Does Folic Acid Lower the Risk of Autism?

Autism risk is weakly linked to folic acid intake during pregnancy

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) Researchers report a link between autism and folic acid intake during pregnancy, but the link may be weak.

A recent report showed a small but increased risk of autism spectrum disorder (ASD) when folic acid intake during pregnancy was lower than the recommended levels. 

But experts say taking folic acid during pregnancy has many other known benefits. 

"Talk to your OB/GYN before taking any supplements."

Researchers, led by Rebecca Schmidt, PhD, at the University of California – Davis, investigated eating practices of mothers during pregnancy.  Mothers of 429 children with ASD, 130 with developmental delays and 278 who were typically developing were interviewed.

Mothers were asked to recall their eating habits and vitamin intake just before and during their pregnancy. The researchers then estimated the level of folic acid they were taking based on standard amounts of folic acid found in foods and vitamins.

They found that mothers of typically developing children consumed about 123 micrograms more folic acid during pregnancy than mothers of children with ASD. 

Additionally, they report that about 15 percent more mothers of typically developing children met the minimum recommendation of 600 micrograms per day.

This study is limited because it asked mothers to recall their eating habits, so the precise levels of folic acid intake are only estimated. Interpreting the 123 microgram difference between groups is complicated by the lack of accuracy in the measurement.

Michael Katz, MD, the interim medical director of the March of Dimes, noted that the differences in folic acid intake seen in this study were not big enough to be considered a clinical difference in folic acid intake. 

He noted that, “This article does not prove anything. It raises a question. A major study would be needed to prove it.” 

Dr. Katz did say that the March of Dimes recommends that mothers increase folic acid intake during pregnancy because it is known to prevent birth defects.

Folic acid is a B vitamin that is found in fortified foods, like breads and pastas, and in many prenatal and multivitamin supplements.

The report was published in May online ahead of print for the American Journal of Clinical Nutrition. The authors report no conflicts of interest.

Reviewed by: 
Review Date: 
June 11, 2012
Last Updated:
October 26, 2012