Summary: The ongoing coronavirus disease 19 (COVID-19) pandemic, which started at the end of 2019 in China and spread quickly across the entire world population, remains the greatest challenge we have faced since World War Two. The SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) virus binds to angiotensin-converting enzyme 2 receptors in the respiratory tract of infected patients starting the intense inflammatory response leading to acute respiratory distress syndrome and severe pneumonia, with high mortality rates. During the last two decades, several studies have shown that, in addition to the regulation of mineral homeostasis, vitamin D has various non-calcemic effects in practically all tissues, exerting there anti-inflammatory, antiapoptotic, and anti-fibrotic actions. It regulates cell proliferation and differentiation, modulates the innate and adaptive immune responses, and function of the central nervous and cardiovascular system, as well as many other organs. The deficiency of vitamin D is highly prevalent and is associated with various diseases like hypertension, diabetes, cancer, autoimmune disorders, and infections, bacterial and viral, such as influenza, SARS-CoV, and SARS-CoV-2. In the article, the current knowledge on the relationship of 25(OH)D status and COVD-19 incidence and severity, as well as potential mechanisms of vitamin D protective role against the disease is reviewed.