Folate (Folic Acid)

Reviewed by Sabrina Felson, MD on August 05, 2022
photo of woman holding supplement bottle

Folate, formerly known as folacin, is the generic term for both naturally occurring food folate and folic acid, the fully oxidized monoglutamate form of the vitamin that is used in dietary supplements and fortified foods. It is a B vitamin that's important for cell growth and metabolism. Studies show that many people in the U.S. don't get enough folic acid.

Don't be confused by the terms folate and folic acid. They have the same effects. Folate is the natural version found in foods. Folic acid is the man-made version in supplements and added to foods.

Folic acid supplements are standard for pregnant women and women who plan to become pregnant. Folic acid reduces the risk for birth defects of a baby’s brain and spine -- spina bifida and anencephaly -- by 50% or more. Folic acid may also lower the risk of preeclampsia and early labor. Many doctors recommend that women of childbearing age take either a multivitamin or a folic acid supplement. Folic acid can protect against birth defects that may form before a woman knows they are pregnant.

Folic acid is used to treat deficiencies, which can cause certain types of anemia and other problems. Folate deficiencies are more common in people who have digestive problems, kidney or liver disease, or who abuse alcohol. Folic acid is also used to reduce the toxicity of the drug methotrexate in psoriasis and rheumatoid arthritis patients.

Folic acid supplements have been studied as treatments for many other conditions. So far, the results of these studies have been inconclusive.

The recommended dietary allowance (RDA) includes the folate you get from both the food you eat and any supplements you take.


Folate (Folic Acid)
Recommended Dietary Allowance (RDA)

For children under 1, only an adequate intake (AI) is available
0-6 months
65 micrograms/day
Adequate Intake (AI)
7-12 months
80 micrograms/day
Adequate Intake (AI)
1-3 years
150 micrograms/day
4-8 years
200 micrograms/day
9-13 years
300 micrograms/day
14 years and up
400 micrograms/day
Pregnant women
600 micrograms/day
500 micrograms/day

The tolerable upper intake levels (UL) of a supplement are the highest amount that most people can take safely. Higher doses might be used to treat folate deficiencies. But don't take more unless a doctor says so.

(Children & Adults)
Folate (Folic Acid)
Tolerable Upper Intake Levels (UL)
1-3 years300 micrograms/day
4-8 years400 micrograms/day
9-13 years600 micrograms/day
14-18 years800 micrograms/day
19 years and up1,000 micrograms/day


Good sources of folate are:

  • Leafy green vegetables, like spinach, broccoli, and lettuce
  • Beans, peas, and lentils
  • Fruits like lemons, bananas, and melons
  • Fortified and enriched products, like some breads, juices, and cereals


  • Side effects. Folic acid is generally regarded as safe. Side effects are rare. High doses of folic acid can cause nausea, bloating, gas, and insomnia.
  • Interactions. High doses of folic acid can block the effects of some seizure medicines. If you take any regular medicines, ask how they will affect your intake of folic acid. 
  • Risks. Folic acid supplementation can sometimes mask the neurologic symptoms of serious and dangerous deficiencies of vitamin B12.

Show Sources


Longe, J., ed. The Gale Encyclopedia of Alternative Medicine, second edition, 2004.

Natural Standard Patient Monograph: "Folic acid."

Office of Dietary Supplements web site: "Folic acid."

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