Response of serum and red blood cell folate concentrations to folic acid supplementation depends on methylenetetrahydrofolate reductase C677T genotype: results from a crossover trial
Anderson CA, Beresford SA, McLerran D, Lampe JW, Deeb S, Feng Z, et al.
Published in Mol Nutr Food Res, Vol. 57 (4), pp. 637-44
Methodology
Randomised, double-blind, controlled crossover trial in 142 volunteers aged 18-69. Each received two of three folic acid doses (0, 200 or 400 mcg/day) for 12 weeks per period, separated by a 30-week washout; serum and red blood cell (RBC) folate were the primary outcomes, analysed by MTHFR C677T genotype.
Key Findings
Serum folate rose as the folic acid dose rose to 400 mcg/day (p < 0.01). RBC folate rose only with the higher added dose, and the increase with 400 mcg/day was seen within each MTHFR C677T genotype.
Conclusions
Blood folate responds to modest folic acid intakes, and RBC folate rises with 400 mcg/day in every C677T genotype, including TT.
Limitations
Modest sample split across three genotypes and two periods; a period effect complicated the serum response; blood folate is a status marker, not a clinical outcome.
Supplements Studied
this is true for each MTHFR C677T genotype
Related Health Concerns
Study Details
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