Vitamin D may influence the development of autism

A new US study reports that vitamin D helps to regulate three genes involved in autism.

The researchers identified three genes that are abnormally expressed in autism and are directly regulated
by vitamin D (1). Vitamin D seems to up-regulate the gene involved in central serotonin production and to down-regulate the peripheral serotonin gene. That may explain why children with autism have decreased brain serotonin levels and elevated blood serotonin concentrations when their vitamin D levels are low. The fact that estrogen greatly increases expression of the central serotonin gene, may explain why autism is five times more common in boys than in girls. Moreover, autistic children have low levels of oxytocin, a hormone that promotes social behavior. Oxytocin also seems to be directly controlled by vitamin D. If children are deficient in vitamin D, they also have low levels of oxytocin.

The scientists concluded that a supplementation with vitamin D during pregnancy may be a practical and affordable solution to help prevent autism in children and possibly ameliorate some symptoms of the dis- order. To date, many studies of vitamin D levels in autism show that children with autism are vitamin D deficient (2). Autism spectrum disorders (ASDs) cover a range of neurodevelopmental disorders affecting 1% of children born in the United States. The disorders are characterized by impaired reciprocal social interactions, communication deficits and propensity for repetitive behaviors.

1. Patrick R. P. and Ames B. N. Vitamin D hormone regulates serotonin synthesis. Part 1: relevance for autism. The FASEB Journal. Published online February 2014.
   
2. Baio J. Prevalence of Autism Spectrum Disorders – Autism and Developmental Disabilities Monitoring Network, 14 Sites, United States, 2008. In Centers for Disease Control and Prevention: Morbidity and Mortality Weekly Report (MMWR). 2012; pp. 1–19, Centers for Disease Control and Prevention, Atlanta, GA, USA.