Folic acid, a B vitamin that’s a key driver in cell growth, is perhaps best known for its ability to prevent birth defects in the spine and brain. The nutrient is found in fortified grains, fruits, leafy green vegetables, beans, and nuts. Supplements are also available.

Folic acid’s proven ability to prevent birth defects spurred the United States, in the late 1990s, to require manufacturers of grain products to fortify their foods with the vitamin, according to Harvard Health.

Researchers have studied folic acid over the years to measure its effectiveness against a slew of other conditions, including colon cancer, Alzheimer’s, and heart disease. However, for every study that claims benefit, another study finds none.

A controversy around folic acid benefits continues among medical professionals.

For example, The American Cancer Society reports that a study of women taking more than .4 milligrams—the federally recommended amount—experienced a decreased risk of colon cancer. However, after the government began requiring that certain foods be fortified, colon cancer rates increased, according to Harvard Health. A 2013 analysis of 13 clinical studies published in The Lancet, a leading medical journal, found folic acid made no difference on multiple types of cancer over five years.

Results are similarly mixed for Alzheimer’s disease. A study conducted by researchers in the Netherlands compared men and women taking folic acid to a group taking a placebo. The group taking the supplement outperformed the placebo group on tests that measured brain performance. However, a review of eight clinical trials found folic acid had no impact on cognitive functioning, leading one Mayo Clinic doctor to conclude that folic acid does not definitively ward against Alzheimer’s.

Researchers are similarly divided on folic acid’s impact on heart disease. The American Nutrition Association recommends taking folic acid to lower your risk of heart disease. Meanwhile, The American Heart Association does not recommend folic acid to reduce risk. Instead, it recommends eating a diet full of fruits, vegetables, and other nutritious foods.

Despite the folic acid controversy, researchers agree pregnant women benefit.

This one recommendation has stayed constant. The Centers for Disease Control and Prevention (CDC) recommends that women planning to become pregnant take .4 milligrams of folic acid daily to prevent major birth defects. Taking the supplement before pregnancy begins is key because spine and brain birth defects form very early in pregnancy, often before a woman knows that she’s pregnant.

Do you take a folic acid supplement to stay healthy?

Image by Bradley Stemke via Flickr


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