International Journal of Preventive Medicine (Int J Prev Med)2008-78021472023091928542854ENDepartment of Nutrition Research, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, IranDepartment of Nutrition Research, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, IranDepartment of Nutrition Research, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, IranDepartment of Nutrition Research, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, IranGastrointestinal and Liver Diseases Research Center (GILDRC), Iran University of Medical Sciences, Tehran, IranCommunity Nutrition Office, Deputy of Health, Iran Ministry of Health and Medical Education, Tehran, IranCommunity Nutrition Office, Deputy of Health, Iran Ministry of Health and Medical Education, Tehran, IranCommunity Nutrition Office, Deputy of Health, Iran Ministry of Health and Medical Education, Tehran, IranCentre for Intelligent Healthcare, Coventry University, Coventry, CV1 5FB, U. KDepartment of Nutrition Research, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, IranDepartment of Nutrition Research, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran20230919Background: The coronavirus disease 2019 (COVID‑19) pandemic elicited the general population to use various dietary supplements (DSs) and nutraceuticals as a protective means against the disease. The present study aimed to evaluate changes and certain determinants of DS intake during the COVID‑19 lockdown among Iranian households. Methods: This nationwide cross‑sectional study was conducted from April 4 to April 25, 2020, during which Iran was in lockdown. To collect data, a web‑based electronic self‑administered questionnaire was created. The data were compared among provinces based on their food security situations. Results: A total of 21,290 households were included in the analyses. Approximately 27% of the households were using DSs after the epidemic. The most common DSs used were vitamin D (42%) and vitamin C (20%), followed by multi‑vitamin (16%), zinc (9%), omega‑3 (6%), vitamin A (4%), and probiotics (3%). Logistic regression analysis revealed that DS intake was directly associated with the household income but inversely with household size and the food security status of the provinces. DS intake was positively associated with the presence of high‑risk persons in the households, the education of the households’ head, and the presence of a person with a history of COVID‑19 within the household. Conclusions: During epidemic lockdown, DS use was remarkably increased among the Iranian households. Apart from the debatable usefulness of DSs against COVID‑19, the inverse association of DS use with a household’s income and provincial food security well indicates inequity in accessibility to DS. Actions to improve the nutritional status of the under‑privileged populations including targeted supplementation are strongly recommended.http://ijpm.mui.ac.ir/index.php/ijpm/article/view/2854http://ijpm.mui.ac.ir/index.php/ijpm/article/download/2854/717718677