Abstract

The metabolism of vitamin D3 has been studied after intravenous injection of 10 IU of [1,2-3H]-vitamin D3 to vitamin D-deficient rats. The disappearance of the radioactivity from the plasma follows a very peculiar pattern characterized by an early rapid disappearance followed by a rebound of radioactivity before assuming still a third rather slow disappearance rate. The “rebound” phenomenon is concomitant with a rapid release of the radioactivity from the liver and is accounted for by the appearance of 25-hydroxycholecalciferol and other metabolites in the blood. It is postulated that the liver is the major site of transformation of vitamin D3 into 25-hydroxycholecalciferol.

Authors

G. Ponchon, H. F. Deluca

×

Other pages: