Objective: To investigate the levels of vitamin D and the correlation between DPN and vitamin D in elderly patients with diabetic peripheral neuropathy(DPN). Methods: A total of 849 patients aged 60 years and over admitted into endocrinology department from June 2016 to September 2017 were enrolled in this retrospective case-control study.According to DPN diagnostic criteria, patients were divided into the non-DPN group(n=542)and the DPN group(n=307). The 25(OH)-vitamin D[25(OH)D]level and blood biochemical parameters were determined and compared between the two groups.The risk factors for DPN were analyzed using logistic regression analysis and plotting receiver operating characteristic(ROC)curves. Results: The mean of serum 25(OH)D level in the 849 patients was 43.9±19.4 nmol/L.Serum 25(OH)D level was lower in the DPN patients than in the non-DPN patients[(40.9±20.4)nmol/L vs.(45.7±18.6)nmol/L, P<0.05]. The incidence of 25(OH)D deficiency was higher in the DPN group than in the non-DPN group(72.3% or 222/307 vs. 64.6% or 350/542, P<0.05). Binary logistic regression analysis indicated that 25(OH)D was a protective factor for DPN(OR=0.980, 95% CI: 0.964~0.995, P<0.05)and the disease duration was a risk factor for DPN(OR=1.048, 95% CI: 1.027~1.070, P<0.001). ROC analysis indicated that the diagnostic cut-off value of serum 25(OH)D for predicting DPN was 37.5nmol/L, with a Youden index of 0.17, sensitivity of 0.65 and specificity of 0.52. Conclusions The 25(OH)D level is much lower in diabetic patients, especially in DPN patients.Higher 25(OH)VD level might be a protective factor for DPN, and vitamin D might be one of potential biomarkers for DPN in diabetic patients.