Can I Take Calcium and Magnesium Supplements if I'm Taking Coumadin?

Especially if you are older, you may take supplements of calcium, magnesium or both to help make up for deficiencies of these minerals in your body. These two most common body minerals help all of your body systems work correctly. If you have cardiovascular problems and your doctor fears you may develop blood clots that can cause strokes, she may prescribe Coumadin. This medicine, known by the generic name warfarin, helps decrease the likelihood of dangerous blood clots forming in your blood vessels. Because Coumadin works to help a potentially serious health problem, you should consult your practitioner before you combine it with any other medicine or supplement, including calcium and magnesium.


Coumadin is a brand name in the United States for a medication called warfarin. It is one of several medicines doctors prescribe to thin your blood. You may need this anticoagulant if your blood has a high potential for forming dangerous clots. For example, if you have had a heart attack or open-heart surgery, you may develop a condition known as atrial fibrillation. This means part of your heart is not pumping effectively, which allows your blood to pool in your heart. Blood can get too thick in this circumstance, which can lead to clots. Clots can go to your brain where they can cause strokes. They also can cause blockages in your blood vessels and other serious health problems. Taking Coumadin makes the blood thinner and less likely to clot dangerously.


Your body, especially your bones and teeth, need calcium for strength. All other areas of your body also need daily doses of calcium. If you do not get enough calcium in your food, you may need to take a calcium supplement. Among its many functions, calcium can affect the way your heart beats. If you have cardiovascular problems such as high blood pressure, your doctor may prescribe a type of anti-hypertensive called a calcium channel blocker. This medicine works to keep calcium from affecting your heart adversely.


You also need magnesium on a daily basis 4. It helps your muscles, heart and nervous system work properly. It also can affect how your body uses calcium and regulates the amount of calcium in your system.

Interactions Between Coumadin and Calcium

Because calcium can affect your heart’s normal function, you should not take it while you take Coumadin unless your medical practitioner specifically recommends it. Your doctor keeps a close watch on how Coumadin affects you, especially in the early period of your Coumadin use. He may adjust your dose of Coumadin frequently until you do not need it anymore or until your heart condition has stabilized. Adding calcium on top of Coumadin can alter the way the latter works. Ask your doctor whether you can keep taking calcium and get specific information about his recommended dosage of the mineral if he approves it.

Interactions Between Coumadin and Magnesium

Magnesium may affect Coumadin in two ways. Magnesium helps your heart function properly, so it may help or hinder the Coumadin introduced into your body. Only your doctor can advise you about that. Another function that magnesium has can prove quite dangerous to someone taking Coumadin, however. Most of the Coumadin you take binds with blood protein and becomes inert, leaving only approximately 1 percent of the drug active in your bloodstream. Magnesium supplements have the potential to prevent some of the Coumadin from binding with this protein, meaning more than the expected dose of the drug remains active. This potential tendency can thin your blood too much, which can make you bruise easily or bleed excessively and dangerously if you become injured. Do not take a magnesium supplement without your physician’s permission.