25-Hydroxyvitamin D

Vitamin D is a fat-soluble steroid prohormone mainly produced photochemically in the skin from 7-dehydrocholesterol. Two forms of vitamin D are biologically relevant – vitamin D3 (Cholecalciferol) and vitamin D2 (Ergocalciferol). Epidemiological studies have shown a high global prevalence of vitamin D insufficiency and deficiency. The measurement of vitamin D status provides opportunities for preventive and therapeutic interventions. Vitamin D deficiency is a cause of secondary hyperparathyroidism and diseases resulting in impaired bone metabolism (like rickets, osteoporosis, osteomalacia). Reduced 25-OH vitamin D concentrations in blood (vitamin D insufficiency) have been associated with an increasing risk of many chronic diseases, including common cancers, autoimmune or infectious diseases or cardiovascular problems.