Category: vitamin
Aliases: Vitamin K1, Phytonadione
Cofactor for γ-glutamyl carboxylase, which γ-carboxylates glutamate residues on vitamin-K-dependent proteins (coagulation factors II, VII, IX, X; protein C/S; osteocalcin; matrix Gla protein). The reduced (hydroquinone) form is oxidised during carboxylation and recycled by vitamin-K epoxide reductase (VKOR, blocked by warfarin). K1 is predominantly hepatic → clotting factors.
PO: 1.5h, IV: 1.5h