Answer: Any supplement can interfere with any prescribed medication. This is true of herbal products as well as nutritional supplements. Just because something is natural does not mean it's safe. Some vitamins, for example, can affect your body's ability to clot blood, and may block or enhance the effect of one of your prescription medicines. You should take this opportunity to discuss your supplement regimen with your primary health care provider.
Jamie in Florida asks: Are vitamin waters safe to drink, and do we need to worry about mixing certain types?
Answer: As Dr. David Katz reported for ABC News previously (abcnews.go.com/GMA/OnCall/story?id=969246), most of us do not need the additives put in high-priced, specialized vitamin waters. Many of these drinks contain large amounts of sugar and salt with minuscule doses of vitamins, and you are probably better served by drinking plain water. Since these vitamin sources are not regulated as medicines, but as food, there is no way to know what, if any, health benefit or harm may result from drinking them.
Alex in Brentwood, Calif., asks: I just started taking Juice Plus brand vitamins. They are all natural, 17 fruits and vegetables. Are these natural vitamins better than the manufactured kind? Thanks!
Answer: Juice Plus is one of several brands of fruits-and-vegetables-in-a-pill or in a powder. The theory is grand -- we all need several servings of fruits and veggies a day, and it's quicker and easier to pop the pill than eat the food. Even if these supplements contained fresh, organic produce, it would still be better for you to eat the actual, whole foods. It is unlikely that your body absorbs the healthy nutrients from vitamins the same way it does from actual foods. If used, vitamins should be viewed as insurance policies against deficiencies and as tools to promote optimal health, not as a replacements for good, healthy eating.