Role of vitamin D in immune function and type 1 diabetes

Vitamin D is not only essential for bone metabolism, but also has an additional immune-modulating effect on the immune system, which may play a role in the pathogenesis of several endocrine diseases. In this review, we debate the effects and recommendations of vitamin D supplementation, especially in the context of the nonclassical effects. Evidence from animal model and epidemiological studies supports a role for vitamin D in many endocrine conditions. Vitamin D supplementation may play a role in the prevention of type 1 diabetes mellitus. Although observational studies support a potential role of vitamin D in endocrine disease, high-quality evidence from clinical trials to establish a place for vitamin D supplementation in optimizing endocrine health are lacking. Based on observational studies, vitamin D deficiency should probably be avoided in individuals at high risk of developing type 1 diabetes, specifically in early life.