Is There any Correlation between Vitamin D Insufficiency and Diabetic Retinopathy

Introduction: It has been approved that Vitamin D deficiency has a role in increasing rate of cardio-vascular complications in diabetic patients. The aim of this study was to determine a relation between vitamin D level, which is an inhibitor of angiogenesis, and diabetic retinopathy and its risk factors.Materials & Methods: In a clinic-based cross sectional study two hundred thirty five type 2 diabetic patients older than 20 years were selected. Patients were classified according to ophthalmologic examination as following: no diabetic retinopathy (NDR) (n=153), non proliferative diabetic retinopathy (NPDR) (n=64) and proliferative diabetic retinopathy (PDR) (n=18). Study subjects were tested for fasting blood sugar, HbA1C, lipid profile, microalbuminuria, HsCRP, IGF1, insulin (in patients without history of insulin taking) and 25 hydroxy vitamin D levels. Vitamin D insufficiency was defined according to 25 hydroxy vitamin D level less than 30 ng/ml. The relationship between diabetic retinopathy and serum 25-hydroxyvitamin D insufficiency was evaluated.Results: The prevalence of diabetic retinopathy was 34.8% in our patients. Long duration of diabetes, hypertension, poor glycemic control, diabetic nephropathy, hyperinsulinemia and insulin resistance were risk factors for diabetic retinopathy but 25 (OH) D level was not significant different between NDR, NPDR and PDR groups. Correlation between 25 hydroxy vitamin D level and other known risk factors of diabetic retinopathy was not significant.Conclusion: This study did not find any association between diabetic retinopathy and its severity and vitamin D insufficiency. Vitamin D insufficiency was not related to risk factors of diabetic retinopathy.