5-Methyltetrahydrofolate (5-MTHF)

5-Methyltetrahydrofolate (5-MTHF) is the primary biologically active, methylated form of folate (vitamin B9) found in blood and tissues. It is produced in the body by reduction and methylation of dietary folate or synthetic folic acid, via the enzyme methylenetetrahydrofolate reductase (MTHFR). 5-MTHF serves as the crucial methyl group donor in the remethylation of homocysteine to methionine, a step essential for cellular methylation reactions, DNA synthesis and repair, neurotransmitter production, and fetal development. Deficiency or impaired metabolism of 5-MTHF—particularly due to common polymorphisms in the MTHFR gene—can result in elevated homocysteine, with potential links to cardiovascular, neurodevelopmental, and neuropsychiatric disorders. Supplementation with L-methylfolate is sometimes used therapeutically, particularly in populations with known MTHFR mutations or absorption deficits.

Other names

MethylfolateMethyl-THFL-methylfolate5-methyl-THFN5-methylfolate5-methyltetrahydrofolic acidmethyl-H4FN5-CH3-THFPrefolic A

Provides methyl groups for conversion of homocysteine to methionine, supporting methylation cycles and DNA synthesis