Folic Acid During Pregnancy May Reduce Autism Risk

February 13, 2013

Large study in Norway finds early timing of supplements is critical

The Mailman School of Public Health reports that prenatal folic acid supplements appear to reduce the risk for autistic spectrum disorders.

According to a study in the Journal of the American Medical Association (JAMA), women who took folic acid supplements in early pregnancy had a 40 percent lower risk of having children with autistic disorder (the most severe form of autism spectrum disorders) than those who did not take folic acid. The reduced risk was seen in those who took folic acid from 4 weeks before to 8 weeks after the start of pregnancy.

A total of 85,176 Norwegian babies—born from 2002–2008—and their parents participated in the Norwegian Mother and Child Cohort Study (MoBa) and its sub-study of autism, the Autism Birth Cohort (ABC) Study. Prenatal dietary habits were recorded and families were regularly surveyed for 3–10 years, to measure the development of autism spectrum disorders. The researchers identified 270 cases of autism spectrum disorders in the study population: 114 cases of autistic disorder, 56 cases of Asperger syndrome, and 100 cases of pervasive developmental disorder not otherwise specified (PDD-NOS).

The researchers found no reduction in risk for PDD-NOS, and the number of children studied was too low to determine any reduction in risk for Asperger syndrome.

We examined the rate of autism spectrum disorders in children born to mothers who did or did not take folic acid during pregnancy. There was a dramatic reduction in the risk of autistic disorder in children born to mothers who took folic acid supplements,” says Pål Surén, first author and epidemiologist at the Norwegian Institute of Public Health (NIPH).

The researchers also looked at the influence of other dietary supplements on the risk of autistic disorder. They found no association between the mother’s use of fish oil (cod liver oil and omega-3 fatty acids) or other vitamins and minerals in early pregnancy and the risk of autistic disorder.

Read more from The Mailman School of Public Health.


Asperger syndrome, Autism, Autism spectrum, Columbia Mailman School of Public Health, Folic acid, Journal of the American Medical Association, Norwegian Institute of Public Health, PDD-NOS, top-story