Vitamin D levels in children with autism spectrum disorders and normal children: a comparative cross-sectional study from South Kerala

Background: Epidemiological evidence indicates that vitamin D deficiency during critical periods may increase the risk of neurodevelopmental disorders including autism spectrum disorder. The present study aimed to assess and compare the vitamin D levels of children with autism spectrum disorder (ASD) and neurotypical children and also to explore the relationship between vitamin D status and the severity of ASD symptoms. Methods: This comparative cross-sectional study was conducted among children with ASD and children without any neuro developmental disorders. About 207 children aged two to six years were enrolled, comprising 105 participants with ASD and 102 who did not have an ASD diagnosis. ASD diagnosis was done using DSM-5 criteria and severity was assessed using CARS-2 ST scale. Serum 25-hydroxyvitamin D levels were obtained for every participant in the study. Statistical analyses included chi-square and independent t-tests, with significance set at p