Measurement of 25-Hydroxycholecalciferol in the Bovine

Abstract

Bovine plasma 25-hydroxycholecalciferol was estimated by rapid protein binding assay. Serum-binding proteins in the assay were from rats deficient in vitamin D and from normal rats; no differences existed in standard curves. 25-Hydroxycholecalciferol in 8 cows averaged 45.5 .+-. 12.2 ng/ml of plasma. Results from the rapid protein binding assay compared favorably (> 10% deviation) with values from a 25-hydroxycholecalciferol assay involving high pressure liquid chromatography.