PTH and hypercalcemia disease: Subsequent laboratory testing for hypercalcemia revealed a low serum parathyroid hormone (PTH) level (7.2 pg/mL), a normal parathyroid hormone related peptide level (0.6 pg/mL), a low 25-hydroxyvitamin D level (21.80 ng/mL), an elevated 1,25-dihydroxyvitamin D3 (69 pg/mL), and elevated angiotensin-converting enzyme (141 units/L) (Table 1).