Effect of Sunlight Exposure on Circulating 1,25-Dihydroxyvitamin D in Hemodialyzed Patients and of Exogenous Parathyroid Hormone in Anephric Patients

Autor: O H, Sørensen, B, Lund, J D, Thode, T L, Storm, M, Brahm, M, Friedberg, S N, Holmegaard
Rok vydání: 2009
Předmět:
Zdroj: Acta Medica Scandinavica. 219:215-219
ISSN: 0001-6101
DOI: 10.1111/j.0954-6820.1986.tb03301.x
Popis: Sunshine exposure increased the serum concentration of 25-hydroxyvitamin D (25-OHD) in 9 hemodialyzed patients. Mean 1,25-dihydroxyvitamin D (1,25-(OH)2D) was unchanged, but in two patients with low initial 25-OHD values this increase was accompanied by a rise in circulating 1,25-(OH)2D, although not to normal levels. One hemodialyzed patient developed liver insufficiency with a resultant reduction of serum 25-OHD concentration accompanied by a decrease in serum 1,25-(OH)2D concentration. The results indicate that the circulating levels of 1,25-(OH)2D in patients with end-stage renal failure are to some extent regulated by the serum 25-OHD concentrations. Injection of parathyroid hormone (PTH) induced minor increases in serum concentrations of 1,25-(OH)2D in patients with end-stage renal failure and even in anephric patients, suggesting the existence of an extrarenal PTH-sensitive 1-alpha-hydroxylase. However, the enzyme was stimulated by supraphysiological concentrations of PTH, and therefore not necessarily of importance in the normal regulation of calcium metabolism.
Databáze: OpenAIRE