Vitamin D has important actions on glucose metabolism. These include improved insulin exocytosis, direct stimulation of insulin receptor, improved uptake of glucose by peripheral tissues, improving insulin resistance. It has got various pleiotropic effects like suppression of cell mediated immunity, regulation of cell proliferation, stimulation of neurotropic factors such as nerve growth factor, Glial cell line-derived neurotrophic factor, neurotropin, suppression of RAAS, reduction of albuminuria, immunomodulatory effects, and anti-inflammatory effects. Thus, vitamin D is implicated in many ways in the pathogenesis of retinopathy, neuropathy and nephropathy.  Aim of the Study : The purpose of the study is to assess the levels of 25- hydroxyl vitamin D in patients with type 2 diabetes mellitus and its association with diabetic nephropathy.  Materials and Methods : In this cross sectional study, the association between circulating 25-hydroxy vitamin D level and the presence of diabetic nephropathy in type 2 diabetes mellitus who attended medicine outpatient clinic and inpatients of medical wards. Our study included 206 patients which includes two groups, one group with 25(OH) D <30ng/ml of 72 patients and another group with 134 patients who had 25(OH)D>30ng/ml. Venous blood was drawn from the patients after an overnight fasting and serum creatinine was calculated using Jaffe method, Glycated haemoglobin - HbA1c was measured by an automated High performance liquid chromatography analyser. Serum 25(OH)D concentrations were measured using chemiluminescent immunoassay. Estimated Glomerular Filtration Rate e-GFR was estimated with the Four variable Modification of Diet in Renal Disease (MDRD) study equation.  Observation and Results : In our study total of 206 patients, 104 patients were female and 102 were males. With gender comparison, there occurs a statistically significant ‘p value’in female patients with Vit D<30ng/ml a mean of 61.2% compared with males with a mean of 38.8%. Here 71 patients with vitamin D deficiency which constitutes about 53% found to have diabetic nephropathy and in vitamin D sufficient patients, 30 patients which constitutes about 41.7% found to have diabetic which is statistically insignificant.  Conclusion : Vitamin D is found to have both direct action through vitamin D receptor activation and indirect action through regulation of calcium homeostasis and its effects on various pathogenesis and type2 diabetes which includes dysfunction of pancreatic beta cells, insulin action impairment and systematic information. Vitamin D is considered to be an important factor in modifying the risk of type2 diabetes mellitus and In type 2 Diabetes mellitus about 65% people found to have vitamin D deficiency according to our study