Vitamin K was discovered by a Danish chemist named Henrik Dam. He won the 1943 Nobel Prize in Physiology or Medicine for discovering its key role in the coagulation of blood. Since that time, Vitamin K's role in other physiologic functions has become known. One of the most important is its role in controlling where calcium goes in the body.
Without Vitamin K, there would be a loss of blood when a person bleeds, which can lead to unconsciousness or even death. Vitamin K can be found in green vegetables, such as spinach, lettuce, broccoli or cabbage.