Objective To evaluate the effect of increasing sunshine time or 1, 25(OH)₂D₃ supplement on improving Vitamin D blood level and reduction of microalbuminuria in early stage diabetic nephropathy (DN) patients. Methods A total of 150 early stage type 2 DN patients with serum 25(OH)D₃ lower than 15 mg/L were included.The patients were divided into sunshine group (n=50), 1, 25(OH)₂D₃ supplement group (n=50), and control group (n=50).After three-month treatment, serum 25(OH)D₃ level and urinary albumin to creatinine ratio(ACR)were compared among these three groups. Results Before treatment, there were no differences in serum 25(OH)D₃, ACR, HbA1c among the three groups.After three-month treatment, serum 25(OH)D₃ level was significantly improved in sunshine group, and ACR was reduced significantly in both sunshine group and 1, 25(OH)₂D₃ group. Conclusion Increasing sunshine time can improve Vitamin D level and reduce microalbuminuria in early stage diabetic nephropathy patients.