Effect of low doses of 5-methyltetrahydrofolate and folic acid on plasma homocysteine in healthy subjects with or without the 677CT polymorphism of methylenetetrahydrofolate reductase
Sorry about the long title…This study compares the use of folic acid to 5-methyl THF, the active form of folic acid (after being converted by MTHFR). Both showed similar effects at lowering homocysteine. However, the interesting effect here is that, in patients with two sluggish copies of the enzyme MTHFR, 5-methyl THF showed continued lowering of homocysteine 6 month after cessation of supplementation. This suggests that 5-methyl THF supplementation somehow changed the phenotypic expression related to folic acid metabolism.