With the change of lifestyle,the obese population is gradually increasing,and the prevalence of type 2 diabetes mellitus(T2DM)is increasing year by year,while the age of onset is declining year by year.Diabetic retinopathy(DR),as one of the common complications of T2DM,has a serious impact on the quality of life of patients.At present,there is no way to predict and completely stop the progression of DR.Studies have shown that vitamin D supplementation can effectively alleviate DR in vitamin D deficiency patients,which is expected to become a new idea and method to predict and treat DR.This article-reviews the role of vitamin D in the occurrence and development of DR,as well as its therapeutic effect and mechanism on DR,in order to provide a basis for the application of vitamin D supplementation in the prevention and treatment of DR.