Vitamin D is essential in the uptake and metabolism of calcium and is intrinsic for bone health. Childhood/adolescence are periods of intensive bone growth, with vitamin D deficiency causing improper bone mineralisation, resulting in rickets. Recent evidence suggests that the prevalence of rickets is increasing globally(Reference Creo, Thacher and Pettifor1), with levels in the UK the highest seen in five decades(Reference Goldacre, Hall and Yeates2). Vitamin D intakes have been found to be insufficient (<5ug/day) in up to 94% of 600 Irish children age 5–12 years(3), with little recent evidence on vitamin D status. The aim is to assess vitamin D status in a sample of children and adolescents (1–18 years) via a cross sectional analysis of GP requested vitamin D samples analysed at St James's Hospital (SJH).
The SJH catchment area (53°N) includes Dublin City, County and Eastern Leinster. 25(OH)D concentrations (measured by LC-MS/MS) of children age 1–17 years (N = 1,269) between 2014–2020 were analysed. Results were analysed with percentage of deficiency (<30 nmol/L) and insufficiency (30–49 nmol/L). This data was stratified by age (<12 years, >12 years), gender and season (Low; Dec-May vs. High; Jun-Nov), and statistically analysed.
Vitamin D deficiency was highly prevalent in this population with 23% <30 nmol/L and more than half (51%) with insufficient vitamin D status (<50 nmol/L). The geometric mean 25(OH)D was 43.81 nmol/L (SD 25.47). Those over 12 years were more likely to be deficient vs. under 12 years (24% vs. 16%, p = 0.033), with girls more likely to be deficient vs. boys (25% vs. 18%, p = 0.003). Deficiency and insufficiency were also more common in low season vs. high season (30% vs 16%, p < 0.001), (32% vs. 23%, p < 0.001, respectively).
Vitamin D deficiency and insufficiency is highly prevalent in this childhood population, with girls, those over 12 years and those assessed in the low vitamin D season most at-risk. These results indicate that low vitamin D status is more common in this childhood cohort versus previously published results in an adult survey of the same population(Reference Scully, Laird and Healy4). As such, further analysis is planned to explore factors contributing to VDD in this cohort including location, trends in retesting and over time. Poor vitamin D status is common in a large survey of Irish children age 1–17 years, and as such public health measures, including the consideration of a policy for mandatory fortification, should be activated to address this issue.
Financial Support: This research is partially funded by Mercers’ Institute and Glanbia PLC. Glanbia has no role in study design, data collection and analysis, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.