P65 Vitamin D deficiency is associated with atopic dermatitis severity in a Bangladeshi population living in the UK

Abstract

Abstract Atopic eczema is a common chronic inflammatory skin condition with considerable heterogeneity. South Asian people living in the UK frequently have low vitamin D levels, and those with atopic disease can present with severe eczema. The association between vitamin D insufficiency and eczema severity and the role of vitamin D supplementation in atopic eczema is inconsistent, and it is under-researched in people with Asian ancestry living in low-ultraviolet (UV) areas. This cross-sectional study investigates the association between serum 25-hydroxy vitamin D3 [25(OH)D3] and eczema severity in a cohort of South Asian children and young adults living in the UK. Eligible participants were Bangladeshi children and young adults aged 0–30 years with eczema, participating in the THEA study. Data for the study were collected via parent/patient self-reporting, clinical history and examination and hospital databases. Levels of 25(OH)D3 were documented retrospectively, if available, from hospital databases. Eczema severity was classified by an Eczema Area and Severity Index (EASI) score less than or greater than 10. Multivariate logistic regression was used to adjust for confounding factors. In total, 682 patients were recruited between May 2018 and December 2021. The EASI score was available for 681 participants [mean (SD) 7.9 (9.1)] and 25(OH)D3 results were available for 49.7% (n = 339). Eighty-four per cent were deficient (< 25 nmol L−1) or insufficient (< 50 nmol L−1) in 25(OH)D3. Vitamin D3 levels were inversely correlated with the EASI score (Spearman’s rank R2 = –0.22; P < 0.001). After adjustment, there was a significant association between eczema severity (EASI > 10) and lowest 25(OH)D3 [odds ratio (OR) 0.973, 95% confidence interval (CI) 0.956–0.988; P < 0.001], working class (OR 0.542, 95% CI 0.295–0.991; P = 0.047), previous immunosuppression/biologic therapy (OR 2.432, 95% CI 1.189–5.077; P = 0.016), mild-to-moderate potency topical steroid use on the face and neck (OR 3.566, 95% CI 1.730–7.696; P < 0.001) and topical calcineurin inhibitor use on the face and neck (OR 3.421, 95% CI 1.140–10.288; P = 0.027). These findings demonstrate an inverse correlation between 25(OH)D3 level and eczema severity in a cohort of exclusively South Asian children and young adults living in a low-UV region. Vitamin D plays a role in the modulation of proteins required for skin barrier function and regulation of the innate immune system, suggesting that vitamin D deficiency in this population may contribute to inflammation in the skin. Further research on the role of vitamin D supplementation in atopic eczema, particularly in people with skin of colour, is required.