Background: New evidence show high prevalence of vitamin D deficiency in many countries and some studies support a possible link between low vitamin D status and atopy-related phenotypes in children. The objective of this study was to determine the prevalence of vitamin D deficiency in a population sample of Asian children and to investigate the association between serum 25-hydroxyvitamin D [25(OH)D] concentrations and total and allergen-specific immunoglobulin E (IgE) levels. Methods: Serum 25(OH)D concentrations were measured by a new automated electrochemiluminescense-based assay, Elecsys Vitamin D total assay (Roche Diagnostics, Mannheim, Germany), in a population-based sample of 1315 Asian children aged 5 – 18 years in the Prediction of Allergies in Taiwanese CHildren (PATCH) study. Serum levels of total and allergen-specific IgE were determined by ImmunoCAP and ImmunoCAP Phadiatop Infant, respect-Tively. Results: The mean concentration of serum 25(OH)D was 20.4 ng/ml (SD: 7.1 ng/ml). Vitamin D insufficiency (defined as serum 25(OH) D < 30 ng/ml) was observed in 90.3% of children. Vitamin D deficiency (defined as serum 25(OH) D < 20 ng/ml) was present in 51.0% of children. The serum 25(OH)D concentration was not significantly associated with total IgE (P>0.05) or allergic sensitisation, defined as a positive Phadiatop Infant test result, (P>0.05). Older age, female gender, higher body mass index, winter/spring months, and environmental tobacco smoke exposure were associated with low vitamin D concentrations (all P< 0.01). Conclusion: Vitamin D deficiency is remarkably common in this population-based sample of Asian children, suggesting that millions of Asian children living in Taiwan may have suboptimal levels of vitamin D. This population-based study provides evidence against the association of vitamin D status with either total IgE levels or allergic sensitisation in Asian children. The relationship between vitamin D status and allergic diseases merits further study.
