What Foods Can Affect Coumadin Levels?

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Coumadin, a brand name of the drug warfarin, is a blood thinner given to prevent or slow the formation of plaque and clots in your blood vessels. Coumadin works by decreasing the effectiveness of vitamin K. The appropriate dose of Coumadin depends on the amount of vitamin K in your diet. Keep your dietary vitamin K consistent to avoid uncontrolled bleeding while on Coumadin.

About Coumadin

Coumadin is a blood thinner that is prescribed by your doctor if you are at high risk of developing blood clots due to a heart arrhythmia, injury or other disease. Coumadin works by inhibiting the action of vitamin K in the liver. Vitamin K is necessary for a process that prepares blood proteins so they are able to clot.

Diet on Coumadin

The level of your dietary intake of vitamin K can change the effectiveness of Coumadin. You should maintain your normal diet while on Coumadin to keep you vitamin K intake relatively constant. It is important to eat a consistent diet and know the levels of vitamin K in foods you eat and supplements you take.

Green Leafy Vegetables

The most abundant source of vitamin K in the diet is green leafy vegetables. Spinach, kale, broccoli and parsley are high in vitamin K. Green leaf lettuce, watercress and other lightly flavored green vegetables you may use in salads also contain significant amounts of vitamin K. Keep track of the number of salads and servings of green leafy vegetables you get each week and keep that number relatively constant while on Coumadin.

Vegetable Oils

Mayonnaise and vegetable oils also contain a small amount of vitamin K. Vegetable oils with vitamin K include olive, soybean and canola oil. Each 1 tbsp. oil contains approximately 1 to 10 percent of the vitamin K found in 1 cup of green leafy vegetables. Track how much mayonnaise and oil you use while you're on Coumadin, although varying your intake of oil and mayonnaise isn't as crucial as your intake of green vegetables.

When to See Your Doctor

High levels of Coumadin, especially with a low vitamin K intake, have the potential to cause severe bleeding, potentially resulting in death. Contact your doctor immediately if you experience unexplained pain or bruises, uncontrolled bleeding from a wound, nosebleed or bleeding from your gums, coughing up blood or coagulated blood that appears similar to coffee grounds, or if you find fresh or coagulated blood during urination or a bowel movement. You may also need to see your doctor if you have or plan to have any changes in your diet while on Coumadin.