ESPE Abstracts

Objectives: Vitamin D deficiency is prevalent in pediatric population. Since low compliance may inhibit appropriate vitamin D supplementation in daily dosing regimen, intermittent high dose administration may be considered. We aimed to evaluate the efficacy and safety of monthly administration of oral cholecalciferol compared with daily dosing regimen in adolescents with vitamin D deficiency.

Methods: This retrospective study included 299 children and adolescents who were vitamin D deficient (serum 25 hydroxy vitamin D (25(OH)D) concentration of <20 ng/mL) and diagnosed with precocious puberty on GnRH agonist between December 2019 and November 2022. 100 children received 1,000 IU of oral cholecalciferol every day [daily group], and 199 children received 25,000 IU of oral cholecalciferol every 4 weeks [monthly group]. After propensity score matching (PSM) using age, sex, season, and baseline 25(OH)D level, 100 patients of each daily supplement group and monthly supplement group were matched. Levels of blood chemistry, including 25(OH)D, total calcium, phosphorus, and alkaline phosphatase (ALP), were examined.

Results: Baseline 25(OH)D levels did not differ between two groups (mean ± SD, 14.0 ± 3.1 in daily group vs. 14.0 ± 3.2 ng/mL in monthly group, P=0.99). After median follow-up of 5.9 months (5.9 ± 2.5 months), increase in serum 25(OH)D concentrations were higher in monthly group than in daily group (10.7 ± 4.7 vs. 8.4 ± 7.1 ng/mL, P=0.025). The corrected dose-response was also higher in monthly group than in daily group (12.0 ± 5.3 vs. 8.4 ± 7.1 ng/mL increase per 1,000 IU/day, respectively, P=0.001). The proportion of patients attaining non-deficient vitamin D status (25(OH)D > 20 ng/mL) after treatment was 79.0% and 59.0% in monthly and daily groups, respectively (P=0.004). Hypercalcemia was not observed in both groups.

Conclusions: Monthly administration of oral cholecalciferol 25,000 IU every 4 weeks showed higher efficacy and equivalent safety profiles compared with conventional daily administration in adolescents with vitamin D deficiency. It needs to be further investigated whether monthly administration of cholecalciferol have more benefits in pediatric population.