Chronic Toxicity and Hypercalcemic Effects of Various Activated Sterols in the Albino Rat

Abstract

Summary

For the albino rat, medicated daily until death, crystalline vitamin D₃ is about 55%, and commercial dihydrotachysterol about 260% more toxic than crystalline vitamin D2 (based on the actual weights of the active principles). So far as vitamins D₂ and D₃ are concerned, the toxicities correlate very well with the hypercalcemic effects of the preparations. However, in the case of dihydrotachysterol the toxicity and ability to elevate serum calcium are not in that same proportion. In view of the difference in response of different species, these considerations do not necessarily apply to any species other than the albino rat.