The classical risk factors of diabetes are unable to explain the endemic raise in diabetes. In spite of the well established actions of vitamins as antioxidants, the association studies between antioxidant vitamin status and its ameliorative effects in diabetes has no conclusive results at all and the interventional studies have no favorable effect of vitamin supplementation, and other studies indicated a possible link between the increased incidence of T2DM in antioxidant supplemented populations. To show role of chronic antioxidant vitamin (C and E) supplementation for the increased risk of T2DM in rats. In the present study, rats were divided into three groups: control group which were given distilled water only, Vitamin C supplemented group which were orally supplemented with vitamin C (100, 200,500 mg/kg) and Vitamin E supplemented group which were orally supplemented with vitamin E (50,100,200 mg/kg). Chronic supplementation of rats with antioxidant vitamins C and E caused significant elevation in the fasting blood glucose, insulin and HOMA which indicated a diabetogenic effect. Also, pancreatic tissues showed elevated GLUT 2, glucokinase and NRF2 and decreased UCP2 upon supplementation with antioxidant vitamins. It could be concluded that the chronic supplementation with antioxidant vitamins have diabetogenic effect through many mechanism that may involve pancreas and peripheral tissues.