Response of serum and red blood cell folate concentrations to folic acid supplementation depends on methylenetetrahydrofolate reductase C677T genotype: Results from a crossover trial
Article first published online: 4 MAR 2013
© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Molecular Nutrition & Food Research
Special Issue: Folate and Health - Present and Future
Volume 57, Issue 4, pages 637–644, April 2013
How to Cite
Anderson, C. A. M., Beresford, S. A. A., McLerran, D., Lampe, J. W., Deeb, S., Feng, Z. and Motulsky, A. G. (2013), Response of serum and red blood cell folate concentrations to folic acid supplementation depends on methylenetetrahydrofolate reductase C677T genotype: Results from a crossover trial. Mol. Nutr. Food Res., 57: 637–644. doi: 10.1002/mnfr.201200108
- Issue published online: 3 APR 2013
- Article first published online: 4 MAR 2013
- Manuscript Accepted: 27 DEC 2012
- Manuscript Revised: 28 OCT 2012
- Manuscript Received: 16 FEB 2012
- National Institutes of Health, National Heart, Lung, and Blood Institute. Grant Number: R01 HL058138
- Folic acid;
- Methylenetetrahydrofolate reductase;
By increasing blood folate concentrations, folic acid supplementation reduces risk for neural tube defect-affected pregnancies, and lowers homocysteine concentrations. We assessed response of red blood cell (RBC) and serum folate to folic acid supplementation, and examined association of response with the genetic polymorphism C677T of the methylenetetrahydrofolate NAD(P)H (MTHFR) gene.
Methods and results
Randomized, controlled, crossover trial with two folic acid supplement treatment periods and a 30-week washout period. The primary outcome is blood folate (serum and RBC) concentrations. Volunteers (n = 142) aged 18–69 were randomized to two of three doses (0, 200, and 400 μg) of folic acid for 12 weeks. Serum folate response depended on treatment period with significant responses to 200 μg seen only in the second treatment periods (4.4 ng/mL or 3.4 ng/mL). Additionally, serum folate increased as folic acid dose increased to 400 μg (p < 0.01) and response was greater after the washout period (8.7 ng/mL), than after a 6-week run-in (2.3 ng/mL). The differential change attributable to a daily supplement of 400 μg compared to 200 μg was 96.8 ng/mL; while the change attributable to 400 μg compared to 0 μg was 121.4. Increases in RBC folate concentrations with 400 μg occurred within MTHFR gene mutation (C677T); and in the African American group.
Serum folate concentration is responsive to modest increases in folic acid intake. RBC folate increases only with higher additional doses of folic acid supplementation, and this is true for each MTHFR C677T genotype.