[Disturbances of calcium metabolism and vitamin D supplementation in sarcoidosis - two-way street].

The role of vitamin D in the human body is not limited only to the regulation of calcium metabolism and secondary to the impact on bones. Recent studies have shown the influence of vitamin D level on muscles, on the risk of cancer, diabetes, hypertension and pulmonary diseases, including granulomatous diseases. Sarcoidosis is a granulomatous disease of unknown etiology. Hypercalcemia in the course of the disease occurs in up to 10% of cases in the consequence of autonomous overproduction of 1,25-dihydroxyvitamin D by macrophages of sarcoid granulomas. Hypercalciuria occurs 3-fold more frequent. On the other hand, treatment with corticosteroids increases the risk of osteoporosis. Vitamin D intake is recommended for prevention of osteoporosis. Such management, in sarcoidosis patients, is not so clear because of risk of hypercalcemia. Vitamin D supplementation, according to current recommendations for general population, is based solely on 25-hydroxyvitamin D level testing. This seems to be not safe in the group of sarcoidosis patients. This article discusses the role of vitamin D in sarcoidosis patients and current opinion on vitamin D supplementation in this group.