Observations on the different calcium metabolic patterns in sarcoidosis. A metabolic and kinetic study

Combined calcium balance and 47Ca turnover studies in sarcoidosis (4 patients) and vitamin D intoxication (1 patient) disclosed three different patterns of calcium metabolism. On patient with sarcoidosis had a normal metabolism of calcium, and two patients presented the usual pattern of intestinal hyperabsorption, hypercalcemia, and hypercalciuria. The fourth patient with sarcoidosis and the patient with vitamin D intoxication, both studied during spontaneous remissions, presented the third pattern. The main features here were hypercalcemia despite normal intestinal absorption of calcium, enlarged exchangeable calcium pool, accelerated accretion and resorption rates, hypercalciuria, and a distinctly negative calcium balance. This pattern of remission seems to represent a mobilization of extraosseous or metastatic calcifications, rather than a resorption of bone calcium.