First discovered by Danish scientist Henrik Dam in 1935, vitamin K became known as the "blood clotting" vitamin, hence its full name "Koagulations vitamin." It is also essential for healthy bones. The Harvard School of Public Health estimates that only 25 percent of Americans get adequate amounts of vitamin K.
Types of Vitamin K
Vitamin K comes in three basic forms. K1, phylloquinone, is obtained from plants. K2, menaquinone, is produced in small amounts by bacteria in human intestines. K3 is a synthetic form not ordinarily used for humans.
Food Sources of Vitamin K
Green leafy vegetables, some cooking oils, and some fruits and vegetables contain vitamin K. Dark berries, avocados, prunes, and soybeans, canola and olive oils are good sources. Green vegetables such as kale, collard greens, broccoli, Brussels sprouts, cabbage, spinach, turnip greens, okra, and asparagus provide dietary vitamin K.
Vitamin K Deficiency
The recommended daily intake for vitamin K is 120 mcg for men, and 90 mcg for women. Low vitamin K is associated with low bone density. Lack of the vitamin may cause bleeding and bruising, inability for normal blood clotting, blood in the urine or stool and worsening of liver disease. Vitamin K deficiency may occur from an inadequate diet, disorders that make it difficult for the body to absorb fats, ingesting too much oil such as mineral oil, or some medicines.
Treatment of Vitamin K Deficiency
Depending upon the person's overall health, and the reason for the deficiency, dietary changes may be enough to correct a person's lack of vitamin K. Sometimes injections or oral supplements are used, or medication may be adjusted. If a person has severe liver disease transfusions may be given.
When Vitamin K Must Be Limited
People with too much blood clotting, such as those at severe risk for stroke, are often prescribed blood thinners such as warfarin, and they should have their vitamin K levels closely monitored. Less blood clotting is also desirable for conditions including deep vein thrombosis, pulmonary embolism and some irregular heart rhythms.
Vitamin K and Cancer
Vitamin K is a subject of continuing research for any anti-cancer properties. The American Cancer Society reports that there is no evidence yet that vitamin K is helpful in cancer treatment. In 2010, the Mayo Clinic reported results of an ongoing clinical trial using vitamin K in Non-Hodgkin's lymphoma patients. So far the results indicate that vitamin K can help reduce chemicals that contribute to inflammatory pathways helpful in stopping white cell death at the right time. If white cell death proceeds normally, the lymphoma would be slowed in its progression, and lymphoma may be prevented in those at risk.
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