PTH and chronic kidney disease: At that time, blood chemistries revealed a high parathyroid hormone (PTH: 364.5 pg/mL; normal range: 15-65 pg/mL) with an elevated phosphorous level (PO43-: 7 mg/dL; normal range: 2.7-4.5 mg/dL) and a normal ionized calcium (Ca2+: 4.3 mg/dL; normal range: 4.2-5.2 mg/dL) (Table 1) suggestive of secondary hyperparathyroidism likely due to chronic renal failure.