Autism spectrum disorder and vitamin D status: A cross-sectional study of children in a developing country in Southeast Asia

Abstract Background Determine the prevalence and risk factors of vitamin D deficiency ( Method Cross-sectional study of children with ASD at a tertiary hospital. Children with vitamin D deficiency ( Results There were 103 participants (85.4 % male). Mean age: 6.2 years (SD = 2.4), 19 % were vitamin D deficient and 42 % were insufficient. Mean vitamin D concentration was 45.8 nmol/L (SD = 13.5). Female gender was significantly associated with vitamin D deficiency (OR 5.05, 95 % CI: 1.56, 16.31, p = 0.007). Post-vitamin D treatment, there was a significant reduction in CARS-2 scores (p  Conclusions Nearly two-thirds (61 %) of Malaysian children with ASD have vitamin D deficiency (19 %) and insufficiency (42 %). Vitamin D treatment among vitamin D deficient children with ASD resulted in improvement in ASD symptom severity but not behavioural symptoms.