Pleiotrophic Effects of Vitamin D in Proteinuric Chronic Kidney Disease Patients

OBJECTIVE: Proteinuria is an important marker that accelerates chronic kidney disease. Known antiproteinuric treatments are not always sufficient. In recent years, animal studies have shown that vitamin D has positive effects on inflammation in the kidney, glomerulosclerosis, interstitial fibrosis. The aim of our study was to investigate the effect of vitamin D on proteinuria in patients with proteinuric chronic kidney disease (CKD).

MATERIAL and METHODS: Thirty-five patients with proteinuric chronic kidney disease (CKDp) were included in the study [Study Group(SG)]. Vitamin D3 (300000 u / 21 d for 3 months) was added to therapy without any drugs modifications. Thirty-nine patients was consisted CKDp (CG). None of the patients had used vitamin D and/or phosphorus-binding medication in the previous 6 months. The results of daily proteinuria and biochemical tests at the beginning of study and the end of 3 months were recorded.

RESULTS: In the SG, there was significant improvement in proteinuria (median 1813 mg to 1395 mg p = 0.03), serum total protein and albumin (p=0.04 and p=0.02 respectively) at the end of 3 months. The BUN and creatinine values did not change. There was no significant difference in any parameter in CG. The percentage of patients with reduced proteinuria according to baseline was higher in SG (74%) when compared to CG (43%) (p=0.007).

CONCLUSION: In CKDp patients, vitamin D for 3 months significantly decreased proteinuria without causing a deterioration in renal function or an adverse event. Vitamin D may therefore be an alternative option to anti-proteinuric treatment in proteinuric CKD patients, in addition to its other known effects.