Biomaterial Database

Assay of plasma 25-hydroxy vitamin D. 1976

J F Morris, and M Peacock

A radio-competitive protein-binding assay for 25-hydroxy vitamin D3 (25-OHD3) is described using diluted plasma from patients with vitamin D deficient osteomalacia as the binding protein. The 25-OHD3 is extracted from plasma with ethanol and assayed directly without further purification. An incubation of two hours is used to give suitable binding. The lower detection limit of the assay is approximately 23 pg, the intra-assay coefficient of variation is 5.4% and the inter-assay variation 15%. Tth a mean of 26.9 mug/l. Levels of plasma 25-OHD3 are undetectable in patients with vitamin D deficient osteomalacia and greater than 110 mug/l in patients taking large doses of vitamin D2.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008722	Methods	A series of steps taken in order to conduct research.	Techniques,Methodological Studies,Methodological Study,Procedures,Studies, Methodological,Study, Methodological,Method,Procedure,Technique
D008832	Microchemistry	The development and use of techniques and equipment to study or perform chemical reactions, with small quantities of materials, frequently less than a milligram or a milliliter.
D010018	Osteomalacia	Disorder caused by an interruption of the mineralization of organic bone matrix leading to bone softening, bone pain, and weakness. It is the adult form of rickets resulting from disruption of VITAMIN D; PHOSPHORUS; or CALCIUM homeostasis.	Adult Rickets,Rickets, Adult
D011869	Radioligand Assay	Quantitative determination of receptor (binding) proteins in body fluids or tissue using radioactively labeled binding reagents (e.g., antibodies, intracellular receptors, plasma binders).	Protein-Binding Radioassay,Radioreceptor Assay,Assay, Radioligand,Assay, Radioreceptor,Assays, Radioligand,Assays, Radioreceptor,Protein Binding Radioassay,Protein-Binding Radioassays,Radioassay, Protein-Binding,Radioassays, Protein-Binding,Radioligand Assays,Radioreceptor Assays
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D006887	Hydroxycholecalciferols	Hydroxy analogs of vitamin D 3; (CHOLECALCIFEROL); including CALCIFEDIOL; CALCITRIOL; and 24,25-DIHYDROXYVITAMIN D 3.	Hydroxyvitamins D,Hydroxycholecalciferol
D001667	Binding, Competitive	The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.	Competitive Binding
D014808	Vitamin D Deficiency	A nutritional condition produced by a deficiency of VITAMIN D in the diet, insufficient production of vitamin D in the skin, inadequate absorption of vitamin D from the diet, or abnormal conversion of vitamin D to its bioactive metabolites. It is manifested clinically as RICKETS in children and OSTEOMALACIA in adults. (From Cecil Textbook of Medicine, 19th ed, p1406)	Deficiency, Vitamin D,Deficiencies, Vitamin D,Vitamin D Deficiencies