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

Randomized clinical trial in children and adolescents with inflammatory bowel disease and vitamin D insufficiency (serum 25OHD ≤ 20 ng/mL). Active arm sizes were 24 randomized/20 completed for daily vitamin D2, 24 randomized/21 completed for daily vitamin D3, and 23 randomized/20 completed for weekly vitamin D2.

Three oral vitamin D repletion regimens were compared over 6 weeks: vitamin D2 2,000 IU daily, vitamin D3 2,000 IU daily, and vitamin D2 50,000 IU weekly. The active preparations were liquid formulations given by mouth.

The more effective regimens for raising serum 25OHD over 6 weeks were vitamin D3 2,000 IU daily and vitamin D2 50,000 IU weekly; both outperformed vitamin D2 2,000 IU daily. Mean 25OHD increased by 9.3 ± 1.8 ng/mL with daily D2, 16.4 ± 2.0 ng/mL with daily D3, and 25.4 ± 2.5 ng/mL with weekly D2, with follow-up levels of 25.7 ± 2.2, 31.5 ± 1.9, and 40.8 ± 2.6 ng/mL, respectively. Vitamin D3 produced a greater rise than vitamin D2 at the same 2,000 IU daily dose, and 95% of participants in the daily D3 and weekly D2 arms exceeded 20 ng/mL versus 75% in the daily D2 arm. All regimens were safe and well tolerated, with no hypercalcemia or related toxicity and no meaningful between-group differences in PTH change.

The trial was short and relatively small, with only 20 to 21 completers per arm, which limits precision for comparative efficacy and safety. Outcomes were primarily biochemical over 6 weeks, so durability of response, longer-term safety, and clinical relevance beyond serum 25OHD repletion remain uncertain. Generalizability may be limited to similar pediatric inflammatory bowel disease patients with vitamin D insufficiency treated at a single center.