What Is Vitamin K Needed For?

When you cut your finger, you expect it to stop bleeding. What if it didn't? Without vitamin K, your blood would not clot. Luckily, bacteria in your colon can make some of the vitamin K you need, and you can find the rest in certain foods. In addition to preventing you from bleeding to death, vitamin K plays other important roles in your health.

Coagulation

Discovered in 1935 by Danish scientist Henrik Dam, vitamin K was named after the German word for clotting, koagulation, according to the American Cancer Society. Your liver needs vitamin K to make blood-clotting factors that prevent abnormal bleeding. If you are at risk for forming blood clots that could block arteries, your doctor may prescribe a drug that inhibits the action of vitamin K.

Bone Health

Bone-building mechanisms in your body are dependent on vitamin K. A 2007 article in "Nutrition in Clinical Practice" reports on studies that show a correlation between vitamin K intake and bone mineral density. In the Nurses' Health Study, women who consumed the most vitamin K-rich foods over a 10-year period had a significantly lower risk of hip fracture than those with the lowest intake. The Framingham Heart Study had similar results: men and women who consumed at least 254 mcg of vitamin K daily had a much lower risk of hip fracture than those who took in the least.

Prevention of Cardiovascular Disease

Adequate vitamin K intake may prevent atherosclerosis, or hardening of your arteries, and subsequent heart attack or stroke. Although the exact mechanism is unknown, the vitamin may be responsible for the action of compounds that prevent calcification of blood vessels. Studies reviewed by the Linus Pauling Institute's Micronutrient Information Center are inconclusive, and more research is needed.

Adequate Intake

The Institute of Medicine's Food and Nutrition Board has set the recommended intake of vitamin K at 90 mcg daily for women and 120 mcg a day for men. Although you can make your own with the help of bacteria in your colon, you still need to eat food sources of the vitamin to get enough. Consume green leafy vegetables, such as parsley, kale, Swiss chard, leaf lettuce and broccoli. Canola oil and soybean oil are also good sources.

Other Considerations

Studies have investigated vitamin K's role in cancer prevention, but, according to the American Cancer Society, the evidence is not convincing. Ingestion of foods or supplements high in vitamin K are known to interact with the blood-thinning medication, warfarin. Eating foods with vitamin K is usually sufficient to meet the recommended daily amount. Most people do not need supplements, unless they are prescribed by a doctor.