Suggestions for Using Supplements


Taking dietary supplements requires that you do some homework, especially if you're getting breast cancer treatment. Before you take anything, make sure you talk to your doctor and a registered dietitian about what you would like to take and discuss all the risks and benefits.

Keep the following points in mind when you're deciding whether or not to use supplements.

Some dietary supplements can interfere with breast cancer treatment and prescription medication.

Supplements can't always be safely taken along with prescription medication. Some supplements can change the way medications and radiation work in your body and may make the treatments less effective. For example, red clover and St. John's wort may interfere with the way tamoxifen works in your body.

Most pharmaceutical companies and supplement producers do not conduct research on how medications and supplements interact, so we just don't know all the risks of taking supplements during treatment. It's very important that you talk to your doctor about any supplements you're thinking about taking.

Dietary supplements are not regulated by the U.S. government.

All prescription and over-the-counter medications sold in the United States are regulated by the U.S. Food and Drug Administration (FDA). But supplements are not classified as medications, so their safety and effectiveness don't have to be carefully tested, as medications must. In other words, all supplements basically are considered "safe" by the government until they are proven unsafe. Medications, on the other hand, must be proven safe and effective BEFORE they can be sold.

This lack of regulation also means that you have no guarantee that the supplement you're buying is pure — meaning that it contains only the ingredients on the label. There's also no guarantee that the supplement has the exact amount of nutrient or herb or botanical in it that the label says it does.

You have to educate yourself before taking a supplement. Ask your doctor and your registered dietitian if there have been any reports of interactions between the supplement you want to take and the breast cancer treatment you are having.

You also have to find reputable manufacturers you can trust to produce consistently high-quality supplements. Prescription and over-the-counter medicines available in the United States must, by federal law, meet the standards of the U.S. Pharmacopeia (USP). The USP also has created a set of standards for dietary supplements. But supplement makers are not required to follow these standards — it's voluntary. A good rule of thumb is to look for a supplement with the USP notation on the label. This means that the company is legally responsible to the FDA for meeting USP standards.

Just because it's natural doesn't mean it's safe.

Many people believe that any food or supplement in its naturally occurring, unprocessed state is better or safer than something that is refined or manufactured. This is not necessarily true. Some of the most toxic substances in the world occur naturally. For example, poisonous mushrooms and poison oak or ivy are extremely toxic to people but are completely natural.

Whether something is natural or synthetic isn't the most important question to ask. The most important questions are:

  • Will it benefit my health?
  • Is it safe?
  • Will it interact with any other medications or treatments I am receiving?
  • Does it have consistent and accurate doses?
  • Is it free of contaminants?

You should be able to get almost all of the nutrients you need from the food you eat, especially fruits and vegetables. Your doctor or registered dietitian also may recommend that you take a multivitamin/mineral supplement or specific nutrients if your diet lacks them or if you need an extra amount of a certain nutrient.

Expert Quote

"Using supplements during treatment with chemotherapy, Herceptin (chemical name: trastuzumab), and radiation is an area of significant controversy. It's very difficult to conduct clinical research in this area. Based on the mechanisms of action, most oncologists, oncology dietitians, and oncology nurses recommend avoiding antioxidant supplements above the daily required amounts during treatments."

-- Cyndi Thomson, Ph.D., R.D.

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