Cholecalciferol v. ergocalciferol for 25-hydroxyvitamin D (25(OH)D) repletion in chronic kidney disease: a randomised clinical trial

Patients with chronic kidney disease (CKD) demonstrate complex mineral metabolism derangements and a high prevalence of vitamin D deficiency. However, the optimal method of 25-hydroxyvitamin D (25(OH) D) repletion is unknown, and trials analysing the comparative efficacy of cholecalciferol and ergocalciferol in this population are lacking. We conducted a randomised clinical trial of cholecalciferol 1250 mu g (50 000 IU) weekly v. ergocalciferol 1250 mu g (50 000 IU) weekly for 12 weeks in forty-four non-dialysis-dependent patients with stage 3-5 CKD. The primary outcome was change in total 25(OH) D from baseline to week 12 (immediately after therapy). Secondary analyses included the change in 1,25-dihydroxyvitamin D (1,25(OH)(2)D), parathyroid hormone (PTH), D-2 and D-3 sub-fractions of 25(OH) D and 1,25(OH) 2D and total 25(OH) D from baseline to week 18 (6 weeks after therapy). Cholecalciferol therapy yielded a greater change in total 25(OH) D (45.0 (SD 16.5) ng/ml) v. ergocalciferol (30.7 (SD 15.3) ng/ml) from baseline to week 12 (P < 0.01); this observation partially resulted from a substantial reduction in the 25(OH) D-3 sub-fraction with ergocalciferol. However, following cessation of therapy, no statistical difference was observed for total 25(OH) D change from baseline to week 18 between cholecalciferol and ergocalciferol groups (22.4 (SD 12.7) v. 17.6 (SD 8.9) ng/ml, respectively; P = 0.17). We observed no significant difference between these therapies with regard to changes in serum PTH or 1,25(OH)(2)D. Therapy with cholecalciferol, compared with ergocalciferol, is more effective at raising serum 25(OH) D in nondialysis-dependent CKD patients while active therapy is ongoing. However, levels of 25(OH)D declined substantially in both arms following cessation of therapy, suggesting the need for maintenance therapy to sustain levels.