Vitamin K is essentially a combination of molecules, with vitamins K1 and K2 appearing to be the most important. The principal form, phylloquinone, can be seen in green leafy veggies like collard greens, kale, and spinach, while menaquinones, the other form, can be seen in fermented meals and some animal products; bacteria residing inside the human body can also generate menaquinones. Every organ in the body, including the pancreas, liver, brain and heart, contains vitamin K and the vitamin breaks down fast and then is flushed out of the body through urine or stool. In contrast to other fat-soluble vitamins, vitamin k rarely reaches hazardous levels in the body, even at high consumption, because of the above process. Vitamin K aids in blood clotting and prevents excessive bleeding, but unlike several other vitamins, it is not commonly taken as a nutritional supplement.