Radiographic Demonstration of Protection by Vitamin D Against Metaphyseal Decalcification in Adult Rats on High Calcium—Low Phosphorus Diet

Abstract

Adult rats have been kept on the no. 2965 rachitogenic diet of Steenbock and Black for a period of 52 weeks. By means of a special radiographic technique, as well as by bone ash determinations, it was possible to show that considerable decalcification of the skeleton occurred. This condition was markedly improved, although not completely corrected, by moderate doses of vitamin D administered during the last 18 weeks of the experiment. It has also been shown that the structures of the proximal end of the tibia, even in the adult animal, are especially sensitive to changes in mineral metabolism which affect calcification. Adult rats deprived of vitamin D, develop a rather typical decalcified metaphyseal space which may be recalcified by 2.0 international units of vitamin D per day, even on this restricted basal ration. Addition of whole dried yeast and carotene improved the general physical condition of the animals but failed to result in any demonstrable change in the bones.