A double-blind, randomized, placebo-controlled trial of combined calcitriol and ergocalciferol versus ergocalciferol alone in chronic kidney disease with proteinuria

Abstract Background KDOQI guideline suggests that nutritional vitamin D should be supplemented in chronic kidney disease (CKD) patients who have vitamin D insufficiency/deficiency. However, there are scarce data regarding the additional benefit of active vitamin D supplement in CKD patients who were receiving nutritional vitamin D supplement. This study was conducted to explore the effect of adding active vitamin D to nutritional vitamin D supplement on proteinuria and kidney function in CKD with vitamin D insufficiency/deficiency. Methods This double-blind, randomized placebo-controlled trial was performed to answer the above question. Sixty-eight patients with CKD stage 3\u20134, urine protein to creatinine ratio (UPCR)\u2009>\u20091\ua0g/g, and serum 25OH-D level\u2009<\u200930\ua0ng/mL were enrolled. Patients were randomly assigned to receive 12-week treatment with oral ergocalciferol plus placebo ( n \u2009=\u200936) or oral ergocalciferol plus calcitriol ( n \u2009=\u200932). Results The mean baseline values of UPCR of both groups were comparable (3.6\u2009\ub1\u20093.8\ua0g/g in combined group and 3.5\u2009\ub1\u20093.0\ua0g/g in ergocalciferol group). Following 12-week treatment, there were significant reductions in UPCR from baseline in both groups (2.3\u2009\ub1\u20092.1\ua0g/g in combined group and 2.4\u2009\ub1\u20092.0\ua0g/g in ergocalciferol group). The percentage reductions in UPCR of both groups were not significantly different. The mean eGFR and blood pressure did not differ between baseline and 12-week follow-up and between both groups. No severe hypercalcemia or serious side effects were noted in both groups. Conclusions The proteinuria lowering effect of ergocalciferol in CKD patients with vitamin D deficiency was demonstrated. Additional calcitriol supplement did not have more effects on proteinuria. Trial registration (Thai Clinical Trials Registry (TCTR) 20140929002 ). Date of registration: September 27, 2014