Renal Phosphaturic Response to Parathyroid Hormone Administration and Dietary Intake of Phosphorus in Man

Abstract

The effect of a change in phosphorus content of the diet and afternoon measurement of urinary phosphorus excretion rates in response to a standard dose of parathyroid hormone (PTH) has been studied in 6 normal subjects, 4 patients with hypoparathyroidism, 1 patient with pseudohypoparathyroidism, and 1 patient with vitamin Dresistant rickets. The use of afternoon collection periods reduced the effect of diurnal variation on basal phosphorus excretion rates in all subjects. A low phosphorus diet further reduced this variation and produced a more easily demonstrable effect of PTH on phosphorus excretion. The low phosphorus diet and afternoon collection periods increase the ability of PTH-induced phosphaturia to discriminate between patients with hypoparathyroid disorders and normal subjects.