Effects of Normalizing Vitamin D Levels on Glomerular Filtration Rate and Urinary Microalbumin-to-Creatinine Ratio in Patients with Type 2 Diabetes

Objective: To investigate the effects of normalizing vitamin D levels (≥20 ng/ml) on renal function indicators in patients with type 2 diabetes. Methods: Sixty-six patients with type 2 diabetes were enrolled. After vitamin D supplementation, vitamin D levels, urinary microalbumin-to-creatinine ratio (UACR), and estimated glomerular filtration rate (eGFR) were measured. Based on post-supplementation vitamin D levels, patients were divided into normal vitamin D level group (≥20 ng/ml) and vitamin D deficiency group (<20 ng/ml). Differences in UACR and eGFR between the two groups were compared. Results: The eGFR in the normal vitamin D level group was significantly higher than that in the vitamin D deficiency group, while the UACR in the normal vitamin D level group was significantly lower than that in the vitamin D deficiency group (P < 0.05). Conclusions: Normalization of vitamin D levels (≥20 ng/mL) in patients with type 2 diabetes may be associated with improved renal function indicators.