Vitamin K is important in coagulating (clotting) blood. People who take warfarin or its trade name Coumadin, a true blood thinner (anti-coagulant), have to be careful about their vitamin K consumption. Since warfarin antagoinizes the action of vitamin K, its effect can be overcome by increasing the amount of vitamin K available. Thus, people who take warfarin for the any of the medical reasons it is prescribed, must pay attention to foods that will affect their dosing of warfarin. When vitamin K rich foods are consumed, there is an increased liklihood that an adjustement of the warfarin dose will be required. It is best to consume foods with little vitamin K, with as much constancy in one's diet as possible, to minimize the typical variation in anti-coagulation status (usually measured by a blood test referred to as an INR).
Low Vitamin K Foods
Moderate Vit K Foods
High Vitamin K Foods
Corn, Peanut, Sesame, Sunflower, Safflower Oil
Canola, Soybean Oil
Beans (from a pod)
Potato (a starch)
The following foods, which includes much of what one might eat on a daily basis, are generally low in vitamin K.
- Beverages such as coffee, cola, fruit juice, tea and milk are all low in vitamin K.
- Most grains are low in vitamin K (e.g. cereal, flour, oatmeal, rice, pasta, bread).
- Eggs and dairy are low in vitamin K, including sour cream and yogurt.
- Fruits tend to be low in vitamin K (e.g. apple, banana, berries, melons, citrus, peaches).
- Meat, fish and poultry are low in vitamin K. Liver would be the notable exception.
- Honey, Gelatin and Peanut Butter are low vitamin K foods.
- Booth SL, Sadowski JA, Weihrauch JL, Ferland G. Vitamin K (phylloquinone) content of foods: a provisional table. Jouranl of Food Composition and Analysis. 1993; 6:109-120.
- Booth SL, Sadowski JA, Pennington JAT. Phylloquinone (vitamin K) content of foods in the US Food and Drug Administration's total diet study. Journal of Agriculture and Food Chemistry. 1995; 43: 1574-1579.
- Ferland G, MacDonald DL, Sadowski, JA. Development of a diet low in Vitamin K (phylloquinone). Journal of the American Dietetic Association. 1992; 92: 593-597.