Vitamins
Folate (Methylfolate / Vitamin B9)
Also known as: Folic acid · Methyltetrahydrofolate · 5-MTHF · Vitamin B9
Critical for DNA synthesis and cell division. Folic acid (synthetic) must be converted to the active form — those with MTHFR gene variants should use methylfolate directly.
Effective Dose
400–800mcg / day
per clinical evidence
Evidence Level
Strong
Vitamins
Mechanism
One-carbon metabolism, DNA synthesis, homocysteine remethylation
primary action
Best For
Pregnancy
Cardiovascular health, MTHFR variants, Cell division
This profile is for informational purposes only and does not constitute medical advice. Consult a qualified healthcare professional before starting any supplementation, especially if you have pre-existing conditions or take medications.
What Is Folate (Methylfolate / Vitamin B9)?
Folate (the natural form) and folic acid (synthetic supplement form) are both forms of vitamin B9. They are essential for one-carbon metabolism — the transfer of single-carbon groups in DNA synthesis, repair, and methylation reactions. Neural tube defects from folate deficiency in early pregnancy are among the most preventable birth defects.
How It Works: The Science
Folate is reduced to tetrahydrofolate (THF) and carries one-carbon units for purine and thymidylate synthesis (DNA building blocks) and for remethylation of homocysteine to methionine (with B12). The MTHFR C677T polymorphism (present in ~10–15% of people) impairs folic acid conversion — methylfolate (5-MTHF) bypasses this step.
Primary Mechanism
One-carbon metabolism, DNA synthesis, homocysteine remethylation
Evidence-Based Benefits
Dosage Guide
Effective Dose
400–800mcg / day
400mcg/day for general population. 800mcg/day for those trying to conceive. Use 5-MTHF (methylfolate) if you have the MTHFR C677T or A1298C variant — folic acid may partially accumulate unmetabolised in these individuals.
Safety Profile & Side Effects
Very safe. Folic acid supplementation can mask B12 deficiency — always pair with B12. Tolerable upper limit: 1000mcg/day (folic acid). No upper limit established for methylfolate.
Who Should (and Shouldn't) Take It
All women of reproductive age (mandatory peri-conception), those with MTHFR variants, anyone with elevated homocysteine, and vegans (low dietary folate from fortified foods may be insufficient).
Frequently Asked Questions
Related Ingredients
Medical Disclaimer
Ingredient profiles are for informational purposes only and do not constitute medical advice. Consult a qualified healthcare professional before starting any supplementation, especially if you have pre-existing conditions or take medications. Full disclaimer →