The authors report that immune system dysregulation is common in autism spectrum disorder (ASD). The question is why does this immune dysregulation occur and what has caused such dysregulation to skyrocket in recent decades?
Vitamin D deficiency produces very similar immune dysregulation to what the authors reported.
Thus the vitamin D theory of ASD (vitamin D deficiency being the environmental risk factor for this highly heritable disorder) is consistent with the authors work. Three recent studies, using community controls, have found 25(OH)D levels are significantly lower in children with ASD. Two of the studies below (Mostafa et al and Gong et al) also found ASD severity, as rated on standard ASD rating scales, is inversely correlated with 25(OH)D levels. Mostafa et al found an R value of -.86 for the association of serum 25(OH)D with ASD severity.
There is a plethora of basic science explaining why low gestational or early childhood 25(OH)D levels would adversely affect brain development.
Furthermore, the vitamin D theory of autism explains most of the epidemiological facts of ASD.
70% of American toddlers do not take the American Pediatric Association’s recommended vitamin D supplement of 400 IU/day and few toddlers or pregnant women get any sunshine due to the sun scare. As vitamin D fortified milk consumption and sun exposure has declined, so have toddlers and pregnant women’s vitamin D levels. The dramatic increase in the incidence of ASD occurred during the same time vitamin D levels were falling in toddlers and pregnant women.
Some autism researchers seem cognizant of the entire body of autism research. For example, a group of well-known European ASD researchers, including Professor Christopher Gillberg of the Gillberg Neuropsychiatric Institute, have recently called for the need for “urgent research” into the vitamin D deficiency theory of ASD.
As the authors point out, immune dysregulation is common in ASD. The question is why now and what is causing it?
John J Cannell, MD
Vitamin D Council