Coumadin, known generically as warfarin, is a blood thinner mainly prescribed if you have a history or risk for blood clots. Pulmonary embolism and deep vein thrombosis are two dangerous types of clots that Coumadin helps to treat and prevent. Coumadin may also be prescribed if you have an irregular heart beat, a replacement heart valve or history of a heart attack. Certain vitamins interact with Coumadin, so it is important to exercise caution when choosing a multivitamin.
Vitamin K
Vitamin K is a natural coagulant, meaning it helps blood to clot. Because Coumadin is an anticoagulant, it is important to watch your intake of vitamin K while on blood thinners. Vitamin K is found mainly in dark, leafy green vegetables like spinach and collard greens.
Check the label on your multivitamin to see if it contains vitamin K. The Centrum brand of multivitamins, for instance, may or may not contain vitamin K. Centrum Forte and Centrum Over 50 do contain vitamin K. If you choose a multivitamin that has vitamin K, it is important to take the same amount, at the same time every day while on Coumadin.
Vitamin E
Vitamin E helps thin the blood, just as Coumadin does. It is best to avoid large supplemental doses on vitamin E while on Coumadin, since they have similar anticoagulation effects. If you choose a multivitamin that contains vitamin E, opt for lower doses closer to 25 IUs. Avoid taking fish oil supplements or vitamin E supplements unless instructed by your doctor.
Cranberry Juice Extract
Certain multivitamins may contain additional nutrients like cranberry extract. Although cranberry provides beneficial antioxidants, it may be dangerous while you are taking Coumadin. Avoid supplements that contain cranberry extract while on this medication.
Consistent Intake for Consistent Labs
Your doctor will adjust your Coumadin dosage based on your individual needs. Regular blood tests are used to determine your PT-INR level. PT, prothrombin time, measures the time it takes for your blood to clot. INR is the International Normalized Ratio, a standard comparison of your prothrombin time. These labs indicate how well the medication is working for you.
Being consistent with your diet and supplement routine is very important. Consistency helps your doctor predict the correct dosage to fit your usual habits. Take Coumadin at the same time each day and avoid alcohol while on this medication. If you take herbal supplements, do not stop taking them without first discussing this with your doctor.
