Low socioeconomic status predicts vitamin D status in a cross-section of Irish children

Vitamin D is essential for bone and muscle health with adequate status in childhood crucial for normal skeletal development. We aimed to investigate vitamin D status in a convenience sample (n = 1226) of Irish children (aged 1-17 years) who had serum 25-hydroxyvitamin D (25(OH)D) tested by request of their GP at a Dublin Hospital between 2014 and 2020. We examined predictors including age, sex, season and socioeconomic status (SES). Vitamin D deficiency (<30 nmo1/1) was prevalent affecting 23 % and was more common in disadvantaged areas (34 %) and in those aged >12 v. <= 12 years (24 % v. 16 %, P = 0.033). The greatest predictor was SES (disadvantaged v. affluent, OR 2.18, CI 1.34, 3.53, P = 0.002), followed by female sex (OR 1.57, CI 1.15, 2.14, P = 0.005) and winter season (October to February, OR 1.40, CI 1.07, 1.84, P = 0.015). A quarter of our sample of children were deficient, rising to one-third in those in disadvantaged areas. Females and those aged over 12 years had a higher prevalence of deficiency. Public health strategies to improve vitamin D status in Irish children, including systematic food fortification may need to be considered to address this issue.