Impact of the COVID-19 Outbreak on Vitamin C and Vitamin D Supplement Use Among Adults: A Descriptive Cross-sectional Study in Larestan, Fars Province, Iran

Abstract

Background: During the COVID-19 lockdown, social and lifestyle habits, including supplement intake, changed substantially worldwide. However, information about these changes remains limited, and the determinants of increased supplement use during the pandemic are not well understood. Objectives: This cross-sectional study aimed to examine the impact of the COVID-19 lockdown on the use of vitamin C and vitamin D supplements among adults in Larestan. Methods: This descriptive cross-sectional study was conducted among adults aged 20 to 60 years in Larestan during the COVID-19 pandemic in 2022 - 2023. In total, 347 completed questionnaires were analyzed. Demographic characteristics, history of chronic diseases and disabilities, history of COVID-19 infection, and hospitalization due to COVID-19 were recorded. Quantitative data were compared using an independent-samples t-test and one-way analysis of variance when normality assumptions were met; otherwise, nonparametric tests, including the Wilcoxon and Kruskal-Wallis tests, were used. Results: During the COVID-19 outbreak, many participants increased their consumption of vitamin D and vitamin C supplements. Increased vitamin D consumption was associated with education level, COVID-19 infection among second-degree relatives, occupation, and awareness of the benefits of vitamin D for COVID-19 recovery and prevention. Increased vitamin C consumption was associated with chronic respiratory disease, education level, hospitalization due to COVID-19, occupation, personal COVID-19 infection, and awareness of the benefits of vitamin C supplementation for recovery and prevention. No significant relationship was found between increased consumption of these supplements and obesity, hypertension, heart disease, diabetes, chronic respiratory disease, kidney stones, respiratory symptoms of COVID-19, family income, or number of family members. Conclusions: Increasing public awareness of the potential benefits of supplements may help manage future respiratory pandemics and potentially reduce healthcare costs; however, further interventional studies are needed to confirm a causal relationship.