Roles of active forms of vitamin D in supporting innate immune systems and in reducing excess inflammation in COVID-19

A reduced supply of micronutrient vitamin D leads to a more severe course of coronavirus infection (COVID-19). Vitamin D deficiency is combined with a decrease in innate antiviral immunity and excess of inflammation. Vitamin D supplementation stimulates the synthesis of antibacterial peptides and is important for weakening the cytokine storm, reducing excessive acute and chronic inflammation, and also for compensating for chronic comorbid pathologies. Active forms of vitamin D (alfacalcidol, etc.) are of particular importance for compensating for vitamin D deficiency in elderly patients, endocrine-immune dysfunction, sarcopenia, chronic renal failure (in which the metabolism of vitamin D in the kidneys is disturbed).