Background: There is growing interest in linking vitamin D deficiency with autism spectrum disorders (ASDs). The association between vitamin D deficiency during gestation, a critical period in neurodevelopment, and ASD is not well understood. Aims: To determine the association between gestational vitamin D status and ASD. Method: Based on a birth cohort (n=4334), we examined the association between 25-hydroxyvitamin D (25OHD), assessed from both maternal mid-gestation sera and neonatal sera, and ASD (defined by clinical records; n=68 cases). Results: Individuals in the 25OHD-deficient group at mid-gestation had more than twofold increased risk of ASD (odds ratio (OR)=2.42, 95% confidence interval (CI) 1.09 to 5.07, P=0.03) compared with the sufficient group. The findings persisted in analyses including children of European ethnicity only. Conclusions: Mid-gestational vitamin D deficiency was associated with an increased risk of ASD. Because gestational vitamin D deficiency is readily preventable with safe, inexpensive and readily available supplementation, this risk factor warrants closer scrutiny.,
British Journal of Psychiatry

Vinkhuyzen, A. A., Eyles, D. W., Burne, T. H., Blanken, L., Kruithof, C., Verhulst, F., … Mcgrath, J. J. (2017). Gestational vitamin D deficiency and autism spectrum disorder. British Journal of Psychiatry, 3, 85–90. doi:10.1192/bjpo.bp.116.004077