Methylated Folate (L-Methylfolate) and MTHFR
Methylated folate (5-methyltetrahydrofolate, 5-MTHF) is the biologically active form of folate that participates directly in homocysteine remethylation, DNA synthesis, and the methylation reactions that matter most in early embryonic development. Most prenatal vitamins and fortified foods contain synthetic folic acid, not 5-MTHF. To become active, folic acid requires enzymatic conversion by methylenetetrahydrofolate reductase (MTHFR). Two common MTHFR gene variants, C677T and A1298C, reduce that enzyme's activity. Reduced activity means impaired folate metabolism. Impaired folate metabolism can raise homocysteine, increase thrombophilic risk, and contribute to recurrent pregnancy loss in affected individuals. This is not a rare edge case. MTHFR variants are common, and most patients who carry them have never been tested. RRM protocols specify L-methylfolate preconceptionally for women with known MTHFR variants, recurrent miscarriage, or elevated homocysteine. That means skipping the conversion step entirely and delivering the active form directly.
This content is for educational purposes only and does not constitute medical advice. Consult an RRM clinician or healthcare provider for guidance specific to your situation.