It focused on investigating the prospective association between habitual use of Vitamin D supplements and the risk of COVID-19 infection. A prospective study was conducted and it was found that habitual use of vitamin D supplements was associated with a lower risk of COVID-19 infection, independent of factors, such as lifestyle, socio-economic status, prevalent chronic diseases, and circulating vitamin D levels. It also found that the Circulating vitamin D levels at baseline or genetically predicted vitamin D have no association with the risk of COVID-19 infection. The major strengths of this study were found to be prospective design, availability of data on factors, like- lifestyle, socio-economic status, and social psychological factors, and support from previously conducted studies, reporting the beneficial effects of vitamin D supplementation on alleviating the risk of acute respiratory tract infections. It also mentioned several potential limitations of the study, including the lack of data on the severity of COVID-19.
