Folate

Also known as: methylfolate, 5-MTHF, folic acid, vitamin B9

Confidence

research strength

ASolid confidence74229 studies referenced

Latest evidence update: 2024-12-28

Strongest in Sample size (95). Held back by Recency (25).

Study quality (37%)

Study design (21%)

Risk of bias (16%)

Solid mix of RCTs with some methodological gaps.

Replication (26%)

Cross-study replication (21%)

Precision (5%)

Confirmed across many independent studies with significant findings.

Sample size (16%)

Tens of thousands of participants pooled across studies.

Consistency (11%)

Mostly aligned, with some divergence.

Recency (10%)

Mostly pre-2020 research; updates may be needed.

Effect by outcome

how big the change is

Effect-size tagged on 390 of 400 claims for this supplement. Our research updates daily; remaining claims are pending re-processing.

Directional evidence

Areas where research points to a consistent direction of effect. The strength of evidence is graded; the size of the effect is not quantified.

Mental health & wellbeing Cardiovascular health

Common dosage

400-800mcg daily

Description

Essential for DNA synthesis and methylation. Methylfolate is the active form — important for those with MTHFR variants.

Safety & interactions

Methylfolate preferred over folic acid, especially with MTHFR mutations.

Check interactions with other supplements→

What the research shows

↓

People with Alzheimer's disease have lower folate levels compared to those without the disease

moderate evidence1 study:Journal of human nutrition and dietetics : the official journal of the British Dietetic Association (2025)

↑

Eating salt fortified with multiple nutrients can help increase folate levels in the blood

emerging evidence1 study:Advances in nutrition (Bethesda, Md.) (2026)

Some links on this page may earn us a commission at no extra cost to you. This never influences our evidence grades or recommendations. Full disclosure

Order Folate

Recommended: 400-800mcg daily

Protocols featuring Folate

Iron & Energy RecoveryBBuilding confidence

Fertility & Prenatal OptimizationSHigh confidence

Questions about Folate

Who has been studied for Folate?

Are there known drug interactions with Folate?

Who should avoid Folate based on the safety notes?

Referenced studies (229)

ProtocolEngine provides general health information based on published research. This is not medical advice. Consult a healthcare professional before starting any supplement or health protocol.