L-5-Methyltetrahydrofolate (L-Methylfolate, free acid)
L-5-Methyltetrahydrofolate (L-Methylfolate, free acid) is a tier 1 form of Folate (Vitamin B9), used in 408 on-market products .
408
on-market products
tier 1
quality tier
n/a
elemental fraction
Why this tier: The natural, circulating, already-"active" form that bypasses the MTHFR conversion step entirely; raised serum folate more effectively than folic acid in an RCT, though that trial found no additional miscarriage-prevention benefit over folic acid regardless of MTHFR genotype -- avoid overselling the MTHFR-relevance angle.
Source: Hekmatdoost A et al. 2015, PLoS One 10(12):e0143569, PMID 26630680