Respective roles of 25 hydroxy-vitamin D, PTH, phosphate and renal function for the 1-alpha-hydroxylase activity in primary hyperparathyroidism
Frølich, A.; Nielsen, B.F.; Transbøl, I.
Mineral and Electrolyte Metabolism 16(4): 210-215
1990
ISSN/ISBN: 0378-0392 PMID: 2277605 Document Number: 367386
Forty-three women (mean age 67 years, range 34-84 years) with primary hyperparathyroidism were investigated in an effort to examine the regulation of the 1-alpha-hydroxylase. This enzyme catalyzes the 1-hydroxylation of 25-hydroxy-vitamin D [25(OH)vit D] to 1,25-dihydroxy-vitamin D [1,25(OH)2vit D]. Serum 25(OH)vit D, 1,25(OH)2vit D, PTH, ionized calcium, phosphate and the 24-hour clearance of creatinine were measured. Different linear regression models were calculated with 1,25(OH)2vit D as the dependent variable. 25(OH)vit D was found to be definitely important for the regulation. The role of PTH for the 1,25(OH)2vit D production was discussed. Both renal function and phosphate concentration were found to influence the 1-alpha-hydroxylation.