PTH and hypophosphatemia: At baseline, the patient demonstrated persistent hypophosphatemia (2.8 mg/dL; reference 2.5–5.5 mg/dL) with normal calcium, elevated alkaline phosphatase (137 U/L; 38–126 U/L), and increased parathyroid hormone (97.1 pg/mL; 18.5–88 pg/mL), consistent with secondary hyperparathyroidism.