Introduction:

Folate and folic acid are forms of vitamin B9 used for deficiency and to prevent pregnancy complications. Many foods contain folate or have folic acid added. Since 1998, folic acid has been added to cold cereals, flour, breads, pasta, bakery items, cookies, and crackers, as required by federal law. Foods that are naturally high in folate include leafy vegetables, okra, asparagus, certain fruits, beans, yeast, mushrooms, animal liver and kidney, orange juice, and tomato juice. Folic acid is also available as a supplement, and is often used in combination with other B vitamins.

Uses:

High levels of homocysteine in the blood (hyperhomocysteinemia): This condition has been linked to heart disease and stroke. Taking folic acid by mouth lowers homocysteine levels in people with normal or high homocysteine levels and in people with kidney failure.

Toxicity caused by the drug methotrexate: Taking folic acid by mouth seems to reduce nausea and vomiting from methotrexate treatment.

Birth defects of the brain and spine (neural tube birth defects): Consuming folic acid 600-800 mcg by mouth daily during pregnancy reduces the risk of these birth defects. Folic acid can come from the diet or supplements. Some people who are at high risk should get 4000-5000 mcg daily.

Side Effects:

When taken by mouth: It is likely safe for most people to take folic acid in doses of no more than 1 mg daily. Doses higher than 1 mg daily may be unsafe. These doses might cause stomach upset, nausea, diarrhea, irritability, confusion, behavior changes, skin reactions, seizures, and other side effects. Another form of folic acid, L-5-methyltetrahydrofolate (L-5-MTHF), can also be found in supplements. This type of folic acid is possibly safe for most people in doses up to about 400 mcg daily. There is some concern that taking too much folic acid for a long time might cause serious side effects. Some research suggests that taking folic acid in doses of 0.8-1.2 mg daily might increase the risk for cancer or increase the risk of heart attack in people who have heart problems.