Periconceptional folic acid taken during pregnancy may reduce the risk for autism spectrum disorders in children, according to new data from the American Society for Nutrition.
“For women who might get pregnant, following recommendations by taking at least 600 mcg folic acid before and very early in pregnancy could reduce risk for having a child with autism, in addition to improving other neurodevelopmental conditions shown in previous studies,” study researcher Rebecca J. Schmidt, PhD, told Healio.com.
Schmidt and colleagues surveyed mothers of 429 children with an autism spectrum disorder (ASD), 130 children with developmental delays and 278 children of typical development who were enrolled in the Childhood Autism Risks from Genetics and Environment (CHARGE), a population-based, case-control study conducted from 2003 to 2009.
The researchers quantified the mothers’ average daily folic acid intake on the basis of dose, brands and the frequency with which they consumed vitamins, supplements and breakfast cereals reported through structured telephone interviews. Children were assessed for cognitive function using the Mullen Scales of Early Learning, and the Vineland Adaptive Behavior Scales were used to evaluate adaptive function. Children of families recruited from the general population or with developmental delays were screened for ASD using the Social Communication Questionnaire. Blood was also collected from family members as part of the CHARGE study.
Multinomial logistic regression models were used to determine the association between categories of folic acid intake and case statuses of ASD or developmental delays compared with typical development.
The researchers found that the mean folic acid intake was significantly greater for mothers of children of typical development (779 ± 36.1 mcg) than for mothers of children with ASD (655 ± 28.7 mcg) in the first month of pregnancy (P,.01). A mean daily folic acid intake of at least 600 mcg — the recommended amount — during the first month of pregnancy was associated with reduced risk in ASD (OR=0.62; 95% CI, 0.42-0.92), and risk estimates decreased with increased amounts of folic acid (P-trend=.001). Fifty-four percent of mothers of children with ASD took the recommended amount on a daily basis vs. 69% of mothers of children of traditional development.
Results also showed that the “association between folic acid and reduced risk for ASD was observed primarily for mothers and children with MTHFR 677 C>T variant genotypes,” according to the researchers.
Because the reported intake of folic acid exceeded the recommended amount in all groups, Schmidt and colleagues said the recommended level is likely below what is needed to protect against neurodevelopmental conditions, especially for those with specific genetic variants.
In a press release, the researchers said, “Folic acid, the synthetic form of folate or vitamin B9, protects against deficits in early fetal brain development by facilitating DNA methylation reactions that can lead to epigenetic changes in gene expression; an ample supply of methyl donors like folic acid could be especially important in the period around conception when methylation marks are erased and re-established.”
Disclosure: The researchers report no relevant financial disclosures.