Vitamin D deficiency: a pandemic of the 21st century. Problems of standardization of diagnosis of vitamin D deficiency

Vitamin D deficiency is a noninfectious pandemic of the 21st century. Vitamin D, apart from its role in phosphorus-calcium metabolism, is vital for functioning of all organs and systems, and its deficiency is a risk factor of developing aging-associated extraskeletal diseases. Vitamin D deficiency is a multifactor process related to a decreased synthesis of endogenous cholecalcipherol, insufficient intake of exogenous vitamin D and its disordered metabolism. Improvement of the effectiveness of therapeutic and preventive measures for management of vitamin D deficiency is impossible without accurate laboratory diagnosis. Immunochemical methods (radioactive, enzymatic and chemiluminescent) overestimate the 25(ОН)D levels, a benchmark test for vitamin D status assessment is a high performance liquid chromatography tandem–mass spectrometry. In order to reduce the risk of socially significant diseases the adequate 25(ОН)D levels should be not less than 40 ng/mL (100 nmol/L). Key words: vitamin D, vitamin D deficiency, liquid chromatography tandem–mass spectrometry