Preconceptional and prenatal supplementary folic acid and multivitamin intake and autism spectrum disorders.
Prenatal folic acid does not lower autism odds, though a smaller high-risk group may still benefit.
01Research in Context
What this study did
Virk et al. (2016) looked at moms who took folic acid or multivitamins. They checked records from four weeks before pregnancy through eight weeks after. Then they counted how many kids later got an autism diagnosis.
The study used birth and health registries. It compared moms who took vitamins with moms who did not.
What they found
The team found no drop in autism risk for kids whose moms took the pills. Folic acid and multivitamins did not protect against ASD in this large group.
How this fits with other research
Zhao et al. (2024) seems to disagree. They saw that toddlers had far higher autism odds when moms skipped folic acid. The key difference is the group studied. Jasveer looked at all moms. Qian only looked at moms with unplanned pregnancies.
Freeman et al. (2015) and Syriopoulou-Delli et al. (2012) line up with Jasveer. Both found no ASD link after moms smoked while pregnant. Like vitamins, smoking showed no clear harm once other facts were counted.
Hollowood et al. (2018) took a third path. A blood test sorted moms into high- or low-risk groups by folate-pathway markers. That study did not test pills; it only predicted risk.
Why it matters
You can reassure families. Taking prenatal vitamins is still healthy for mom and baby, but it will not prevent autism. Focus your teaching on evidence-based strategies like early screening and behavioral intervention instead of pill promises.
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02At a glance
03Original abstract
OBJECTIVE: To evaluate whether early folic acid supplementation during pregnancy prevents diagnosis of autism spectrum disorders in offspring. METHODS: Information on autism spectrum disorder diagnosis was obtained from the National Hospital Register and the Central Psychiatric Register. We estimated risk ratios for autism spectrum disorders for children whose mothers took folate or multivitamin supplements from 4 weeks prior from the last menstrual period through to 8 weeks after the last menstrual period (-4 to 8 weeks) by three 4-week periods. RESULTS: We did not find an association between early folate or multivitamin intake for autism spectrum disorder (folic acid-adjusted risk ratio: 1.06, 95% confidence interval: 0.82-1.36; multivitamin-adjusted risk ratio: 1.00, 95% confidence interval: 0.82-1.22), autistic disorder (folic acid-adjusted risk ratio: 1.18, 95% confidence interval: 0.76-1.84; multivitamin-adjusted risk ratio: 1.22, 95% confidence interval: 0.87-1.69), Asperger's syndrome (folic acid-adjusted risk ratio: 0.85, 95% confidence interval: 0.46-1.53; multivitamin-adjusted risk ratio: 0.95, 95% confidence interval: 0.62-1.46), or pervasive developmental disorder-not otherwise specified (folic acid-adjusted risk ratio: 1.07, 95% confidence interval: 0.75-1.54; multivitamin: adjusted risk ratio: 0.87, 95% confidence interval: 0.65-1.17) compared with women reporting no supplement use in the same period. CONCLUSION: We did not find any evidence to corroborate previous reports of a reduced risk for autism spectrum disorders in offspring of women using folic acid supplements in early pregnancy.
Autism : the international journal of research and practice, 2016 · doi:10.1177/1362361315604076