The role of vitamin D in insulin regulation, immunity, and homeostasis in diabetes has been extensively studied. Vitamin D deficiency is linked to an increased incidence of type 2 diabetes (T2D), islet dysfunction, and insulin resistance. Studies show that vitamin D supplementation in deficient subjects can slow T2D progression and improve insulin sensitivity. Vitamin D can directly regulate functional genes involved in insulin activity and act on tissue-resident immune cells to reduce inflammation and prevent islet dysfunction. Evidence also supports the role of vitamin D in preventing type 1 diabetes (T1D) pathogenesis. While extensive trials are needed to evaluate the potential of vitamin D intake for preventing or reversing T2D, current evidence highlights the crucial role of vitamin D in diabetes prevention and management.
