“Sunlight” Vitamin D3—Multifaceted, Mysterious, Necessary

Abstract

The importance of vitamin D3 for maintaining the level of health in conditions of the acute respiratory and vascular infectious pathology of COVID-19 is considered. Physiological vitamin deficiency has been documented as a negative predictor of virus exposure and disease severity. A complex of clinical and experimental studies document that vitamin D3 performs the function of controlling hemovascular homeostasis—the endothelium of the vascular wall, a complex of immunological reactions, coagulation and rheological properties of blood, systemic hemodynamics, etc. The variety of effects is determined by the transcriptional role of the vitamin D3 receptor, which expresses gene targets for synthesis functional protective proteins. The possibilities of supplementation, maintaining the level of vitamin D3 and its chemical metabolites, for the preventive and therapeutic strategy of COVID-19 are considered.