Biological Activity of 25-Hydroxyergocalciferol in Rats

Abstract
25-Hydroxyergocalciferol is 1.5 times more effective than either vitamin D2 or D3 in curing rickets in rats (60 units antirachitic activity per microgram). It is effective in inducing intestinal calcium transport and mobilization of bone mineral in rats and acts much more rapidly in these two systems than does vitamin D2.