PTH and Hypercalcemia: Laboratory studies showed hypercalcemia (albumin-corrected calcium 3.55 mmol/L), low phosphate (0.56 mmol/L; normal range 0.87–1.45 mmol/L), impaired renal function (creatinine 119 μmol/L, estimated glomerular filtration rate of 39 ml/minute), elevated AP (189 U/L), and a grossly elevated PTH level (1466 ng/L; normal range 15–65 ng/L) (Fig. 1a, b).