ESPE Abstracts

Introduction: No consensus on vitamin D (VitD) deficiency screening in children and adolescents exists.

Aim: To evaluate a sample of patients in whom VitD dosing was performed and determine the rationale for this assessment.

Methods: Retrospective, longitudinal study of pediatric patients, from a Portuguese tertiary hospital, who had at least two 25(OH)D level blood sampling between March 2019 and March 2021. Children with less than 12 months were excluded given the routine VitD supplementation in this age group.

Results: From a total 1083 patients, 223 were eligible for analysis: 51% female gender, 82% Caucasians, median age of 12.5 years (IQR 6.5) and median SDS-BMI 1.14 (IQR 2.18). Median 25(OH)D blood level was 51 nmol/L (IQR 26), with 9% having VitD deficiency (<30nmol/L) and 37% insufficiency (30-50nmol/L). The 25(OH)D level was significantly influenced by the reason for testing (higher values in opportunistic screening, P=0.015), season (lower in winter, P<0.001), gender (P=0.04), age (r= -0.21, P=0.001) and by SDS-IMC (r= -0.17, P=0.011). VitD supplementation was offered in 90% and 74% patients with deficiency and insufficiency, respectively, with significant improvement in levels (37 vs. 54nmol/L, P<0,001) after a median of 5 months of therapy (IQR 5). Most vitD assessments were requested in a screening setting (39%), namely in patients with obesity, type 1 diabetes mellitus, intestinal disease with impaired absorption, use of drugs such as anti-epileptics and corticosteroids. Of the patients screened, 56% had abnormal levels (12% deficiency and 44% insufficiency), and vitD supplementation was prescribed in 42%, with a significant improvement in vitD levels (40 vs. 61mmol/L, P<0.001), and a reduction in the prevalence of VitD deficiency from 20 to 2%. Of the patients screened for vitD deficiency who did not get supplementation, there were no statistically significant differences in the median 25(OH)D value, but the prevalence of the deficit increased from 3 to 5% in a median of 11 months (IQR 8).

Discussion: The dosage of 25(OH)D has important limitations, starting with the determination of normal cut-off levels, to the typical seasonal variation, the influence of obesity, among others. Screening for vitD deficiency in high-risk patients, has a reasonable foundation, however, the cost-effectiveness is questionable. In our study we found a large proportion of at-risk patients with deficit and/or insufficiency, so one may therefore ask whether routine supplementation is not more valuable, at least in the months of less sun exposure.