Vitamin D and Its Regulatory Role in Pancreatic β-Cell Function: Implications for Diabetes

Pancreatic β-cell dysfunction represents a key pathological feature in the development and progression of diabetes mellitus. Accumulating evidence has confirmed the widespread expression of vitamin D receptors in pancreatic tissue, suggesting a potential regulatory role in glucose metabolism. Epidemiological studies have consistently reported an association between vitamin D deficiency and increased diabetes incidence, impaired insulin secretion, and poor glycemic control. Vitamin D has been known to support pancreatic islet function by modulating β-cell proliferation, enhancing insulin synthesis and secretion, and mitigating inflammatory responses and oxidative stress. This review systematically discusses vitamin D metabolism and physiological functions, the role of pancreatic islet dysfunction in diabetes pathogenesis, vitamin D receptor expression and activity in pancreatic tissue, epidemiological correlations between vitamin D status and diabetes risk, and the molecular mechanisms through which vitamin D influences β-cell function. Furthermore, this review examines the therapeutic implications of vitamin D supplementation for the prevention and management of diabetes. It contributes to a growing body of knowledge that informs potential strategies to improve diabetes outcomes through vitamin D-related pathways.