Maternal Dietary Factors and the Risk of Autism Spectrum Disorders: A Systematic Review of Existing Evidence.
Prenatal multivitamin, folic acid, and vitamin D are linked to lower autism odds, yet kids with autism still end up low on the same nutrients.
01Research in Context
What this study did
The authors searched every major database for papers on moms’ diets and later autism diagnosis. They kept 36 studies that tracked vitamins, minerals, or fish oil taken while pregnant. All papers compared moms of kids with autism to moms of typically developing kids.
No kids were treated; the team simply counted and pooled what earlier researchers had already published.
What they found
Moms who took prenatal multivitamins, folic acid, or extra vitamin D had lower odds of having a child with autism. Results were not the same across every paper; some studies showed no link.
Other nutrients like iron, omega-3, or vitamin B-12 showed no clear pattern.
How this fits with other research
Whitehouse et al. (2014) is inside this review. Their own data showed a 74 % drop in autistic-like traits when moms took vitamins at least weekly. The review’s broad picture agrees with their single-study finding.
Pu et al. (2013) looked at a gene, not diet. They found that moms who carry a slow-folate-processing gene had slightly higher autism odds. The review and the gene study fit together: extra folic acid may help exactly when the gene slows folate use.
Miltenberger et al. (2013) and Sánchez-Gómez et al. (2023) flip the timeline. They show that after birth, kids with autism often eat poorly and lack vitamin D. The review and these child studies create one story: low vitamin D can enter with the mom and stay with the child.
Why it matters
You can’t change genes, but you can ask about prenatal vitamins during intake. If the child already has autism, check both past maternal use and current child diet. Simple screens and low-cost supplements may close a nutrition gap that starts before birth and lingers in the lunchbox.
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02At a glance
03Original abstract
Prenatal maternal diet is a critical factor in offspring neurodevelopment. Emerging evidence suggests that prenatal diet may also play a role in the etiology autism spectrum disorder (ASD). This review summarizes studies published in English that examined prenatal nutrients or maternal diet in association with ASD from PubMed as of July 2020. Thiry-six studies from nine countries were included in this systematic review; these focused on multivitamin (n = 5), prenatal vitamin (n = 3), folic acid (FA; n = 14), Vitamin D (n = 11), polyunsaturated fatty acid or fish/supplement intake (n = 7), iron (n = 3), Vitamin B12 (n = 1), calcium (n = 1), magnesium (n = 1), and broad maternal dietary habits (n = 3). Overall, higher or moderate intake of prenatal/multivitamin, FA, and Vitamin D was associated with reductions in odds of ASD, though results have not been uniform and there is a need to clarify differences in findings based on biomarkers versus reported intake. Evidence was inconclusive or insufficient for other nutrients. Differences in the timing and measurement of these dietary factors, as well as potential residual confounding, may contribute to existing discrepancies. Key areas for future research to better understand the role of maternal diet in ASD include the need to address potential critical windows, examine the combined effect of multiple nutrients, and consider interactions with genetic or environmental factors. LAY SUMMARY: Maternal diet during pregnancy is important for child neurodevelopment. We reviewed 36 studies examining maternal diet and autism spectrum disorder (ASD) and found that prenatal vitamin/multivitamin use and adequate intake of folic acid and Vitamin D were each associated with lower likelihood of having a child with ASD. Future studies on these and other dietary factors are needed to better understand the role of maternal diet in the development of ASD. Autism Res 2020, 13: 1634-1658. © 2020 International Society for Autism Research and Wiley Periodicals LLC.
Autism research : official journal of the International Society for Autism Research, 2020 · doi:10.1093/cdn/nzz039.OR06-02-19