Serum 25-hydroxyvitamin D and adult-onset atopic dermatitis: insights from two large national cohorts

Abstract

Objective:The incidence rate of adult-onset atopic dermatitis (AOAD) is rising. There is still limited evidence regarding the association between serum 25 hydroxyvitamin D (25(OH)D) and the risk of AOAD. This study determined the extent to which a lower level of serum 25(OH)D is associated with the risk of AOAD in the two large, population-based cohorts.Methods:We included 6340 participants from the Korean National Health and Nutrition Examination Survey (KNHANES) and 229260 participants from the UK Biobank cohort. The primary outcomes were the occurrence of AOAD. The multivariable logistic regression analyses and multivariable Cox proportional hazards regression were performed to estimate odds ratios (ORs), hazard ratios (HRs) and 95% confidence intervals (CIs) of serum 25(OH)D in relation to incident AOAD. We further conducted the restricted cubic splines, subgroup analysis and sensitivity analysis to enhance the robustness of our results.Results:In this study, individuals in a state of 25(OH)D deficiency or insufficiency were significantly associated with the risk of AOAD compared to participants with sufficient 25(OH)D (KNHANES: OR, 1.80 [95% CI, 1.01-3.02]); OR, 1.61 [95% CI, 1.00-2.59]); UK Biobank: HR, 1.20 [95% CI, 1.04-1.38]); HR, 1.31 [95% CI, 1.09-1.58]).Additionally, a linear association was observed between serum 25(OH)D levels and the risk of AOAD in both cohorts.Conclusions:Our findings revealed that elevated levels of serum 25(OH)D robustly associated with a decreased risk of AOAD. These results hold considerable public health implications, indicating that the serum 25(OH)D may offer a practical and efficient means of detecting high-risk individuals and informing tailored intervention strategies. For 4 individuals with low levels of 25 (OH) D, regular supplementation of vitamin D may be a beneficial strategy for preventing AOAD.