that vitamin k1 enhances the benzo ( a ) pyrene effect while warfarin and vitamin k deficiency inhibit benzo ( a ) pyrene tumorigenesis indicates that vitamin k1 , vitamin k deprivation , or possibly blockade of its metabolic cycle also modulates benzo ( a ) pyrene metabolism in vivo but by a mechanism or at a site different from the vitamin k3 effect .
C0042878
vitamin k
C0025270
vitamin k3