The in vitro metabolism of 25-hydroxycholecalciferol by pig kidney: effect of low dietary levels of calcium and phosphorus

Abstract
1. Homogenates of pig kidney incubated in vitro convert 25-hydroxycholecalciferol to the dihydroxy-metabolites almost as efficiently as homogenates of chick kidney under similar conditions.2. The cortex of the kidney carries out this conversion more efficiently than does the medulla.3. Kidneys from pigs given low calcium or low phosphorus diets produce about 40 % more 1,25-dihydroxy cholecalciferol than those from pigs given diets containing normal levels of Ca and P.