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

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

The main objectives of this project are:

1. to determine the relative bioavailability of dietary folate from a total diet, compared with synthetic folic acid and
2. 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.

Study Overview

• Status: Completed
• Conditions: Healthy; Folate Bioavailability
• Intervention / Treatment: Behavioral: Controlled diet; Behavioral: folic acid supplement; Behavioral: 13C11-labelled folic acid supplement

Detailed Description

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.

• Study Type: Interventional
• Enrollment: 75
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Netherlands
  • Wageningen, Netherlands, 6700EV
    • Wageningen University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 60 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Bioavailability based on change in labelled folate concentration in plasma;
Bioavailability based on change in folate concentration in plasma

Secondary Outcome Measures

Outcome Measure
Bioavailability based on change in concentration in plasma homocysteine

Collaborators and Investigators

• Sponsor: Wageningen Centre for Food Sciences
• Collaborators: Wageningen University
• Investigators: Principal Investigator: Martijn Katan, Professor, Wageningen University; Principal Investigator: Petra Verhoef, Dr., Wageningen Centre for Food Sciences

Study record dates

Study Major Dates

• Study Start: May 1, 2005
• Study Completion: June 1, 2005

Study Registration Dates

• First Submitted: August 12, 2005
• First Submitted That Met QC Criteria: August 12, 2005
• First Posted (Estimate): August 15, 2005

Study Record Updates

• Last Update Posted (Estimate): October 4, 2005
• Last Update Submitted That Met QC Criteria: October 3, 2005
• Last Verified: August 1, 2005

More Information

Terms related to this study

• Keywords: Bioavailability; Folate; Stable isotopes
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Micronutrients; Vitamins; Hematinics; Folic Acid; Vitamin B Complex
• Other Study ID Numbers: A-007-RW