Vitamin K was first identified by a Danish scientist in 1929, who noticed that chicks fed diets lacking in a certain substance were slow to form blood clots. He named the substance 'Vitamin K' for the Danish word meaning 'coagulation.' It regulates coagulation by helping to produce a protein used in blood clotting. It also helps make a protein that regulates blood calcium levels. Some research on tumor cells removed from the body show that Vitamin K may inhibit the growth of several forms of cancer. Vitamin K is found in foods such as green leafy vegetables, cabbage, cauliflower, and soybeans. Most of the body's supply, however, can be obtained internally. The vitamin is produced in the intestines, where bacteria exist and generate it from various food nutrients. Vitamin K deficiency in the U-S is rare, but newborn babies sometimes don't get enough of the vitamin because their intestinal bacteria may not yet have developed sufficiently. Adults who chronically use antibiotics or have liver disease also may have inhibited growth of bacteria in the intestines. For more information about this vitamin, contact a healthcare professional.