Abstract：Autism spectrum disorder（ASD）is a highly heterogeneous neurodevelopmental disorder. Vitamin D is a common fat-soluble vitamin, and its effects are closely related to nervous system development in addition to affecting calcium and phosphorus metabolism in the body. Recent studies have shown that serum vitamin D levels are negatively correlated with the severity of ASD. Vitamin D deficiency during pregnancy or early fetal development, which is one of the most important risk factors for the development of ASD, can affect brain development and lead to long-term or even permanent damage to learning processes, memory formation, and cognitive function. In addition, vitamin D supplementation can improve core symptoms of ASD children and, to some extent, reduce the risk of developing ASD. This paper reviewed the metabolism and physiology of vitamin D, the relationship between vitamin D and ASD, and its role in the prevention and treatment of ASD.
