Vitamin D and Autism Spectrum Disorder?

This study found impressive results - improvement in autistic behaviors in children diagnosed with autism spectrum disorder (ASD) with four months of daily vitamin D supplementation. Children in the placebo group did not show improvement. A nice aspect of the study was that the children were randomly assigned  to a placebo or a vitamin D group (so that the groups were not self-selected) and it was double-blinded (so no one knew who was getting the vitamins - again to prevent bias). This was a preliminary study - meaning more studies are needed, but it would be amazing if these results hold up... From Science Daily:

Vitamin D supplements may benefit children with autism spectrum disorder

Studies have shown an association between the risk of autism spectrum disorder and vitamin D insufficiency. In this latest study, 109 children with autism spectrum disorder were randomized to receive four months of vitamin D3 supplementation or a placebo."Autism symptoms -- such as hyperactivity, social withdrawal, and others -- improved significantly following vitamin D3 supplementation but not after receiving placebo," said Dr. Khaled Saad, lead author of the Journal of Child Psychology and Psychiatry study.

Excerpts from the original study from  The Journal of Child Psychology and Psychiatry: Randomized controlled trial of vitamin D supplementation in children with autism spectrum disorder

Autism spectrum disorder (ASD) is a frequent developmental disorder characterized by pervasive deficits in social interaction, impairment in verbal and nonverbal communication, and stereotyped patterns of interests and activities. It has been previously reported that there is vitamin D deficiency in autistic children; however, there is a lack of randomized controlled trials of vitamin D supplementation in ASD children.

This study is a double-blinded, randomized clinical trial (RCT) that was conducted on 109 children with ASD (85 boys and 24 girls; aged 3–10 years). The aim of this study was to assess the effects of vitamin D supplementation on the core symptoms of autism in children. ASD patients were randomized to receive vitamin D3 or placebo for 4 months. The serum levels of 25-hydroxycholecalciferol (25 (OH)D) were measured at the beginning and at the end of the study. The autism severity and social maturity of the children were assessed by the Childhood Autism Rating Scale (CARS), .... 

Supplementation of vitamin D was well tolerated by the ASD children. The daily doses used in the therapy group was 300 IU vitamin D3/kg/day, not to exceed 5,000 IU/day. The autism symptoms of the children improved significantly, following 4-month vitamin D3 supplementation, but not in the placebo group. This study demonstrates the efficacy and tolerability of high doses of vitamin D3 in children with ASD.   

Recently, Wang et al. (2016) performed a systematic review and meta-analysis of all studies on serum concentration of 25 (OH)D in ASD (Wang et al., 2016). Eleven studies were included, accounting for a total of 870 ASD patients and 782 healthy controls. Serum levels of 25 (OH)D in participants with ASD were significantly lower than those in controls. They concluded that low vitamin D might serve as a risk factor for autism spectrum disorder (Wang et al., 2016). 

In a recent survey, our research group measured 25 (OH)D in 122 ASD children (3–9 years old) and 100 healthy children as controls (Saad, Abdel-Rahman, et al., 2015). The ASD group showed a significantly lower level of serum 25 (OH)D compared with the control group (p < .0001). The study found highly significant inverse correlations between serum 25 (OH)D levels and autism rating scales. In the second part of the previous study (Saad, AbdelRahman, et al., 2015), an open-label trial of 83 subjects who completed a 3-month therapy with high daily doses of vitamin D (300 IU/kg/day) was performed. Collectively, 80.7% of the children with ASD had significantly improved outcome, which was mainly in the sections of the CARS and ABC subscales that measure behavior, stereotypy, eye contact, and attention span (Saad, Abdel-Rahman, et al., 2015).