Phytomenadione, also known as vitamin K1 or phylloquinone, is a vitamin found in food and used as a dietary supplement. As a supplement it is used to treat certain bleeding disorders.This includes in warfarin overdose, vitamin K deficiency, and obstructive jaundice. It is also recommended to prevent and treat hemorrhagic disease of the newborn. Use is typically recommended by mouth or injection under the skin.Use by injection into a vein or muscle is recommended only when other routes are not possible. When given by injection benefits are seen within two hours.