Sensitivity of the Parathyroid Hormone–1, 25-Dihydroxyvitamin D Axis to Variations in Calcium Intake in Patients with Primary Hyperparathyroidism

Abstract
Previous studies have demonstrated a spectrum of parathyroid responsivity to alterations in the extracellular calcium concentration in patients with primary hyperparathyroidism, but studies employing physiologic amounts of calcium have not, to our knowledge, been reported.