Many people take a daily multivitamin to help balance their diets. Some may be following their physician's advice to supplement their diets for medical reasons. But others take them because they've heard vitamins are good for you. Too much of a good thing can potentially hurt you, and vitamins are no exception.

There are numerous brands of multiple vitamins on the market. When buying a multiple vitamin, generally look for one that does not provide more than 100 percent of the daily value (DV) of any of the vitamins it contains.

Taking more than 100 percent DV of some vitamins can cause mild to severe side effects. It is a common myth that all vitamins taken in excessive amounts are excreted out of the body. In fact, some vitamins are stored in tissue and organs and can cause damage. Too much vitamin A, for instance, can cause liver damage and B6 can lead to nerve damage when taken in large amounts.

And you might want to examine why it is you're taking a multiple vitamin in the first place. A multivitamin is necessary when your daily food consumption fails to meet all your vitamin and nutrient needs. Those with healthy, well-balanced diets may not need a multivitamin at all. However, if you know your diet lacks nutritional balance or you're excluding foods from certain food groups, then you may want to consider taking a multivitamin.

How do you know if you are eating a healthy diet? Ask yourself these questions: Do I eat according to the U.S. government's Dietary Guidelines for Americans? Do I consume all servings from the various food groups listed in the USDA MyPyramid food guide? If you answered yes to either question, good for you! You are most likely following a healthy diet. However, if you answered "sometimes or not at all," then a multivitamin is probably something you need to consider. Before taking a multiple vitamin, consult with your physician and/or registered dietitian (RD).