It’s long been understood that folic acid supplementation before and during pregnancy reduces the risk of spina bifida and other neural tube defects in children. But can it also prevent autism?
Last year, a Norwegian group of researchers asked this very question.
The researchers followed 85,176 children born to mothers who took folic acid supplements beginning 4 weeks prior to conception through the 8th week of pregnancy. Although some of these children did develop autism, the incidence rate of autism spectrum disorders (ASD) in this group was half that of the general population.1 This study suggests that folic acid supplementation before and during pregnancy may reduce the risk of autism in children.
Another study of 38,954 children in Norway found that children whose mothers supplemented with folic acid had a lower risk of severe language delay by the age of three.2
And yet another study conducted in California demonstrated that women who took folic acid and prenatal vitamins for the 3 months prior before they became pregnant and during the first month of pregnancy were less likely to have a child with autism.3,4
Thankfully, most prenatal supplements sold in the United States today contain folic acid, so there’s probably no need to pick up a separate folic acid supplement if you’re already taking a good quality prenatal.
 Suren P, et al. Association between maternal use of folic acid supplements and risk of autism spectrum disorders in children. JAMA 13 Feb 2013;309(6):570–577.
 Roth C, Magnus P, Scjolberg S, et al. Folic acid supplements in pregnancy and severe language delay in children. JAMA. 2011;306(14):1566-1573.
 Schmidt RJ, Hansen RL, Hartiala J, et al. Prenatal vitamins, one-carbon metabolism gene variants, and risk for autism. Epidemiology. 2011;22(4):476-485.
 Schmidt RJ, Tancredi DJ, Ozonoff S, et al. Maternal periconceptional folic acid intake and risk of au- tism spectrum disorders and developmental delay in the CHARGE (Childhood Autism Risks from Genet- ics and Environment) case-control study. Am J Clin Nutr. 2012;96(1):80-89.