Abstract: [Abstract]  Objective  To evaluate the effect of folic acid supplement in different 5,10-methylenetetrahydrofolate reductase (MTHFR) genotype. Methods    113 healthy women from Tianjin were divided into CC(24), CT(58), TT(31) groups according their MTHFR C677T genotype, then in each group subjects were randomly divided into intervention (400 μg/d folic acid supplement) and control(usual diet) groups. Plasma folate, red blood cell (RBC) folate, plasma Hcy concentration were measured at baseline and two months of intervention. Results   The plasma folate was lower (P = 0.003, P = 0.015), and the plasma Hcy was higher (P <0.001, P <0.001) in the TT genotype than that in the CC/CT genotype. After two months of intervention, the plasma folate, RBC folate concentration increased while the plasma Hcy concentration decreased in all three intervention groups. Although the plasma Hcy concentration decreased most in TT genotype, the final average concentration is still larger than 10umol/L (10.09 ± 1.30umol/L). Logistic regression analysis showed that the MTHFR CT, TT genotype was a risk factor of high Hcy concentration, OR=8.078, 95%CI: 1.929-33.834; folic acid supplementation can reduce the risk of high Hcy concentration, OR =0.465, 95%CI: 0.189-1.146. Conclusion   Folic acid supplement can significantly increase plasma folate and red cell folate concentration, and reduce plasma Hcy concentration in all MTHFR genotypes. However, women with TT genotype might need to take longer or higher dose of folic acid.

Key words: 10-methylenetetrahydrofolate reductase (FADH2), folic acid, homocysteine, Genotype, intervention study, women