Vitamin D is a micronutrient and is one of the most critical nutrient, whose connection to autism is the most thoroughly studied. The relationship is straightforward, although its observational evidence. There have been multiple studies performed which have shown that observing vitamin D levels is crucial in autistic children, as well as autistic adolescents. 

Foods rich in Vitamin D are - Fortified foods, Spinach, Fatty fish (tuna, salmon, etc.), Eggs, Mushrooms etc.

Please find below few research informed insights on Vitamin D and Autism: 

  • In one study, children who received vitamin D supplementation experienced increased cognitive awareness, social awareness, and social cognition compared to those who only received the placebo. Vitamin D supplementation significantly decreased repetitive hand movements, random noises, jumping, and restricted interests.
  • Another study showed that Vitamin D supplementation improves the typical symptoms of autism spectrum disorder, as indicated by reduced Social Responsiveness Scale and Child Autism Rating Scale scores; thus, it is beneficial for autistic children.
  • Multiple studies in the last five years have shown that Vitamin D deficiency or insufficiency in more than 60% of autistic children. 

Vitamin D has also been associated with poor sleep quality and decreased sleep time. As we all know, the best version of Vitamin D comes from the sun. In the summer one tends to have the highest concentrations of Vitamin D and in winter our levels tend to drop. It is particularly important to monitor your child’s Vitamin D levels. If you are concerned that your child is not getting enough nutrition from food or if your child is low in sunlight due to winter or if you notice your child tends to have more sleep issues during the winter months, it might be worth getting their vitamin D checked. Please have a conversation with your doctor.


  • Glock, M. (2020, November 30). Widespread vitamin D deficiency again found in children, teens with ASD. Autism Research Institute. (Link)
  • Souders, M. C., Mason, T. B. A., Valladares, O., Bucan, M., Levy, S. E., Mandell, D. S., Weaver, T. E., & Pinto-Martin, J. (2009). Sleep Behaviors and Sleep Quality in Children with Autism Spectrum Disorders. Sleep, 32(12), 1566–1578. (Link)
  • Johnson, C. R., Smith, T., DeMand, A., Lecavalier, L., Evans, V., Gurka, M., Swiezy, N., Bearss, K., & Scahill, L. (2018). Exploring sleep quality of young children with autism spectrum disorder and disruptive behaviors. Sleep Medicine, 44, 61–66. (Link)
  • Şengenç, E., Kıykım, E., & Saltik, S. (2020). Vitamin D levels in children and adolescents with autism. The Journal of International Medical Research, 48(7). (Link