Vitamin K is a dietary nutrient essential for the normal biosynthesis of factors that are required for blood clotting. It has also been shown to inhibit cell growth. Vitamin K1 2,3-epoxide is the inactive metabolite of vitamin K1. During clotting, vitamin K1 is converted to this epoxide form and then rapidly reduced back to the vitamin by a microsomal epoxide reductase. This is referred to as the vitamin K epoxide cycle. Certain anticoagulants target clotting factor synthesis by inhibiting the recycling of vitamin K1 from the inactive epoxide.
