We all need a good supply of vitamin K to stay healthy, but it’s important to remember that not all vitamin K is the same. In fact, vitamin K is actually a group of several related compounds, classified into two main types, K1 and K2. Vitamin K1 is often called the?plant form? of the vitamin, as it is found primarily in green leafy vegetables. Vitamin K2 (menaquinone) is the main storage form of the vitamin in animals, and is the most biologically active form in human physiology. While vitamin K is mostly known for its involvement in blood clotting, K2 also helps to activate the proteins that regulate where calcium ends up in the body. Out of thirteen different subtypes of vitamin K2 that have been identified, menaquinone-7 has shown great promise for promoting bone strength and cardiovascular health, thanks to its role in regulating calcium transport. Menaquinone-7 is found in many foods, including aged cheeses, liver and eggs, but the richest source by far is natto, a traditional Japanese food made from fermented soybeans. Swanson Ultra Maximum Strength Vitamin K2 is our highest potency K2 supplement ever, derived from natto made exclusively from non-GMO soybeans.