A fat soluble vitamin, good sources of vitamin K include green leafy vegetables, such as collard greens, spinach and kale, milk, eggs, liver and some meats. This vitamin is also made in the intestine, so vitamin K deficiency is rare, unless there are any underlying assimilation problems. Discovered in Denmark, vitamin K is named after the Danish work for coagulation – koagulation.
What is Vitamin K?
Vitamin K helps with normal blood clotting and is required for the synthesis of prothrombin and other proteins involved in blood coagulation. Vitamin K also helps prothrombin convert to thrombin with the help of potassium and calcium. Coumarin, from sweet clover, acts as an anticoagulant by competing with vitamin K, and is used medically as an oral anticoagulant to decrease prothrombin levels. Taking salicylates, including aspirin, increases the body’s need for vitamin K.
Vitamin K Sources
Vitamin K is found both in plant and animal foods. The best vitamin K sources are green leafy vegetables, most green plants, alfafa sprouts and kelp. Black strap molasses also contains good levels of vitamin K along with most polyunsaturated oils. Vitamin K is also found in milk, eggs, yogurt and meat. However, the best source is that made by the body in the intestine. Intestinal bacteria in the gut are important for the production of many important nutrients, so having a healthy gut is vital to good health. Avoiding antibiotics as much as possible, taking probiotic supplements, and eating live natural yogurt are all healthy options.
Foods Rich in Vitamin K
Kale contains the highest levels of vitamin K. One cup of frozen, cooked, boiled and drained kale contains 1,147 ug of vitamin K. Next in line are collard greens with 1,057 ug per cup of cooked and boiled greens. Third on the list is spinach with one cup yielding 1,027 ug. Other vegetables in the top 10 include: turnip greens with 851 ug, beet greens with 697 ug, mustard greens with 419 ug, Brussels sprouts with 300 ug, broccoli with 220 ug and onions with 207 ug.
Disclaimer:The information contained in this article is for educational purposes only and should not be used for diagnosis or to guide treatment without the opinion of a health professional. Any reader who is concerned about his or her health should contact a doctor for advice.
References:
United States Department of Agriculture. Nutrient Data Laboratory (accessed January 18, 2011).
Elson M Haas, Staying Healthy with Nutrition, Celestial Arts 2006.
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