Vitamin K1, also known as phylloquinone or phytomenadione, is made by plants, and is found in highest amounts in green leafy vegetables because it is directly involved in photosynthesis. It may be thought of as the plant form of vitamin K. It is active as a vitamin in animals and performs the classic functions of vitamin K, including its activity in the production of blood-clotting proteins.
Vitamin K2 (menaquinone) includes several subtypes. The two most studied ones are menaquinone-4 (menatetrenone, MK-4) and menaquinone-7 (MK-7).