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Vitamin B9 (Folate) — Frequently Asked Questions

This content is for informational purposes only and does not constitute medical advice. Consult your healthcare provider before starting any supplement. Full disclaimer

Frequently Asked Questions

What is the difference between folic acid and methylfolate?

Folic acid is the synthetic form found in supplements and fortified foods that must be converted through several enzymatic steps (including MTHFR) to become methylfolate (5-MTHF), the active form used in the body. An estimated 5-15% of the population has MTHFR polymorphisms (C677T, A1298C) that reduce this conversion by 30-70%. Methylfolate supplements bypass this entirely, providing the directly usable form.

When should I start taking folate for pregnancy?

Start folate supplementation at least 1-3 months before attempting conception, since neural tube closure occurs at 21-28 days post-conception — often before a woman knows she is pregnant. The CDC recommends all women of childbearing age consume 400 mcg daily regardless of pregnancy plans. During pregnancy, 600-800 mcg daily is recommended.

Should I take methylfolate instead of folic acid?

Methylfolate (5-MTHF) is a good choice if you have a known MTHFR polymorphism, are taking medications that affect folate metabolism, or want to avoid potential issues with unmetabolized folic acid. For most people without MTHFR variants, standard folic acid is effective and well-studied. Methylfolate costs more but eliminates any conversion concerns.

Full Vitamin B9 (Folate) Guide

References

  1. (). Prevention of neural tube defects: results of the Medical Research Council Vitamin Study. Lancet. DOI
  2. (). Lowering blood homocysteine with folic acid based supplements: meta-analysis of randomised trials. BMJ. DOI
  3. (). L-methylfolate as adjunctive therapy for SSRI-resistant major depression. American Journal of Psychiatry. DOI