ABSTRACT
Background: COVID-19 still needs to be further investigated for risk and preventing factors. Various factors are known to negatively affect the course of disease in patients suffering from COVID-19. As it is known, vitamin D affects the immune system and a vitamin D deficiency is often seen in patients with ARDS. Thus, we hypothesize that vitamin D could be one of those influencing factors. However, an association between the vitamin D level and the severity of the disease remains unclear. Aim(s): This study aims to contribute to the clarification whether there is a correlation between the serum 25- hydroxyvitamin D level and the severity of COVID-19 disease in hospitalized SARS-CoV-2 positive patients. Method(s): This is a retrospective, observational study in a single-center setting in Switzerland. Data of approximately 1200 hospitalized patients between January 2020 and December 2021 with an available and current 25- hydroxyvitamin D value and a SARS-CoV-2 positive immune status will be analysed. Quantitative and descriptive statistics as well as multivariable regression are used to assess the relationships between the serum 25- hydroxyvitamin D level and the severity of COVID-19 disease, adjusted for known confounding variables of vitamin D deficiency and COVID-19 severity such as age, sex and comorbidities. Result(s): As the study is ongoing, no results are available yet, but will be by the time of the congress. Conclusion(s): The results of this study may contribute to new treatment and prevention methods of COVID-19 together with more evidence from clinical trials to assess the causality of the relationship between vitamin D level and the severity of COVID-19 disease.