Quantitation of the main metabolites of vitamin D in a single serum sample. II. Determination by UV-absorption and competitive protein binding assays.
The present report, together with extraction, separation and purification procedures described previously [1], constitutes a sensitive method for determination of vitamin D and its main metabolites in 2 ml of human serum. By omitting vitamin D itself, 25-OHD, 24,25-(OH)2D, 25,26-(OH)2D and 1,25-(OH)2D could be determined in less than 0.5 ml serum. The quantitation methods described have detection limits of 1.8 pmol for vitamin D, 20 fmol for 25-OHD, 24,25-(OH)2D and 25,26-(OH)2D, and 1 fmol for 1,25-(OH)2D.
D000818:Animals; D001667:Binding, Competitive; D002645:Chickens; D006801:Humans; D011869:Radioligand Assay / Q000379:methods; D014807:Vitamin D / Q000097:blood* / Q000302:isolation & purification
D014807:Vitamin D