Diabetes mellitus and obesity are a growing overall medical issues, particularly in developed nations. Vitamin D deficiency is pandemic that has been involved in a different kind of disease. This study was intended to detect the effect of vitamin D deficiency and vitamin D receptor polymorphisms on type 2 diabetes mellitus (T2DM) patients through induction of obesity. 80 Egyptians T2DM patients and 20 non diabetic subjects were included in our research. Diabetic cases were categorized into two subgroups according to diabetic complications. PCR-RFLP for vit D receptor polymorphisms and vit D level were assessed to all subjects. The deficiency of vitamin D was more prevalent in diabetic cases than in control cases. There was significant difference between control and diabetic patients in genotyping of FokI (VDR 2228570 C) and TaqI (VDR rs731236 T) polymorphisms. The results of our study revealed that vitamin D deficiency could be a contributing factor for T2DM rising among Egyptian patients. Additionally, there was a genetic variation in the VDR genes FokI and TaqI related to diabetic mellitus in Egyptian patients. Manuscript profile