Folic acid, a form of vitamin B, is recommended to women who could become pregnant because it decreases the risk of newborns developing neural tube defects.
All women of childbearing age should consume 0.4 mg, 400 micrograms, of folic acid daily to prevent two common and serious birth defects, spina bifida and anencephaly, the US. Public Health Service and CDC recommends.
But a new study published in The Journal of the American Medical Association reveals that the supplement might have even more to offer.
"Mothers who took folic acid supplements in early pregnancy had a 40 percent reduced risk of having children with autistic disorder compared with mothers who did not take folic acid," said Dr. Pal Surén from the Norwegian Institute of Public health and the study's author.
About 85,000 Norwegian children born between 2002 and 2008 were studied as part of the research.
And unlike the fortified grains and cereals that are found in the U.S., Norway does not have a requirement for food products to be fortified with folic acid.
Therefore, researchers studied expectant mothers who were using folic acid supplements and tracked their progress beginning four weeks before and eight weeks into their pregnancy.
The findings showed that women who took the supplement were less likely to give birth to a child diagnosed with an autism spectrum disorder, ASD, as opposed to the women who did not consume folic acid.
When the study concluded, 270 children who were 3 to 10-years-old were diagnosed with ASD.
And more specifically, 114 were diagnosed with autistic disorder, 56 with Asperger syndrome and 100 with pervasive developmental disorder-not otherwise specified, PDD-NOS.
While the researchers admitted that they were unable to account for other factors that might have come into play that might have lowered the risk of autism for newborns, research shows that there is a protective effect associated with the supplement.
"Folic acid appears to have a protective effect, and given that it only occurs when you take it early, that tells you something," said Ian Lipkin, director of the Center for Infection & Immunity at Columbia University's Mailman School of Public Health.
"No one really knows precisely when autism comes about. The extent to which it comes early or later isn't entirely clear either. This suggests the protective effect of folic acid for autism is generated early. Although we don't understand the mechanisms, the recommendation is that people should start supplements when they want to get pregnant."
Lipkin authored a study about the relationship between folic acid and a reduced risk for autism using the same group of Norwegian children and found that mothers who took the supplement were less likely to have children who showed language delays by 3 years of age as opposed to childen of mothers who did not take folic acid.