PTH and Hypercalcemia: After admission, the biochemical assays revealed hypercalcaemia (2.76 mmol/L), hypophosphatemia (0.70 mmol/L), elevated PTH levels (134.60 pg/mL), reduced 25-hydroxyvitamin D3 levels (15.2 ng/mL; normal range 20–32) and normal levels of 24-hour urinary calcium (3.64 mmol/24 h).