A quarterly publication of the Autism Research Institute

The Autism Research Review International is quarterly publication of the Autism Research Institute

Spring, 2023 | Number 2, Volume 37

Meta-analysis shows some benefits of supplementation with vitamin D, but no effect on core symptoms of ASD

Supplementation with vitamin D may help to reduce stereotypical behaviors in children with autism spectrum disorders (ASD) but does not appear to affect core symptoms or coexisting conditions, according to a new meta-analysis by researchers in China. 

Min Zhang and colleagues analyzed data from six randomized, controlled studies in their meta-analysis. In all, the studies involved 176 children with ASD. The researchers report that they detected no statistically significant differences between the vitamin D-supplemented groups and the placebo groups in terms of core symptoms and coexisting conditions, as measured by the Aberrant Behavior Checklist and the Social Responsiveness Scale However, they say, “Among the studies that used the GARS-2 [Gilliam Autism Rating ScaleSecond Edition], there was a significant difference in stereotyped behaviors between groups.” 

The researchers say their analysis indicates that children whose levels of vitamin D were the highest at the conclusion of the studies exhibited greater improvements than those with lower levels. Thus, they suggest, clinicians or researchers should measure vitamin D levels before, during, and after supplementation. They also say that age may be a factor, as some research shows greater gains in children with ASD who start taking vitamin D supplements when they are under three years of age. “Most participants in the included trials were older than five years,” they note, “and it is possible that less neuroprotection and benefits might be obtained from vitamin D supplementation because neuronal networks in these participants were already established, suggesting that vitamin D supplementation should be initiated as early as possible.” 

The researchers caution that even though this was a meta-analysis, the number of subjects was relatively small and larger studies are needed to determine the efficacy of vitamin D supplementation for individuals with ASD.


“Effects of vitamin D supplementation on children with autism spectrum disorder: A systematic review and meta-analysis,” Min Zhang, YiRan Wu, ZhaoXu Lu, MeiYan Song, XiaoLan Huang, LaLa Mi, Jian Yang, and Xiaodai Cui, Clinical Psychopharmacology and Neuroscience, May 2023 (free online). Address: Min Zhang, Beijing Municipal Key Laboratory of Child Development and Nutriomics, Capital Institute of Pediatrics, No. 2 Yabao Road, Chao Yang district, Beijing 100020, China, [email protected]