The Link Between Folic Acid and Autism

If you are a woman of child-bearing age, be sure to ask your doctor about taking folic acid supplements. A new study reported on shows that women who take the supplements before conceiving, as well as early in pregnancy, may reduce their risk of having a child with autism.

Researchers focused on 85,000 babies born between 2002 and 2008 for a period of three to ten years. They followed women who'd taken a folic acid supplement for four weeks before becoming pregnant until eight weeks after the pregnancy began. The researchers' goal was to learn if the mother's use of these supplements had any bearing on whether the child developed autism.

Some 270 children had been diagnosed with autism spectrum disorder by the end of the follow-up period (114 with autistic disorder, 56 with Asperger Syndrome, and 100 with PDD-NOS, or pervasive developmental disorder—not otherwise specified.) Researchers learned that the mothers who'd taken folic acid supplements had a 40 percent reduced risk of having a child with autistic disorder than moms who had not taken the supplement. The research did not find any reduction in the risk factor for either PDD-NOS or Asperger syndrome.

"This new study provides further support to the importance of women taking folate supplements before becoming pregnant," says Andrew Adesman, MD, chief of Developmental & Behavioral Pediatrics at the Steven & Alexandra Cohen Children's Medical Center of New York in Hyde Park, NY.

The supplements appear to not only reduce the risk of spina bifida and other neural tube defects, but the risk of autism in young children, he said.

"Given the profound emotional, financial, and societal costs associated with having a child with autism, this study provides further proof of Ben Franklin's adage that 'an ounce of prevention is worth a pound of cure,'" Adesman says.

While folic acid supplements taken early in pregnancy don't eliminate the risk for autism, it's worth taking them just to cut your risk, he says. "The nice thing about this finding is that it suggests something that is very simple, inexpensive, and easy to do," Adesman says. "And the supplements may be associated with better long-term child development."

Folate, the naturally occurring form of the B vitamin called folic acid, is found in green leafy vegetables, peas, lentils, yeast, and liver. Cereal, bread, and flour are fortified with folic acid, although, as Adesman points out, dietary sources of folic acid are not typically sufficient.

How much folic acid should women be taking in a supplement? The March of Dimes says all women of child-bearing age should take 400 micrograms of folic acid daily in the form of a multivitamin. And once they become pregnant, women should keep taking 400 mcg of folic acid on a daily basis.

Andrew Adesman, MD, reviewed this article.


Winters, Catherine. 10 March 2013. "Folic acid in pregnancy may reduce autism risk." HealthNewsDaily.