Fig. 1

a Parathyroid hormone (PTH), serum calcium, serum phosphate, and calciuria time course. Time 0 is defined as the day of parathyroidectomy (PTX). The dashed lines and colors show the lower and upper limits of parathyroid hormone (15–65 ng/L) in orange, albumin-corrected serum calcium (2.19–2.59 mmol/L) in blue, serum phosphate (0.87–1.45 mmol/L) in green, and calcium-to-creatinine molar ratio in urine (0.1–0.5) in yellow. Parathyroid hormone, calcium, and calciuria are dramatically increased at baseline, and phosphate is low. Vitamin D₃ (cholecalciferol) was started at week −1. Calcium therapy was conducted orally (2 g/day for weeks 0–19, then reduced to 1 g/day). Calcitriol 0.5 μg/day was given from weeks 0 to 19, then reduced to 0.25 μg/day and stopped at week 25. The capital letters and arrows indicate the time points at which imaging (Fig. 2a–d) and biopsies, respectively, were performed. b Alkaline phosphatase (AP; total activity) and bone-specific alkaline phosphatase mass time course. The dashed lines and colors show the lower and upper limits of alkaline phosphatase (35–104 U/L) in bright purple and bone-specific alkaline phosphatase (postmenopausal; 6–26 μg/L) in dark purple. Alkaline phosphatase was high before parathyroidectomy (reflecting high bone turnover resulting from hyperparathyroidism) and further increased (reflecting increased bone formation [hungry bone syndrome]) after parathyroidectomy