Plasma 1,25(OH)2 vitamin d measured by radioimmunoassay and cytosol radioreceptor assay in normal subjects and patients with primary hyperparathyroidism and renal failure

M. Peacock, G. A. Taylor, Wendy Brown

Research output: Contribution to journalArticle

26 Scopus citations


Antibodies to 1α,25-dihydroxy vitamin D3 25-hemisuccinate linked to albumin were produced and an immunoassay for 1,25-dihydroxy vitamin D developed. Plasma 1,25-dihydroxy vitamin D concentrations were compared using an immunoassay and cytosol radioreceptor assay. Both assays gave comparable results but the immunoassay was more reproducible, slightly more sensitive and had a lower detection limit. Using the immunoassay the plasma 1,25-dihydroxy vitamin D was 110.5 pmol/l (S.D. 29.4) in normal subjects; there was no difference between males and premenopausal females. It was negatively related to plasma phosphate. In renal failure and primary hyperparathyroidism plasma 1,25(OH)2D was positively related to radiocalcium absorption. Following 1 and 2 μg of 1,25-dihydroxy vitamin D3 given orally the peak plasma concentration occurs within 12 h.

Original languageEnglish (US)
Pages (from-to)93-101
Number of pages9
JournalClinica Chimica Acta
Issue number1
StatePublished - Feb 14 1980


ASJC Scopus subject areas

  • Biochemistry
  • Clinical Biochemistry
  • Biochemistry, medical

Cite this