Vitamin D Deficiency associated with Diabetic Nephropathy in Type 2 Diabetes: Study

A new study published in the journal of Diseases found a significant association between vitamin D deficiency and diabetic nephropathy (DN) in patients with type 2 diabetes mellitus (T2DM). The patients with DN showed poorer glycemic control, dyslipidemia, impaired renal function, and a higher prevalence of vitamin D deficiency.

Diabetic nephropathy is a leading cause of chronic kidney disease and end-stage renal failure worldwide. It also contributes significantly to cardiovascular complications, reduced quality of life, and rising healthcare costs. While vitamin D deficiency has long been linked to impaired kidney function, its specific role in diabetic kidney damage has remained uncertain-until now.

This research examined 399 adults attending a tertiary endocrine clinic, including 299 patients diagnosed with diabetic nephropathy and 100 patients with T2DM but without kidney involvement. The study analyzed demographic information, diabetes history, kidney function, lipid and liver profiles, and serum 25-hydroxyvitamin D levels to explore how vitamin D status differed between the 2 groups.

The results revealed that patients with diabetic nephropathy were notably older and had more advanced stages of chronic kidney disease when compared to those without nephropathy. Most DN patients were in moderate stages of kidney impairment, whereas the majority of patients without DN had preserved kidney function. Albuminuria was also substantially higher in the DN group, with many showing moderate to severe protein loss in the urine.

Biochemically, the DN group had poorer long-term blood sugar control, higher levels of urea and creatinine, lower serum albumin, abnormal lipid profiles, elevated liver enzymes, and higher uric acid levels. These patterns undergo a widespread metabolic and organ stress among patients with kidney involvement.

Over one-third of patients with diabetic nephropathy were vitamin D deficient, when compared to only 8% of patients with diabetes but no kidney disease. Statistical modeling showed that patients without nephropathy were far less likely to have vitamin D deficiency or insufficiency. Even after adjusting for age, duration of diabetes, kidney function, and blood sugar control, the strong protective association against vitamin D deficiency remained.

Although the study cannot prove that low vitamin D causes kidney disease, due to its cross-sectional design, it strongly suggests that deficiency is closely linked with the presence and severity of diabetic nephropathy. Overall, this study finds that routine monitoring of vitamin D levels in people with type 2 diabetes could help identify those at higher risk of kidney complications.

Source:

Bashir, S., Ishaq, G. M., Mushtaq, I., Ganie, M. A., Wani, I., Alanazi, M., Asiri, I., Hussain, A., Khan, K. U., & Anwar, S. (2025). Association of vitamin D deficiency with diabetic nephropathy in type 2 diabetes: A hospital-based cross-sectional study. Diseases (Basel, Switzerland), 13(12), 405. https://doi.org/10.3390/diseases13120405