PTH and diabetes mellitus: Our study showed that the 25(OH)D level had a significant positive correlation with eGFR, albumin, and calcium and a negative correlation with the UACR, creatinine, uric acid, PTH, etc. The results also demonstrated that DN patients with lower levels of 25(OH)D were more prone to progress to renal endpoints, which was independent of age, sex, course of diabetes, DR, creatinine, UACR, eGFR and pathological damage.