Intestinal calcium absorption, serum phosphate, and parathyroid hormone in patients with chronic renal failure and osteodystrophy before and during hemodialysis.

In 34 patients with chronic renal failure (CRF), fractional 47calcium absorption (Fa47Ca) was measured by an external counting method. A significant correlation was found with impairment of renal function, as expressed by the creatinine clearance. There was also a significant correlation of Fa47Ca with the serum phosphate (SeP) level and of immunoreactive parathyroid hormone (iPTH) with renal function. When the relationship of both SeP and Fa47Ca with creatinine clearance was excluded, no partial correlation between SeP and Fa47Ca appeared to exist. A significant increase of Fa47Ca and serum Ca and a significant decrease of SeP and iPTH were found in 12 patients 2 to 15 months after they were put on intermittent hemodialysis. The possible influence of SeP on intestinal calcium absorption is discussed, and it is suggested that impairment of intestinal absorption of calcium is not a main factor in development of renal osteodystrophy.