Background: Type 2 diabetes mellitus (DM) is one of the most common diseases worldwide. Early diagnosis and management has a significant role in reducing complications. Vitamin D is a fat-soluble vitamin that showed important functions regarding calcium and phosphate homeostasis, immunity and insulin resistance. There is a well-established link between vitamin D level and type 2 DM. Objective(s): The aim of this study was to assess serum 25(OH) vitamin D₃ level in type 2 diabetic subjects and to investigate its relation to glycemic control, proinflammatory markers and insulin resistance. Methods: The study included 60 type 2 diabetic subjects in the age group 40-70 years and 30 controls matched for age and gender. Pregnant females, renal, hepatic and cancer patients were excluded from the study. All participants were subjected to detailed history taking, anthropometric measurements including weight, height and waist circumference, full clinical examination and laboratory investigations including serum 25(OH)vitamin D_3, FSG, HbA₁c, serum insulin, and CRP.HOMA-IR was calculated using FSG and serum insulin values. Results: The mean serum concentration of 25(OH) vitamin D3 was significantly lower in type 2 diabetics compared to controls (2.91±4.20 ng/ml, 12.04 ±7.74 respectively) (p<0.001). There was a significant increase in BMI, WC, FSG, HbA1c, serum insulin, and HOMA-IR in type 2 diabetics compared to controls (p<0.05). A statistical significant negative correlation was found between 25(OH) vitamin D3 level and the following parameters: BMI (r=-0.584, p<0.001), WC (r=-0.233, p=0.027), FSG (r=-0.735, p<0.001), HbA1C (r=-0.387, p<0.001), HOMA-IR (r=-0.729, p<0.001), serum insulin (r=-0.272, p=0.010). Meanwhile, 25(OH) vitamin D3 did not significantly correlate with the proinflammatory marker CRP (r=-0.126, p=0.238). Conclusion Subjects with type 2 DM have low25(OH) vitamin D₃ level compared to healthy normal individuals. The negative association of 25(OH) vitamin D3 with glycemic control and its irrelevance to the proinflammatory markers suggest that vitamin D may be an important determinant in the pathogenesis of type 2 DM. Hence, cautious Vitamin D supplementation may have a therapeutic potential in prevention and management of Type 2 DM.