Anti-Rachitic Activity of Vitamin-D 3 -Precursors in the Rat

Summary

1. 7-hydroxy-cholesterol when given subcutaneously to rats, that are subsequently exposed to ultra-violet irradiation has a higher anti-rachitic effect than 7-de-hydrocholesterol injected into rats under identical conditions. 2. 7-keto-cholesterol when given subcutaneously to rats that are subsequently exposed to ultra-violet irradiation has equal or higher-anti-rachitic effect than 7-dehydro-cholesterol. 3. The per os introduction of 7-keto-cholesterol, 7-hydroxy-cholesterol and 7-dehydro-cholesterol into rats subsequently irradiated produces a lesser anti-rachitic effect than the subcutaneous injection of similar amounts of the sterols under otherwise identical conditions. Activated 7-dehydro-cholesterol forming an exception as shown in a previous report.