A study published in the November 21, 2016 issue of the Journal of Child Psychology and Psychiatry looked at vitamin D supplementation in children with autism spectrum disorder (ASD). The study was led by Saad et al and involved 109 children ages 3 - 10 years. Participants either received vitamin D3 (at 300 IU per kg per day not exceeding 5000 IU per day) or placebo for 4 months. All the children were assessed for ASD severity and social maturity prior to the study and at the end of the 4 months. A significant improvement in ASD symptom severity was noted in the participants who received vitamin D3, but not in the participants who received the placebo. Because we produce vitamin D3 internally during summer months, it tends to be a very easily tolerated supplement and this study points to it being an important part of the health support plan for people with ASD.