Randomized trial of two maintenance doses of vitamin D in children with chronic kidney disease.

Background Correction of nutritional vitamin deficiency is recommended in children with chronic kidney disease (CKD). The optimal daily dose of vitamin D to achieve or maintain vitamin D sufficiency is unknown. Methods We conducted a phase III, double-blind, randomized trial of two doses of vitamin D3 in children ≥ 9 years of age with CKD stages 3-5 or kidney transplant recipients. Patients were randomized to 1000 IU or 4000 IU of daily vitamin D3 orally. We measured 25-hydroxvitamin D (25(OH)D) levels at baseline, 3 months and 6 months. The primary efficacy outcome was the percentage of patients who were vitamin D replete (25(OH)D ≥ 30 ng/mL) at 6 months. Results Ninety-eight patients were enrolled: 49 randomized into each group. Eighty (81.6%) patients completed the study and were analyzed. Baseline plasma 25(OH)D levels were ≥ 30 ng/mL in 12 (35.3%) and 12 (27.3%) patients in the 1000 IU and 4000 IU treatment groups, respectively. At 6 months, plasma 25(OH)D levels were ≥ 30 ng/mL in 33.3% (95% CI: 18.0-51.8%) and 74.4% (95% CI: 58.8-86.5%) in the 1000 IU and 4000 IU treatment groups, respectively (p = 0.0008). None of the patients developed vitamin D toxicity or hypercalcemia. Conclusions In children with CKD, 1000 IU of daily vitamin D3 is unlikely to achieve or maintain a plasma 25(OH)D ≥ 30 ng/mL. In children with CKD stages 3-5, a dose of vitamin D3 4000 IU daily was effective in achieving or maintaining vitamin D sufficiency. Clinical trial registration ClinicalTrials.gov identifier: NCT01909115.