Coagulopathy and Fat-Soluble Vitamins

To the Editor.— The recent report by Corrigan and Marcus describing potentiation of warfarin anticoagulation by vitamin E (230:1300, 1974) is consistent with some unpublished studies performed several years ago by Dr. H. M. Solomon and myself. We conducted preliminary studies of the effect of vitamins A, D, and E on vitamin K-dependent clotting factor activity as measured by the anticoagulant response to single doses of warfarin or dicumarol. Briefly, male rats were given warfarin before and after four days' treatment with one of the following: vitamin A acetate, 1,000-15,000 international units (IU); ergocalciferol, 404,000 IU; vitamin E, 0.7-70 IU. The Figure shows the distribution of percent of coagulation activity found 72 hours after warfarin administration in treated and control groups. Potentiation of anticoagulant effect in each vitamin-treated group is obvious. Data from each group were pooled since no dose-response effect was apparent. Subsequently, three healthy human volunteers were given