Clinical improvement following vitamin D3 supplementation in Autism Spectrum Disorder

Objective: High prevalence of vitamin D deficiency was previously reported in children with Autism Spectrum Disorder (ASD), but little is known about the efficacy of vitamin D3 treatment in ASD, although data from pilot studies seem promising. We hypothesized that serum vitamin D levels are reduced in ASD and correlate with the severity of disease. Also, we hypothesized that vitamin D3 treatment may be beneficial for a considerable portion of children with ASD.

Methods: In total, 215 children with ASD and 285 healthy control children were recruited in our study. Thirty seven of 215 ASD children received vitamin D3 treatment. The Autism Behaviour Checklist (ABC) and the Childhood Autism Rating Scale (CARS) were used to assess autism symptoms. High-performance liquid chromatography was used to assess the serum 25-hydroxyvitamin D [25(OH) D] level. Evaluations of ABC, CARS, and serum 25(OH) D levels were performed before and after 3 months of treatment.

Results: Serum levels of 25(OH) D were significantly lower in ASD children than typically developing children. Levels of serum 25(OH) D were negatively correlated with ABC total scores and language subscale scores. After vitamin D3 supplementation, symptom scores were significantly reduced on the CARS and ABC. In addition, the data also suggest that treatment effects were more pronounced in younger children with ASD.

Conclusion: Vitamin D deficiency might contribute to the aetiology of ASD. Supplementation of vitamin D3, which is a safe and cost-effective form of treatment, may significantly improve the outcome of some children with ASD, especially younger children (identifier ChiCTR-CCC-13004498).

Clinical trial registration: The trial 'Association of Polymorphisms of Vitamin D Metabolism-Related Genes With Autism and the Treatment of Autism with Vitamin D' has been registered at www.chictr.org/cn/proj/show.aspx? proj=6135 (identifier ChiCTR-CCC-13004498).