Certain medications require you to make modifications to your diet to make them more effective or less effective. If you take Coumadin, your doctor may have instructed you to adjust your intake of foods high in vitamin K. Vitamin K in food can decrease the effectiveness of Coumadin, requiring an adjustment in dosage. There are specific guidelines you can follow to help manage both your Coumadin regimen and diet.
Uses of Coumadin
Coumadin is prescribed to people who have a high risk of developing blood clots. It can prevent you from having a heart attack or stroke, and can help reduce your risk of forming blood clots in your veins and arteries.
Coumadin Function
Blood clotting is a complex chemical reaction that requires several steps to occur. Vitamin K is necessary for the proper functioning of several proteins required for proper blood clotting. Coumadin helps to prevent your blood from clotting by reducing vitamin K activity, increasing the length of time it takes for your blood to clot. When you take Coumadin, you need to have your international normalized ratio, or INR, and prothrombin time, or PT, checked monthly to assess how quickly your blood clots. Your doctor adjusts your Coumadin dose based on these measurements.
Vitamin K and Coumadin
If you consume a diet high in vitamin K, your blood will clot faster, decreasing the effectiveness of the Coumadin. If you consume too little vitamin K in between lab checks, you will increase the effectiveness of the Coumadin, which can lead to uncontrollable bleeding. To manage Coumadin and blood clotting, you need to eat a consistent amount of vitamin K each day.
Food Sources of Vitamin K
Green leafy vegetables are your primary sources of vitamin K. Kale contains the highest amount with 547 mcg in a 1-cup serving of chopped raw kale. A 1-cup serving of raw Swiss chard contains 299 mcg, and the same size serving of raw spinach contains 145 mcg. Broccoli is also high in vitamin K with 220 mcg in a 1-cup serving of chopped, cooked broccoli. Other greens high in vitamin K include parsley, green leaf lettuce and watercress. Some oils also contain vitamin K, including soy oil, canola oil and olive oil.
Coumadin and Diet
To meet your daily value needs, you need 80 mcg of vitamin K a day. To help you be consistent with your vitamin K intake, the National Institutes of Health suggests you limit your intake of foods high in vitamin K, foods with more than 160 mcg of vitamin K per serving, to no more than one serving a day. You should also limit your intake of moderately high vitamin K foods, foods with 56 to 152 mcg of vitamin K per serving, to no more than three servings a day.
