L-5-methyltetrahydrofolate vs folic acid on plasma homocysteine.
Oral folic acid needs to be converted by the enzyme MHTFR to 5-MTHF before it can be used by the body in the methylation pathways. As has been previously discussed in Updates, the enzyme MHTFR is a common site of genetic differences, with certain genotypes producing a very sluggish enzyme that does not readily activate the oral folic acid. The idea has been that, by giving 5-MHTF directly, you can bypass genetic defects. This study does not support this theory, but it was also done on normal patients without consideration of their genetic makeup.
AJCN — Abstracts: Venn et al. 77 (3): 658