Ivan Tkáč, Miriam Kozárová
Circulating form of vitamin D, 25-hydroxyvitamin D [25(OH)D], is a modifiable quantitative trait associated with several extraosseal diseases including metabolic syndrome, diabetes mellitus type 1 and 2, cardiovascular diseases, sclerosis multiplex, some malignant diseases (namely colorectal carcinoma, breast and prostate carcinoma) and disorders of immune system. On the basis of epidemiological studies it is possible to assume that low levels of 25(OH)D play a role in pathogenesis of endothelial dysfunction, insulin resistance, metabolic syndrome and type 2 diabetes (DM2). Several clinical studies even proved that the level of 25(OH)D was related to metabolic control of DM2 by the influence on insulin resistance and secretion function of pancreas β cells. Supplementation by vitamin D in patients with DM2 could lead to potential long-term favourable effects, reduction of severe complications and improvement of quality of life while fulfilling the conditions of right indication.