What it does in the body
- Thymidylate synthesis (dTMP — essential for DNA replication)
- Purine synthesis (building blocks of DNA and RNA)
- Homocysteine remethylation to methionine (via methionine synthase, B12-dependent)
- S-adenosylmethionine (SAM) generation for methylation reactions
- Neural tube closure in embryonic development
How much you need (Daily Value)
| Group | Recommended | Source |
|---|---|---|
| Adult male | 400 mcg DFE | NIH/IOM |
| Adult female | 400 mcg DFE | NIH/IOM |
| Pregnancy | 600 mcg DFE (+ 400 mcg folic acid supplement preconception) | WHO/IOM |
| Children | 150-300 mcg DFE (ages 1-13) | WHO |
| Older adults | 400 mcg DFE | NIH |
Richest food sources
| Food | Amount | Where |
|---|---|---|
| Beef liver | 290 mcg per 100g | global |
| Lentils (cooked) | 181 mcg per 100g | South Asia/Middle East |
| Spinach (cooked) | 146 mcg per 100g | global |
| Black-eyed peas (cooked) | 210 mcg per 100g | Africa/Americas |
| Asparagus (cooked) | 149 mcg per 100g | Europe/Americas |
| Edamame | 303 mcg per 100g | East Asia |
| Fortified enriched flour | 140-150 mcg per 100g | Americas (mandatory since 1998) |
| Brussels sprouts (cooked) | 78 mcg per 100g | Europe |
In our food database, per 100 g
Highest among our free foods — open the Food Explorer to compare.
If you don't get enough
Mild: Elevated homocysteine, fatigue, irritability, poor concentration
Moderate: Megaloblastic anemia (macrocytic, hypersegmented neutrophils), glossitis, diarrhea
Severe: Neural tube defects (spina bifida, anencephaly) in developing embryos, pancytopenia, increased cardiovascular risk from hyperhomocysteinemia
Time to onset: Serum folate drops within 3 weeks; megaloblastic changes in 4-5 months. NTDs occur within the first 28 days of gestation
Too much
Upper limit: 1000 mcg DFE/day from folic acid (supplements/fortification) — not applicable to food folate
Primary risk is masking B12 deficiency (corrects anemia but not neurological damage). Very high doses may promote growth of pre-existing neoplasms (controversial). May reduce efficacy of antifolate drugs (methotrexate, trimethoprim).
How well you absorb it
Food folate: ~50% bioavailable; folic acid (supplement, empty stomach): ~100%; folic acid (with food): ~85%. 1 mcg DFE = 1 mcg food folate = 0.6 mcg folic acid (supplement with food)
Helped by: Vitamin C (stabilizes reduced folates), Vitamin B12 (methionine synthase regenerates THF from 5-MTHF)
Hindered by: Alcohol (impairs absorption and increases urinary excretion), Methotrexate (dihydrofolate reductase inhibitor), Phenytoin, sulfasalazine, trimethoprim, MTHFR C677T polymorphism (reduced enzyme activity)
Cooking & storage
Folate is very heat-sensitive and water-soluble; 50-90% can be lost during boiling. Steaming and microwaving preserve more folate. Canned vegetables retain less folate than fresh or frozen. Ascorbic acid in cooking water helps stabilize folate.
Nutrisize Health totals every nutrient from what you actually eat, against targets set for your age and sex, and flags what's short — across 4,995 foods, on your device.
