Folate
Also known as: folic acid, vitamin B9, 5-methyltetrahydrofolate, 5-MTHF, methylfolate, L-methylfolate, pteroylglutamic acid
Effective Dosage
No established universal dose from provided studies; prenatal/fortification doses ranged from 36–99 ppm in salt or standard prenatal multivitamin amounts
What the Science Says
Folate is an essential B vitamin (B9) that the body needs for DNA synthesis, cell division, and amino acid metabolism. The strongest evidence from the provided studies supports its role in improving folate status in women of reproductive age and reducing the risk of neural tube defects (NTDs) in developing fetuses — folic acid fortification of salt significantly raised red blood cell folate levels in Ethiopian women. Severe folate deficiency can cause serious blood disorders, including a rare but reversible condition that mimics a dangerous clotting disease (pseudo-TMA), which resolved completely with folate supplementation.
What It Doesn't Do
Won't replace a balanced diet on its own. No evidence from these studies that it boosts energy, improves athletic performance, or supports weight loss. The 'methylfolate is always better than folic acid' claim is not fully proven — a small feasibility trial found 5-MTHF and folic acid both workable, but couldn't confirm one is clinically superior. Folate supplements won't fix anemia caused by iron deficiency or other unrelated causes.
Evidence-Based Benefits
Folate is essential for DNA synthesis, repair, and methylation, making it crucial for cell division and growth. It is particularly important during periods of rapid growth, such as during pregnancy and fetal development, and has been shown to reduce the risk of neural tube defects in newborns.
Strong EvidenceEffective at: 400-800 mcg daily
Source: auto-research
Absorption & Bioavailability
Moderate to Good — folic acid (synthetic form) is well absorbed but can accumulate as unmetabolized folic acid in blood, especially at high doses. 5-MTHF (active form) avoids this issue but showed formulation instability in one study. Plant-based diets rich in fortified foods raised plasma folate significantly in an 8-week RCT.
Red Flags to Watch For
- Unmetabolized folic acid can accumulate in the blood when taking high-dose folic acid supplements — the active form (5-MTHF) may be preferable for some people, but formulation stability is a concern
- Folate deficiency can mimic serious blood disorders (pseudo-TMA/HUS) — severe symptoms like anemia, low platelets, and kidney injury need urgent medical evaluation, not just self-supplementation
- People with MTHFR gene variants may process folic acid less efficiently, but the clinical significance of switching supplement forms is not yet proven in large trials
- Folate supplements can mask vitamin B12 deficiency — always check B12 status alongside folate, especially in vegetarians and older adults
Products Containing Folate
See how Folate is used in these analyzed products:
Research Sources
- PubMed
- NIH DSLD
This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-04-06