Here we report the use of newly developed and established techniques for the determination of plasma levels of a broad spectrum of vitamin D3 metabolites, including vitamin D3 and 250HD3-lactone, in normal humans, chronic renal failure patients, and anephric subjects. The methodology described consisted of methanol-methylene chloride extraction, Lipidex-5000 chromatography with stepwise gradient elution, normal-phase HPLC with concave gradient elution, and sensitive ligand-binding assays. The results of the study strongly suggest an extrarenal source(s) for 24,25(OH)2D3 and 25,26(OH)2D3 and indicate that both 25OHD3-lactone and 1,25(OH)2D3 may be produced solely in the kidney of the human. Significant reductions or nondetectable plasma levels of vitamin D3 in the renal disease patients may reflect abnormalities in the hepatobiliary-intestinal and/or cutaneous metabolism of vitamin D.
|Original language||English (US)|
|Number of pages||13|
|Journal||The Journal of Laboratory and Clinical Medicine|
|State||Published - Oct 1981|
ASJC Scopus subject areas
- Pathology and Forensic Medicine