Folate status response to controlled folate intake is affected by the methylenetetrahydrofolate reductase 677C-->T polymorphism in young women.

This study was designed to evaluate the effect of the methylenetetrahydrofolate reductase (MTHFR) 677C-->T polymorphism on folate and homocysteine response in non-Hispanic women consuming a low folate diet followed by a diet providing the Recommended Dietary Allowance (RDA) for folate. Women (aged 20-30 y old) with either the TT (n = 19) or CC (n = 22) MTHFR 677C-->T genotype participated in a folate depletion-repletion study (7 wk, 115 microg dietary folate equivalents (DFE)/d; 7 wk, 400 microg DFE/d). Overall serum folate decreased (P < 0.