Folate (Vitamin B9)

At a glance

• Also calledVitamin B9, food folate, dietary folate

  Vitamin B9; food folate; dietary folate; naturally occurring folates; polyglutamyl folates; pteroylpolyglutamates. Historically vitamin M and vitamin Bc. On labels the amount is often given as dietary folate equivalents (DFE), a unit that exists precisely because the synthetic and the food forms are absorbed differently. Folate is the umbrella nutrient and the form found in food. Folic acid, the synthetic supplement and fortificant, and L-methylfolate, the circulating and separately marketed methylated form, are covered separately, because the evidence differs by form.

• Typical dose400 micrograms a day for adults

  400 micrograms per day for adults, expressed as dietary folate equivalents, as the recommended daily intake (Merrell and Patel, StatPearls, PMID 32119374). Note that the neural-tube-defect prevention evidence is about supplemental folic acid at a stated dose, not about food folate; see the folic-acid row for those figures.

• Upper limit1,000 micrograms a day; no separate limit for food folate

  1000 micrograms per day for adults. Intake below this level has not been shown to result in adverse health outcomes, and the National Toxicology Program found no definitive evidence of adverse effects at these levels (Merrell and Patel, StatPearls, PMID 32119374). That review names no separate limit for folate from food.

• Found inLeafy greens, liver and meat, eggs, milk

  Leafy green vegetables such as spinach, broccoli and lettuce. Liver and other meats. Eggs. Milk.