Differences and determinants of vitamin D deficiency among UK biobank participants: A cross-ethnic and socioeconomic study

Background: The public health relevance of true vitamin D deficiency is undisputed, although controversy remains regarding optimal vitamin D status. Few contemporary cross-ethnic studies have investigated the prevalence and determinants of very low 25-hydroxyvitamin D [25(OH)D] concentrations. Methods: We conducted cross-ethnic analyses on the prevalence and determinants of vitamin D deficiency (25(OH)D < 25 nmol/L) using data from 440,581 UK Biobank participants, of which 415,903 identified as White European, 7880 Asian, 7602 Black African, 1383 Chinese, and 6473 of mixed ancestry. Determinants of vitamin D deficiency were examined by logistic regression. Results: The prevalence of vitamin D deficiency was highest among participants of Asian ancestry (57.2% in winter/spring and 50.8% in summer/autumn) followed by those of Black African ancestry (38.5% and 30.8%, respectively), mixed (36.5%, 22.5%), Chinese (33.1%, 20.7%) and White European ancestry (17.5%, 5.9%). Participants with higher socioeconomic deprivation were more likely to have 25(OH)D deficiency compared to less deprived participants (P = <1 x 10-300); this pattern was more apparent among those of White European ancestry and in summer (Pinteraction <6.4 x 10-5 for both). In fully-adjusted analyses, regular consumption of oily fish was associated with reduced odds of vitamin D deficiency across all ethnicities, while outdoor-time in summer was less effective for Black Africans (OR 0.89, 95% CI 0.70, 1.12) than White Europeans (OR 0.40, 95% CI 0.38, 0.42). Conclusions: Severe vitamin D deficiency remains an issue throughout the UK, particularly in lower socioeconomic areas. In some groups, levels of deficiency are alarmingly high with one-half of Asian and one-third of Black African ancestry populations affected across seasons. Key messages: The prevalence of vitamin D deficiency in the UK is alarming, with certain ethnic and socioeconomic groups considered particularly vulnerable. (c) 2020 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Automated summary

The study highlighted the alarming prevalence of vitamin D deficiency in the UK, especially among certain ethnic and socioeconomically vulnerable groups.