The aim of this review was to provide an update of the vitamin D role in modulating the immune response against respiratory viral infections and its preventive and therapeutic potential in these diseases.The paper presents results of studies revealing the pathophysiological mechanisms of the vitamin D participation in the innate and adaptive immune response to an infectious agent, of the vitamin D level association with acute respiratory viral infections, influenza, COVID-19 and pneumonia.The features of the cholecalciferol supplementation to optimize the body status of vitamin D are described.