What is it? Overview Usage Side Effects and Warnings

What is Folate?

Folate, a B vitamin, plays a critical role in many biological processes. It participates in the crucial biological process known as methylation and plays an important role in cell division: without sufficient amounts of folate, cells cannot divide properly. Adequate folate intake can reduce the risk of heart disease and prevent serious birth defects, and it may lessen the risk of developing certain forms of cancer.

The use of folate supplements by pregnant women dramatically decreases the risk that their children will be born with a serious birth defect called neural tube defect. 1 This congenital problem consists of problems with the brain or spinal cord.

Folate supplements may also help prevent other types of birth defects, such as defects of the heart, palate, and urinary tract; conversely, drugs that impair folate action may increase risk of birth defects. (See Requirements/Sources for a list of the drugs involved.) An observational study suggests that folate supplements may reduce this risk in pregnant women taking such drugs. 2 Folate also lowers blood levels of homocysteine, which in turn has been hypothesized to reduce the risk of heart disease and other conditions. Studies conflict...

Safety Issues

Folate at nutritional doses is extremely safe. The only serious potential problem is that folate supplementation can mask the early symptoms of vitamin B 12 deficiency (a special type of anemia), potentially allowing more irreversible symptoms of nerve damage to develop. For this reason, when taking more than 400 mcg daily, it is important to get your B 12 level checked. See the article on Vitamin B 12 for more information.

Very high dosages of folate, greater than 5 mg (5,000 mcg) daily, can cause digestive upset. The maximum recommended dosage of folate for pregnant or nursing women is 1,000 mcg daily (800 mcg if under 19 years old). 3 Media reports that use of folate by pregnant women may increase their risk of breast cancer are based on a single study of...