[Vitamin D3 metabolism in the liver of pregnant rats].

The exchange of vitamin D3 in the liver of pregnant rats has been studied. Incorporation of (3H)-vitamin D3 into the liver of pregnant rats on the 13th and 21st day of pregnancy made up 85% and 90% respectively of the intensity of absorption of the summary label by controlled animals. It is found that the period of exchange of (3H)-cholecalciferol in these animals increases with prolongation of pregnancy. The 25-hydroxylation of vitamin D3 in the liver of rats on the 13th and 21st day of pregnancy significantly decreases and makes up 30% and 50% of its hydroxylation in the nonpregnant rats.