Overview
One-carbon donor essential for DNA synthesis and neural tube development.
- Leafy greens
- Legumes
- Liver
- Folic acid (synthetic)
- 5-MTHF (active)
- Folinic acid
Forms & variants of Folate (Vitamin B9)
Different chemical forms of Folate (Vitamin B9) behave differently. Browse each form's mechanism, bioavailability, and best-use context.
Mechanism of action
Provides methyl groups for DNA synthesis, homocysteine remethylation, and monoamine synthesis.
- · One-carbon metabolism
- · Methylation cycle
Effects on the body
Organ system effects
Adjunct in depression, especially with MTHFR variants.
Evidence-based benefits
Prevents neural tube defects (preconception)
Strong evidenceAugments SSRIs in depression (L-methylfolate)
Moderate evidencePotential side effects
- · Masks B12 deficiency
Drug interactions
Supplement interactions
- A high-quality multivitaminCovers micronutrient cofactors that support most supplement pathways.
- Omega-3 (EPA/DHA)Foundational anti-inflammatory support that complements most regimens.
No specific avoidances listed.
Dosing & bioavailability
Where to buy
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Third-party testedIndependently verified Folate (Vitamin B9) — look for USP, NSF, or Informed Sport seals on the label for purity and dose accuracy.Folate (Vitamin B9) third party tested NSF
CapsulesPre-measured Folate (Vitamin B9) capsules — easiest for travel and consistent daily dosing without scoops or scales.Folate (Vitamin B9) capsules
PowderBulk unflavored Folate (Vitamin B9) powder — best cost-per-gram and flexible dosing for stacking or mixing into drinks.Folate (Vitamin B9) powder unflavored
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Folate (Vitamin B9): pharmacology, clinical evidence, and safety — narrative review
Examine.com Research Team
Curated narrative review of human and preclinical evidence for Folate (Vitamin B9), including mechanism, typical dosing, and safety considerations.
Best-supported outcome: Prevents neural tube defects (preconception) (evidence: strong). Additional outcomes and limitations summarized in the full profile.
PubMed: Folate (Vitamin B9) — Prevents neural tube defects
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PubMed: Folate (Vitamin B9) — Augments SSRIs in depression
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PubMed: Folate (Vitamin B9) — randomized controlled trial
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PubMed: Folate (Vitamin B9) — meta-analysis
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PubMed: Folate (Vitamin B9) — pharmacokinetics
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PubMed: Folate (Vitamin B9) — safety adverse events
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PubMed: Folate (Vitamin B9) — dose response
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Google Scholar: Folate (Vitamin B9) — clinical evidence
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Cross-database citation index for Folate (Vitamin B9) as it relates to "clinical evidence".
Includes preprints, theses, and journal articles. Useful for tracking citation counts and follow-on work.