Vitamin D in Autism Spectrum Disorder: A Critical Systematic Review of Evidence and Methodological Limitations

This systematic review examined serum vitamin D status and supplementation outcomes in children with autism, analyzing 8 observational studies and 3 high-quality randomized controlled trials. While some studies showed lower vitamin D levels in autistic children and one high-dose trial showed symptom improvements, the authors conclude current evidence does not support vitamin D supplementation as a general autism intervention, highlighting need for larger, better-controlled studies.