Vitamins and Supplements

The foods you choose to eat can affect your heart health in many ways. It’s why so many cardiologists recommend a diet packed with fruits and vegetables, fish and whole grains, with limited unhealthy fats. In fact, your general nutrition plays a key role in helping to regulate your body weight; blood pressure, glucose and cholesterol levels; as well as inflammation and how your blood clots.

Certain vitamins and herbal supplements — for example, green tea, omega-3 fatty acids, soluble fiber, soy protein, certain antioxidants, Coenzyme Q10 and others — have also been shown to support cardiovascular health. On the flip side, high levels of vitamin E and C supplementation may be harmful for cardiovascular health. While the jury is still out, a recent study found calcium supplements may make a heart attack more likely.

It’s also important to know that some vitamins and dietary supplements can interfere with treatments, sometimes in very important and dangerous ways. Use this page to learn more about dietary supplements and questions to ask your health care team. 

Take Note

Even though vitamins and supplements can benefit overall health and provide essential nutrients, they can also interact with certain medications and change the way they work.

For example, studies show that warfarin (Coumadin) — used to treat and prevent harmful blood clots from forming — can interact with several vitamins, herbs and beverages. Examples of foods that can interact warfarin (Coumadin) include:

  • Vitamin K-containing foods including avocado, kale, broccoli, soybeans, spinach and more
  • St. John’s wort
  • Ginko biloba
  • Alcohol
  • Cranberry juice

    Talk openly with your health care team about any dietary supplements you currently use or plan to take.

    Unlike prescription medications, dietary supplements and herbal remedies are not regulated by the U.S. Food and Drug Administration. In other words, they don’t go through the same rigorous safety testing. Because of this, different dietary supplements may not contain the same amount of active ingredient. Some products can even contain ingredients not listed on the label.

    However, you can be an educated consumer. Several organizations test supplements to be sure the product was properly manufactured, contains the ingredients listed on the label and not harmful contaminants. For example, supplements that have a USP (US Pharmacopeia) seal on the label contain 95-100% of the active ingredient.

    Some Helpful Hints About Drug Interactions

    • Do not use vitamin or mineral supplements to replace a healthy food-based diet. You can find information on eating well on our Eat Better page. [link to et better]
    • Check with your health care provider before you take any vitamins or supplements, especially if you are on a blood thinner.
    • Read the instructions on the label. Ask your health care providers if you have any questions.
    • Ask about potential interactions with your current medications or other supplements you take. If you are on warfarin or another blood-thinning medication, talk with your doctor about how to keep your intake of vitamin K the same everyday so you can avoid problems.
    • Keep an updated list of all the medications, dietary supplements and herbal remedies you take. Share it with your healthcare providers so they can prevent potentially harmful interactions. Write down the name of each supplement, the dose, why and how often you take it.
    • Find out whether you need to stop taking any supplements or medications before planned surgical procedures. Some supplements can make you more likely to bleed or affect your response to anesthesia.
    • Remember that “natural” does not necessarily mean “safe.” Even though many dietary supplements come from natural sources, it doesn’t mean they can’t have unexpected side effects, especially if you take too much.
    • There is such a thing as too much. Mega doses of vitamins can be harmful. For example, too much iron can result in nausea and vomiting and can damage the liver and other organs.
    • Report side effects. You should tell your doctor about any troublesome reactions. You can also report problems to the FDA by calling 1-800-FDA-1088 or completing this form.

    Questions to Ask Your Doctor

    • Should I be taking any dietary supplements?
    • Are there certain vitamins I should avoid given my current medications?
    • How much is too much?
    • Can I take supplements after the expiration date?
    • Where can I get more information?
    • Is there a particular brand or dose that you would recommend?
    • How, when and for how long should I take it?

    Additional Resources

    Vitamin and Mineral Fact Sheets
    Office of Dietary Supplements

    Recommended Dietary Intakes
    Institute of Medicine

    Time to Talk
    National Center for Complementary and Alternative Therapies

    Avoiding Common Drug Interactions
    U.S. Food and Drug Administration

      Eat Better

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