You may wonder if you should take vitamin or mineral supplements after breast cancer treatment.

Certain supplements may help with symptoms from treatment or boost your overall health. But so far, there’s no proof that any vitamin, mineral, or herbal supplement lowers your risk of breast cancer coming back.

First, Talk to Your Doctor

Before you take any vitamin, mineral, or herbal supplement, talk to your doctor. Research is limited on supplements and studies show mixed results on the safety of supplements and breast cancer.

“Any supplements after breast cancer treatment should be regulated by your oncologists,” says Anita Johnson, MD, breast cancer program director at Cancer Treatment Centers of America in Atlanta. Your medical team knows your symptoms and your full medical history and can tell you what may be best for you.

Vitamins and Minerals in Your Diet

Most doctors and dieticians recommend following a healthy diet after breast cancer treatment.

Research suggests that a diet high in fruit and vegetables, lean proteins like chicken and fish, and whole grains, and a diet low in refined sugars, fats, red meats, and processed meats may help you live longer. A diet that’s high in fiber is also linked to lower risk of breast cancer.

In general, it’s best to get nutrients from foods rather than supplements, says Kelly Rashid, a registered dietician in Fort Lauderdale, FL, who specializes in oncology nutrition. A nutrient-rich diet can help you get important vitamins and minerals to feel good and boost your health.

Vitamins and Minerals in Supplements

Your doctor may recommend certain vitamins and supplements to help you stay healthy after treatment.


Chemotherapy can weaken your bones. A calcium supplement with vitamin D, which helps your body absorb calcium, may protect your bones from changes due to treatment.

Multivitamin. A regular multivitamin may help you get essential vitamins and minerals to improve your overall health.

Probiotics. “Probiotics help boost immunity,” says Tara Scott, MD, a women’s health specialist in Akron, OH. This may help you stay healthy after your treatment. Probiotics have anti-inflammatory effects, which may help protect against cancer. But there isn’t enough research yet to know for sure.

Vitamin D.
Experts say there’s a link between low levels of vitamin D and breast cancer. There’s no evidence a vitamin D supplement will lower your risk of recurrence, but your doctor may recommend it for your overall health.


Supplements to Avoid

Some supplements can do more harm than good. They may affect the way your prescription medicine, chemotherapy, and radiation work.

Avoid those that interfere with any prescription drug, Rashid says. “There are supplements known to interfere with anti-hormonal agents used for breast cancer.”

If you take tamoxifen, it’s best to avoid red clover, St. John’s wort, and black cohosh. Also skip DHEA, licorice, and red clover, because they may affect your hormone levels.

Avoid soy supplements, which are often marketed to reduce symptoms of menopause, Rashid says. Eating whole sources of soy is OK, but don’t go overboard.

If you’re still in treatment, your doctor may tell you to avoid antioxidants. A recent study found that breast cancer patients who took antioxidants during chemotherapy had a higher risk of breast cancer coming back. Antioxidants include vitamin A, vitamin C, vitamin E, carotenoids, and Coenzyme Q10.

Can Supplements Prevent Breast Cancer From Coming Back?

So far, there’s no proof that any vitamin, mineral, or herbal supplement can treat breast cancer or prevent it from coming back.

“To date, there are no studies which demonstrate that certain supplements will lower your risk of recurrence,” Johnson says. They may help with symptoms, but there isn’t enough research to support using them to prevent breast cancer.

But there are other things you can do to lower your risk of breast cancer coming back. Make these lifestyle changes:

  • Eat a healthy diet.

  • Exercise regularly.
  • Maintain a healthy weight.
  • Limit alcohol.
  • Don’t smoke.
  • Lower your stress.
  • Keep up with your regular health screenings.
  • Talk to your doctor if you notice any changes.

Keep This in Mind

Remember, dietary supplements aren’t regulated in the United States. Just because they’re on the shelf doesn’t mean they’re good for you. Unlike medication, supplements don’t have to be proven safe or effective. What they claim on the label isn’t necessarily true.

Before you take any vitamin, mineral, or herbal supplement, talk to your health care team. They can help you decide which may be safe for you after breast cancer treatment, and which ones to avoid.

There isn’t enough research on how medications and supplements interact, so the risks are unclear.



American Cancer Society: “Can I Lower My Risk of Breast Cancer Progressing or Coming Back?” “Study Finds Antioxidants Risky During Breast Cancer Chemotherapy.”

Anita Johnson, MD, breast cancer program director, Cancer Treatment Centers of America, Atlanta.

Kelly Rashid, RD, Fort Lauderdale, FL. “Dietary Supplements,” “Suggestions for Using Supplements,” “Vitamin D.”

Tara Scott, MD, Revitalize Medical Group, Akron, OH.

MD Anderson: “Probiotics: Healthy Bacteria for Your Gut.”

Living Beyond Breast Cancer: “September 2015 Ask the Expert: Vitamins and Supplements.”

Johns Hopkins Medicine: “Reducing Risk of Recurrence.”

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