PTH and secondary hyperparathyroidism: Secondary hyperparathyroidism (SHPT) is a common complication of chronic kidney disease (CKD) characterized by the hypersecretion of parathyroid hormone (PTH) and the parathyroid gland hyperplasia stimulated by CKD-related chronic hyperphosphatemia, hypocalcemia, and 1,25-dihydroxyvitamin D (1,25(OH)2D) deficiency (1), affecting nearly 90% of those with end-stage kidney disease (ESKD) receiving chronic renal replacement therapy (RRT) (2).