Moderate hypercalcemia Moderate hypercalcemia (serum calcium > 11.5 mg / dL [> 2.88 mmol / L] and < 18 mg / dL [< 4.51 mmol / L]) can be treated with isotonic saline and a loop diuretic as is done for mild hypercalcemia or, depending on its cause, with drugs that decrease bone resorption (usually bisphosphonates, calcitonin, or infrequently plicamycin or gallium nitrate), corticosteroids, or chloroquine.