Role of vitamin A in type 2 diabetes mellitus biology: effects of intervention therapy in a deficient state.

Diabetes has emerged as the biggest pandemic of our times, growing parallel to obesity. Insulin treatment regimens have been unable to completely inhibit protein glycation, which is responsible for the development of increased oxidative stress in diabetic tissues. Coupled with recent evidences that highlight the role of reactive oxygen species in the onset and progression of type 2 diabetes mellitus (T2DM), the antioxidants have taken prime focus as a possible intervention strategy. Studies have established a role of antioxidant vitamins C and E in improving patient condition in the past. Vitamin A, in addition to its role as an antioxidant, boasts a pleiotropic role in cell regulation through its action on gene regulation, maintenance of epithelial cell integrity, and resistance to infection. Studies have also ascribed a role to vitamin A in up-regulating the antioxidant enzyme functions in the body. Additionally, a link has been found between diabetes and deficient vitamin A levels indicating vitamin A supplementation may have a role in T2DM biology. This review therefore focuses on the vitamin A intervention in T2DM patients having deficient in vitamin A.