Folate

Folate (vitamin B9) is a water-soluble vitamin essential for one-carbon metabolism — the biochemical pathway underlying DNA synthesis, amino acid conversion, and epigenetic regulation. It is critically important during pregnancy for neural tube development. Approximately 40–60% of the population carries a variant of the MTHFR gene that reduces their ability to convert synthetic folic acid into the active form the body uses.

Folate is converted through a series of enzymatic steps into 5-methyltetrahydrofolate (5-MTHF), the active form that donates methyl groups to homocysteine (converting it to methionine) and supports thymidine synthesis (needed for DNA replication). Adequate folate is essential for rapidly dividing cells — making it critical for fetal development, red blood cell production, and gut mucosa maintenance.

400–800 mcg DFE/day (general); 600–1,000 mcg DFE/day (pregnancy). DFE = Dietary Folate Equivalents. If using methylfolate, 400–800 mcg/day of L-methylfolate (5-MTHF). Individuals with MTHFR variants should use methylfolate rather than synthetic folic acid.

L-Methylfolate (5-MTHF): The active, bioavailable form; bypasses MTHFR enzyme conversion; works for all genetic variants | Folic Acid: Synthetic form requiring enzymatic conversion; problematic for MTHFR variants; accumulation of unmetabolized folic acid is a concern at high doses | Folinic Acid: Natural intermediate form; better than folic acid, not as direct as methylfolate

UL for folic acid (synthetic) is 1,000 mcg/day — high doses can mask vitamin B12 deficiency symptoms. No established UL for natural folate or methylfolate. Caution in individuals with hormone-sensitive cancers (folate supports rapid cell division). This information is educational and is not medical advice.

SuppsBuddy strongly prefers L-methylfolate and penalizes products using synthetic folic acid as the sole form, given the prevalence of MTHFR variants. Paired B12 formulations receive a formulation quality bonus.