Treatment of vitamin D insufficiency in children and adolescents with inflammatory bowel disease: a randomized clinical trial comparing three regimens.

Context: Vitamin D insufficiency [serum 25-hydroxyvitamin D (25OHD) concentration less than 20 ng/ml] is prevalent among children with inflammatory bowel disease (IBD), and its treatment has not been studied. Objective: The aim of this study was to compare the efficacy and safety of three vitamin D repletion regimens. Design and Setting: We conducted a randomized, controlled clinical trial from November 2007 to June 2010 at the Clinical and Translational Study Unit of Children's Hospital Boston. The study was not blinded to participants and investigators. Patients: Eligibility criteria included diagnosis of IBD, age 5-21, and serum 25OHD concentration below 20 ng/ml. Seventy-one patients enrolled, 61 completed the trial, and two withdrew due to adverse events. Intervention: Patients received orally for 6 wk: vitamin D-2, 2,000 IU daily (arm A, control); vitamin D-3, 2,000 IU daily (arm B); vitamin D2, 50,000 IU weekly (arm C); and an age-appropriate calcium supplement. Main Outcome Measure: We measured the change in serum 25OHD concentration (Delta 25OHD) (ng/ml). Secondary outcomes included change in serum intact PTH concentration (Delta PTH) (pg/ml) and the adverse event occurrence rate. Results: After 6 wk, Delta 25OHD +/- SE was: 9.3 +/- 1.8 (arm A); 16.4 +/- 2.0 (arm B); 25.4 +/- 2.5 (arm C); P (A vs. C) = 0.0004; P (A vs. B) = 0.03. Delta PTH +/- SE was -5.6 +/- 5.5 (arm A); -0.1 +/- 4.2 (arm B); -4.4 +/- 3.9 (arm C); P = 0.57. No participant experienced hypercalcemia or hyperphosphatemia, and the prevalence of hypercalciuria did not differ among arms at follow-up. Conclusions: Oral doses of 2,000 IU vitamin D-3 daily and 50,000 IU vitamin D-2 weekly for 6 wk are superior to 2,000 IU vitamin D-2 daily for 6 wk in raising serum 25OHD concentration and are well-tolerated among children and adolescents with IBD. The change in serum PTH concentration did not differ among arms. (J Clin Endocrinol Metab 97: 2134-2142, 2012)