Infant Exposure to Excessive Vitamin D: A Risk Factor for Autism

Abstract

Autism is a neurodevelopmental disorder that is normally defined by its behavioral characteristics but also often features a known biochemical gestalt. This biochemical gestalt includes a Th2 skew to the immune system, endothelial damage, oxidative stress, excessive neuronal connectivity, and dysregulated monoamines. In sufficient doses, oral supplementation with Vitamin D induces a Th2 skew to the immune system, endothelial damage, oxidative stress, excessive neuronal connectivity, and dysregulated monoamines. A number of genetic syndromes that are comorbid with autism feature excessive calcification. One of these, Williams syndrome, features hypercalcemia that is associated with elevations in blood levels of vitamin D. Vitamin D consumption among babies and toddlers in the United States is high relative to historical norms and has been increasing in recent decades coincident to the rise in autism rates. Low rates of autism have been observed among the Amish and in Cuba where there is no supplementation or fortification with vitamin D. Autism is more common among males than females and large doses of oral vitamin D are more toxic to males than females. These facts support the hypothesis that oral vitamin D consumption among the young may be a risk factor in inducing autism.