Altered vitamin D metabolism and bone remodelling in patients with medullary thyroid carcinoma and hypercalcitoninemia

Abstract Fourteen patients with medullary carcinoma of the thyroid (MCT) and hypercalcitoninemia were studied. Serum concentrations of calcium, phosphorus and iPTH (C-terminal) were normal. Serum 1,25-dihydroxyvitamin D (1,25-(OH) 2 D) levels were increased (p in vivo tetracycline double-labelling were performed in patients and controls. The patients showed a normal trabecular bone volume. The mean size of the cortical osteocytic lacunae was increased (p 2 D.