Mitochondrial dysfunction has also been reported in vitamin D deficient individuals which has been attributed to intra-mitochondrial calcium deficiency or deficient enzyme function of the oxidative pathway ( by direct effect of vitamin D on enzyme gene or protein expression). Thus, vitamin D may improve the statin-mediated changes in cardiorespiratory fitness and mitochondrial function by improving the enzymatic machinery involved in oxidative phosphorylation which is blocked by statin. This study is being done to look for the effect of vitamin D supplementation on simvastatin-mediated change in exercise-mediated cardiorespiratory fitness and skeletal muscle mitochondrial content in adults with type 2 diabetes