a higher precision than previous methods. Our hypothesis is that we can estimate the bioavailability of dietary folate within a confidence interval of +/-20%.

Condition	Intervention
Folate Bioavailability	Behavior: Controlled diet  Behavior: folic acid supplement  Behavior: 13C11-labelled folic acid supplement

Further Study Details: 

Primary Outcomes: Bioavailability based on change in labelled folate concentration in plasma;; Bioavailability based on change in folate concentration in plasma.
Secondary Outcomes: Bioavailability based on change in concentration in plasma homocysteine.
Expected Total Enrollment:  75

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 we 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.

Ages Eligible for Study:  18 Years   -   60 Years,  Genders Eligible for Study:  Both

Accepts Healthy Volunteers

Criteria

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.
• BMI > 30

Netherlands
      Wageningen University, Wageningen,  6700EV,  Netherlands

Study chairs or principal investigators

Petra Verhoef, Dr.,  Principal Investigator,  Wageningen Centre for Food Sciences   
Martijn Katan, Professor,  Principal Investigator,  Wageningen University   

Study ID Numbers:  A-007-RW
Last Updated:  August 12, 2005
Record first received:  August 12, 2005
ClinicalTrials.gov Identifier:  NCT00130585
Health Authority: Netherlands: The Central Committee on Research Involving Human Subjects (CCMO)
ClinicalTrials.gov processed this record on 2005-08-23