The effect of vitamin D treatment on proteinuria with diabetic nefhropaty patients

Background: Diabetic nephropathy is one of the major reasons of the end stage renal failure. Proteinuria indicates the level of the glomerular damage aswell accelerating the disease to the final stage kidney deficiency. In this study, the effects of adding vitamin D on the treatment of patients with diabetic nephropathy on the metabolism of proteinuria, lipid, and glucose was examined.Materials and Methods: Thirty patients being monitored with diabetic nephropathy diagnosed in Faculty of Medicine Endocrinology and Nephrology policlinics in Cukurova University were included in this study. Without changing anything in the treatment of the patients without an active infection, cardiac insufficiency, uncontrolled hypertension, serum creatine >2.0 mg/dL and with stable blood glucose, vitamin D 800 IU/daily was added if no contraindication was found. All along the monitoring process, the physical examinations of the patients were recorded. Blood pressure and body weight were monitored. At the beginning of the study (period [P] I), after 3 month treatment of vitamin D (P II), and after 3 month discontinue of vitamin D (P III), blood glucose, HbA1C, BUN, creatinine, Na, K, Ca, P, total protein, albumin, total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides and daily proteinuria were measured.Findings: Seven of the patients were using ACEI, 7 of them were using ARB, and 7 of them were using ARB+ACEI. 9 patients were not taking anti-hypertensive drugs. PI (at the beginning) versus PII (with vitamin D treatment); increase of HbA1C, serum albumin, total protein, vitamin D and calcium levels were statistically significant (p< 0,05). Statistically significant decreases were identified in PTH, daily proteiuria and microalbuminuria (For PTH p:0,017; daily proteinuria p: 0,011 and microalbuminuria p: 0,064). PII(with vitamin D treatment) versus PIII (after 3 month discontinue of vitamin D); decrease of serum albumin, total protein, vitamin D and calcium levels were statistically significant. İncrease at PTH, daily proteinuria and microalbuminuria statistically significant (For PTH p= 0,012; daily proteinuria p=0, 016; microalbuminuria p=0,03). For the patients with daily proteinuria > 0.5 g, vitamin D was more efficient to decrease proteinuria. No changes in blood lipids were identified, but LDL. During the treatment, no adverse situation occurred except for mild hypercalcemia.Conclusion: Vitamin D (800 IU/daily) added on the treatment of the patients with diabetic nephropathy was found statistically significant in decreasing proteinuria and correspondingly in increasing serum albumin level. Decrease of microalbuminuria was identified (p=0.064). No deterioration was observed in blood pressure, kidney function tests and lipid levels. However, inhibition in vitamin D dependent PTH levels, mild hypercalcemia and significant increase in HbA1C were observed. No significant change was identified in fasting glucose and body mass index. The effect of vitamin D did not change in patients taking antihypertensive. After ceasing vitamin D, all parameters including proteinuria, microalbuminuria and HbA1C changed back to the initials values. Consequently, regarding to its antiproteinuric effect, vitamin D was thought being a treating option for the patients with diabetic nephropathy.Key Words: Diabetic nephropathy, proteinuria, vitamin D.