Phytonadione is a chemical compound that is commonly known as vitamin K1. It is a fat-soluble vitamin that plays an essential role in blood clotting and bone metabolism. However, in some cases, it may cause adverse effects like excessive bleeding or blood clots. In such cases, substitutes or synonyms for phytonadione may be used. Some of the alternatives for phytonadione include menadione, vitamin K2, and vitamin K3. Menadione is also known as vitamin K3 and is a synthetic form of vitamin K used as a dietary supplement. Vitamin K2 is another natural form of vitamin K found in some foods, while vitamin K3 is a synthetic form primarily used in animal feed.