Folic acid is a type of B vitamin. It is the man-made (synthetic) form of folate that is found in supplements and added to fortified foods.
Folic acid is water-soluble. Water-soluble vitamins dissolve in water. Leftover amounts of the vitamin leave the body through the urine. That means your body does not store folic acid and you need a continuous supply of the vitamin in the foods you eat.
Folate helps tissues grow and cells work. Taking the right amount of folic acid before and during pregnancy helps prevent certain birth defects, including spina bifida. Folate also helps prevent anemia.
Folate works along with vitamin B12 and vitamin C to help the body break down, use, and create new proteins. The vitamin helps form red blood cells and produce DNA, the building block of the human body, which carries genetic information.
Folic acid supplements may also be used to treat folic acid deficiency, certain menstrual problems, and leg ulcers.
Folate occurs naturally in the following foods:
Dark green leafy vegetables
Dried beans and peas (legumes)
Citrus fruits and juices
Fortified means that vitamins have been added to the food. Many foods are now fortified with folic acid, including enriched breads, cereals, flours, cornmeals, pastas, rice, and other grain products.
Too much folic acid usually doesn't cause harm, because the vitamin is regularly removed from the body through urine.
The best way to get the daily requirement of essential vitamins is to eat a wide variety of foods. Most people in the United States get enough folic acid in their diet because it is plentiful in the food supply.
There is good evidence that folic acid can help reduce the risk of certain birth defects (spina bifida and anencephaly). Women who are pregnant or planning to become pregnant should take at least 400 micrograms (mcg) of folic acid every day. Pregnant women need even higher levels of folic acid. Ask your health care provider which amount is best for you.
The Recommended Dietary Allowance (RDA) for vitamins reflects how much of each vitamin most people should get each day.
The RDA for vitamins may be used as goals for each person.
How much of each vitamin you need depends on your age and gender. Other factors, such as pregnancy and illnesses, are also important.
The Food and Nutrition Board of the Institute of Medicine Recommended Intakes for Individuals - Daily Reference Intakes (DRIs) for folate:
0 - 6 months: 65 mcg/day
7 - 12 months: 80 mcg/day
1 - 3 years: 150 mcg/day
4 - 8 years: 200 mcg/day
9 - 13 years: 300 mcg/day
Adolescents and Adults
Males age 14 and older: 400 mcg/day
Females age 14 - 50: 400 mcg/day plus 400 mcg/day from supplements or fortified foods
Females age 50 and over: 400 mcg/day
Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, PantothenicAcid, Biotin, and Choline. National Academy Press, Washington, DC, 1998.
Escott-Stump S, ed. Nutrition and Diagnosis-Related Care. 6th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2008.
Sarubin Fragaakis A, Thomson C. The Health Professional's Guide to Popular Dietary Supplements. 3rd ed. Chicago, IL: American Dietetic Association; 2007.
Alison Evert, MS, RD, CDE, Nutritionist, University of Washington Medical Center Diabetes Care Center, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.