Vitamin D and Autism Spectrum Disorder: A Literature Review

Abstract

Low vitamin D status in early development has been hypothesised as an environmental risk factor for Autism Spectrum Disorder (ASD), given the concurrent increase in the prevalence of these two conditions, and the association of vitamin D with many ASD-associated medical conditions. Identification of vitamin D-ASD factors may provide indications for primary and secondary prevention interventions. We systematically reviewed the literature for studies on vitamin D-ASD relationship, including potential mechanistic pathways. We identified seven specific areas, including: latitude, season of conception/birth, maternal migration/ethnicity, vitamin D status of mothers and ASD patients, and vitamin D intervention to prevent and treat ASD. Due to differences in the methodological procedures and inconsistent results, drawing conclusions from the first three areas is difficult. Using a more direct measure of vitamin D status—that is, serum 25(OH)D level during pregnancy or childhood—we found growing evidence for a relationship between vitamin D and ASD. These findings are supported by convincing evidence from experimental studies investigating the mechanistic pathways. However, with few primary and secondary prevention intervention trials, this relationship cannot be determined, unless randomised placebo-controlled trials of vitamin D as a preventive or disease-modifying measure in ASD patients are available.

Autism genes are selectively targeted by environmental pollutants including pesticides, heavy metals, bisphenol A, phthalates and many others in food, cosmetics or household products

“…Low vitamin D status during pregnancy or childhood has also been associated with autism [176]. Severe maternal hypothyroxinaemia during early pregnancy has also been linked to an increased incidence of autism in the offspring [177].…”

Pharmacobiological Treatments in Autism Spectrum Disorders

“…In ASD studies, although omega-3-fatty acid supplementation had no significant beneficial effects in adult patients [37], another study on children have shown significant improvements in social and communication responses [38]. Among vitamins, vitamin B6 and magnesium [39], and vitamin D [40], have shown beneficial effects in few studies, while others such as vitamin A, and vitamin B12 and folic acid have been proposed as potential treatment options for ASD. Minerals such as magnesium [39], iron [41], and zinc [42], have also been recommended for nutritional therapies in ASD.…”

Autism genes are selectively targeted by environmental pollutants including pesticides, heavy metals, bisphenol A, phthalates and many others in food, cosmetics or household products

“…Lower nocturnal melatonin or melatonin metabolite concentrations have been observed in autism and melatonin treatment improves sleep quality and daytime behaviour in autistic subjects [66,67].Low vitamin D status during pregnancy or childhood has also been associated with autism [68]. Severe maternal hypothyroxinaemia during early pregnancy has also been linked to an increased incidence of autism in the offspring [69].…”