SARS-CoV-2 is the causative agent of the latest pandemic infectious disease, COVID-19, which constitues a serious risk to human health. SARS-CoV2 infection causes immune activation and systemic hyperinflammation which can lead to acute respiratory distress syndrome (ARDS), one of the leading causes of morbidity and mortality in patients with a severe form of SARS-CoV-2 infection. ARDS victims are characterized by a significant increase in IL-6 and IL-1, as well as endothelial damage and increased barrier permeability. Macrophage activation, associated with the cytokine storm, promotes dysregulation of innate immunity and in very severe forms of infection leads to damage and failure of numerous organs. Vitamin D and its receptor, vitamin D receptor (VDR), exert a critical role in infections due to their remarkable impact on both innate and adaptive immune responses as well as on the suppression of the inflammatory process. Vitamin D reduces the intensity of the cytokine storm and also reduces the systemic inflammatory response by stimulating the differentiation of regulatory T cells. It also induces the production of endogenous antimicrobial peptides that protect the body from attacking respiratory viruses. The protective properties of vitamin D supplementation have been supported by numerous observational studies and by meta-analysis of clinical trials for prevention of viral acute respiratory infections. Considering this, it is recommended to maintain an optimal level of vitamin D in the blood, as this improves the work of the immune system, which enables the body to effectively fight all pathogens, including viruses.