Calcium L-5-Methyltetrahydrofolate (Metafolin, brand)
Calcium L-5-Methyltetrahydrofolate (Metafolin, brand) is a tier 1 form of Folate (Vitamin B9), used in 506 on-market products and providing 92.3% elemental folate (vitamin b9) by weight.
506
on-market products
tier 1
quality tier
92.3%
elemental fraction
Basis: free-acid L-5-MTHF MW 459.46 / calcium salt MW 497.53 (confirmed PubChem formula)
Why this tier: Same active-form rationale as L-5-MTHF -- the calcium salt is simply the stabilized, tabletable version of the same active molecule (not separately tested head-to-head).
Source: Hekmatdoost A et al. 2015, PMID 26630680 (parent vitamer's tier rationale)