The study measured blood vitamin D levels from 4,200 pregnant women during two-time points during pregnancy and found that those women that were deficient during both points measured were more likely to have a child with autism. This suggests that vitamin D deficiency throughout pregnancy may increase the risk of autism and that pregnant women should measure their vitamin D levels and supplement with vitamin D accordingly. I’m particularly excited about this research because it confirms my 2014 publication where I proposed that vitamin D regulates serotonin, which is a brain morphogen that shapes the structure and wiring of the brain during early brain development, and that maternal vitamin D deficiency could disrupt fetal brain development and lead to autism.