Type 1 diabetes mellitus is a chronic autoimmune disease associated with degeneration of
pancreatic β-cells that results in an inability to produce insulin and the need for exogenous
insulin administration. It is a significant global health problem as the incidence of this
disorder is increasing worldwide. The causes are still poorly understood, although it
certainly has genetic and environmental origins. Vitamin D formed profusely in the skin upon
exposure to sunlight, as well as from dietary sources, exhibits an immunomodulatory effect …

The main role of vitamin D is to control mineral homeostasis. However, recent studies
suggested the existence of a number of extraskeletal effects. Among the latter, preclinical
studies provided consistent data on the involvement of vitamin D in innate and adaptive
immunity and autoimmunity. Molecular biology studies showed that both vitamin D receptor
and vitamin D enzymatic complexes are expressed in a large number of cells and tissues
unrelated to mineral homeostasis. In contrast, only a few randomized clinical trials in …