In people with a reduced glomerular filtration rate, the serumparathyroid hormone level is often secondarily elevated as aresult of reduced serum levels of calcium and 1,25-dihydroxyvitaminD3 and an increased serum phosphate level (referred to as secondaryhyperparathyroidism). The mean parathyroid hormone level isincreased by a factor of more than seven in patients who arereceiving hemodialysis.1 In addition to the well-described associatedmetabolic bone disease, secondary hyperparathyroidism and itstreatments may play a role in the high rates of death and cardiovasculardisease among patients with end-stage renal disease.2,3