Serum vitamin D and parathormone (PTH) concentrations as predictors of the development and severity of diabetic retinopathy

Background: Vitamin D is suggested to be an inhibitor of angiogenesis. The degree of severity of diabetic retinopathy (DR) may be related to serum vitamin D concentration. Aim: Investigating vitamin D and parathormone (PTH) concentrations as predictors of the development and severity of diabetic retinopathy. Methods: Two hundred diabetic patients presenting with suspected diabetic retinopathy were investigated, levels of vitamin D [25(OH) D3 and Calcitriol] and PTH were measured. Diabetic retinopathy was assessed using 7-field stereoscopic Fundus photography. Results: Mean serum concentration of 1, 25 dihydroxy vitamin D 3 (1, 25(OH) 2 D3) was significantly lower in diabetic subjects with retinopathy than in diabetic subjects with no retinopathy and there is a significant negative correlation between the mean level of 1, 25(OH) 2 D3 and the degree of severity of retinopathy. Level of PTH was significantly higher in severe NPDR and PDR compared to patients with no retinopathy. Conclusions: Low levels of vitamin D might be a risk marker of development or progression of diabetic retinopathy. It might be advisable that detailed ophthalmologic examination is needed for diabetics whose serum 1, 25(OH) 2D3 concentrations gradually decreased. The measurement of serum 1, 25(OH) 2 D3 concentrations could become a useful biochemical means to predict the severity of DR in patients with diabetes mellitus.