Many current and former cancer patients take vitamin and mineral supplements. They may believe these supplements can help reduce treatment side effects. They may think extra vitamins will keep cancer from coming back or help them live longer. But research in these areas hasn’t yet found whether many of these beliefs are true. And some doctors worry that supplements can interact with cancer treatments or have other unintended consequences.
NIH-funded researchers at the Fred Hutchinson Cancer Research Center wanted to investigate how common supplement use among cancer patients might be. They analyzed 32 studies published between 1999 and 2006 that looked at how many adult cancer patients and survivors used vitamin and mineral supplements.
The researchers found widespread supplement use nationwide. Overall, up to 4 out of 5 cancer patients and survivors took some kind of vitamin or mineral supplement. Breast cancer survivors had the highest rates of use. Up to about 9 in 10 took supplements. In comparison, about half of all U.S. adults take vitamin or mineral supplements.
Up to 70% of cancer patients and survivors who used supplements did not discuss it with their doctors. Yet it’s important for physicians to know when their patients are taking supplements, said Dr. Cornelia M. Ulrich, one of the researchers. “Some vitamins, such as folic acid, may be involved in cancer progression while others, such as St. John’s wort, can interfere with chemotherapy,” she explained.
This study suggests that scientists need to learn more about how dietary supplements affect cancer treatment, survival and quality of life. In the meantime, no matter what your medical condition, it’s always a good idea to discuss any supplement use with your doctor.