The role of the liver in the metabolism of vitamin D

G. Ponchon; H. F. Deluca

doi:10.1172/JCI106093

Published July 1, 1969 - More info

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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.