Abstract
Vitamin D and its biologically active form kalcitriol participate in a lot of physiological processes in the human body. Calcitriol plays a key role in the regulation of calciumphosporus metabolism and its effect on cell differentiation and immune system is also important.
It affects especially the mechanisms of innate immunity, but its activity is very variable. In the case of infection and cancer it works as immunostimulator, while rather as an immunosupressive agent in the case of autoimmunity.
Regarding these characteristics, vitamin D can be used to prevent some infectious, malignant and autoimmunity diseases. Calcitriol and its synthetic analogues represent drugs that can bring a benefit into autoimmunity and posttrasplantation treatment.
Their therapeutical effect as well as their safety administration in these indications are necessary to be verified in clinical studies.