Does vitamin D supplementation reduce type 2 diabetes risk?

The morbidity and mortality rates of diabetes have been ever increasing year-on-year basis with approximately 400-million diabetes people; therefore, it represents a pressing issue of public health threat with huge socioeconomic impact worldwide that needs to be dealt with immediately. In fact, diabetes has become a global epidemic associated with the major cause of hospitalization and death among the aging population, where type 2 diabetes mellitus (T2DM) or, predominantly, obesity-associated T2DM accounts for >90% of human diabetes in clinical setting (1). Given that the current therapeutic modalities of T2DM are suboptimal with side effects, we should resort to some plain preventative approaches, such as physical exercise and lifestyle change as well as the use of dietary supplements and food additives, or nutraceuticals (2). Of particular interest in this context is the potential benefit of vitamin D supplementation to reduce hepatic insulin resistance and pancreatic islet dysfunctions, thus opposing the progression and development of obesity-associated metabolic diseases, such as T2DM and non-alcoholic fatty liver disease (NAFLD) (3). In confirmed, leveraging the advantage of vitamin D/analogue supplements may provide a scientific basis for the cost-effective approach to lowering or preventing T2DM risk and its related complications and sequelae