Folate
Content by: OpenSupplement Editorial Team | Medical review: pending | Last updated: April 13, 2026
TL;DR
Vitamin B9, critical for DNA repair and lowering homocysteine
Moderate evidence for cognitive decline and heart health
Methylfolate (5-MTHF) is the preferred bioactive form
Essential for preventing neural tube defects in pregnancy
Excellent safety; may mask B12 deficiency
Cost: ~$5-10/month
Best for: Cognitive support, high homocysteine, pregnancy
What it is
Folate is the natural form of Vitamin B9 found in leafy greens (foliage). It is the 'master regulator' of methylation, a process the body uses to repair DNA and control neurotransmitters.
Many people have a genetic variation (MTHFR) that makes it difficult to convert synthetic 'folic acid' into the active form the body can use. Therefore, high-quality supplements use Methylfolate, which bypasses this bottleneck and goes straight to work in the brain and blood.
What the research says
Folate is a brain-saver. The FACIT Trial. This major study showed that folate supplementation significantly improved memory and information processing speed in older adults with high homocysteine. Atrophy. Like B12, folate helps prevent the brain shrinkage associated with aging. Depression. It is also a proven 'augmenter' for antidepressants, helping them work better by boosting serotonin production. [1][3]
Folate protects the arteries by lowering homocysteine. Stroke Risk. A massive trial in China (the CSPPT study) found that folate supplementation reduced the risk of stroke by 21% in hypertensive adults. It helps the endothelium (blood vessel lining) function better, which is key for heart health. [2]
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Folate on Amazon
Safety
Very safe. The main risk is that high folate can 'mask' a Vitamin B12 deficiency by fixing the anemia while the nerve damage continues. Always take Folate with B12.
Interactions
- Methotrexate: Folate can reduce the effectiveness of this chemotherapy/rheumatoid arthritis drug.
- Anticonvulsants: May lower blood levels of drugs like Phenytoin.
Dosing
Standard Dose: 400-800 mcg daily. Form: MUST be 5-MTHF (Methylfolate), not 'folic acid.'
Cost
Cheap. $5-10 per month.
The bottom line
Folate is a 'must-have' for brain and heart longevity, especially if your homocysteine is elevated. Just make sure you're taking the methylated form.
References
- Durga J, van Boxtel MP, Schouten EG, et al. Effect of 3-year folic acid supplementation on cognitive function in older adults in the FACIT trial: a randomised, double blind, controlled trial. Lancet. 2007;369(9557):208-216.
- Clarke R, Halsey J, Lewington S, et al. Effects of lowering homocysteine levels with B vitamins on cardiovascular disease, cancer, and cause-specific mortality: Meta-analysis of 8 randomized trials involving 37 485 individuals. Arch Intern Med. 2010;170(18):1622-1631.
- NIH Office of Dietary Supplements. Folate Fact Sheet for Health Professionals.
Sources for this page include published meta-analyses, systematic reviews, and NIH dietary supplement fact sheets. All claims reflect the evidence as of early 2026.
This is not medical advice. Consult your healthcare provider before starting any supplement, especially if you take medications.