Utilization of Dietary Supplements in People with the Atopic Triad in Korea: A Cross-Sectional Study Using KNHANES (2018–2021)

<i>Background and Objectives</i>: Studies investigating the types of dietary supplements associated with the atopic triad using large-scale data remain limited. We assessed the prevalence of the atopic triad, the types of dietary supplements used, and their associations in Korean adults using a 4-year national survey data. <i>Materials and Methods</i>: This cross-sectional study utilized data from the Korea National Health and Nutrition Examination Survey (2018-2021). Adults aged ≥ 19 years were included. Descriptive statistics were used to summarize participants' overall characteristics and estimate the national prevalence of the atopic triad, defined as a diagnosis of asthma, allergic rhinitis, or atopic dermatitis. Logistic regression analyses were conducted using each atopic condition as a dependent variable, with the types of dietary supplements currently used as independent variables. Covariates included socioeconomic status, lifestyle factors, frailty, and diet. Dietary supplements were categorized as multivitamins/minerals, vitamin C, vitamin D, vitamin A/lutein, propolis, omega-3, probiotics, red ginseng, calcium, or iron. <i>Results</i>: A total of 18,182 adults were analyzed, representing an estimated 52.8 million adults (mean age: 47 years; 50% male). Of these, 21% reported a history of any atopic triad, and 61% were current supplement users. Logistic regression showed significantly higher odds of all three atopic conditions among users of propolis (asthma: OR 1.90, 95% CI 1.04-3.47; allergic rhinitis: OR 1.64, 95% CI 1.25-2.17; atopic dermatitis: OR 2.04, 95% CI: 1.18-3.52), and higher odds of allergic rhinitis among users of probiotics (OR 1.21, 95% CI 1.06-1.38) and vitamin D (OR 1.43, 95% CI 1.16-1.75). <i>Conclusions</i>: A positive association was found between propolis use and all three atopic conditions. Also, a positive association was found between probiotics or vitamin D use and allergic rhinitis. We did not find significant associations with the other supplements. Further research in establishing causal relationships between the dietary supplements and atopic conditions are needed.