More than half of Americans take dietary supplements, with the multivitamin being the most commonly used, according to a new report from the Centers for Disease Control and Prevention.
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Between 1988 and 1994, 42 percent of the U.S. population said they took at least one dietary supplement. That increased to 53 percent between 2003 and 2006, the report says.
But do these pills really have the power to make you healthier?
Despite their ubiquity, there is no evidence that taking a multivitamin regularly has the ability to ward off chronic diseases, such as cancer and cardiovascular disease, said Roberta Anding, a registered dietician and spokeswoman for the American Dietetic Association.
In general, it's better to get vitamins from food rather than in supplement form. The whole food likely contains other nutrients that are healthy, such as the pigments that give tomatoes their red color, Anding said.
That's not to say you shouldn't take a multivitamin if you want to. But these pills should be viewed as exactly what their name suggests — a supplement to a healthy diet, and not the basis for one.
"If you want an insurance policy, I don’t think there's any harm" in taking a multivitamin, Anding said. "If it's not an insurance policy, but you're trying to use it as the glue that holds together a poor diet — it's not that," she said.
Fruits and veggies are better
A diet high in fruits, vegetables and whole grains has been linked to a decreased risk of cancer, cardiovascular disease, hypertension and stroke, among other diseases. The same can't be said for supplements.
"Whole foods trump supplements in our quest to live better and longer," said Katherine Tallmadge, a registered dietitian and spokeswoman for the American Dietetic Association.
Some nutrients, such as vitamin E found in nuts, are absorbed better by your body when they are consumed in their natural form as opposed to supplement form, Anding said.
On the flip side, nutrients such as folic acid are actually absorbed better in supplement form, she said.
But whole foods have the edge when it comes to other potentially beneficial nutrients, such as pigments and indoles, a compound found in vegetables such as cabbage, broccoli and cauliflower, Anding said.
"There are so many nutrients we haven't even discovered yet," Tallmadge said.
There are cases in which people may need to take dietary supplements because it can be difficult to get enough of certain vitamins and minerals through natural sources alone.
For example, our bodies make vitamin D from exposure to sunlight. But people who live in regions that don't get a lot of sun might need a supplement to ensure they get adequate levels of this vitamin.
In addition, it's recommended that women who are pregnant or are thinking about becoming pregnant take a folic acid supplement to prevent anemia and certain birth defects, according to the National Women's Health Information Center.
There are a few risks to taking supplements. Several vitamins can impact the effectiveness of medications. For instance, vitamin C may interfere with the ability of chemotherapy drugs to work, Anding said. Also, if an individual takes too many minerals at once, the minerals may compete with each other in the body and lead to a deficiency in one of these minerals, Tallmadge said.
If people choose to take supplements, Anding recommends they take ones that provide 100 percent of the daily value for a particular vitamin, rather than high potency vitamins, which often supply a much higher dose of vitamins than you need in a day.
Diet and exercise matter more
Taking supplements may also lead people to believe they are immune to the hazards of eating junk food or getting too little exercise, as was suggested by a recent study.
"They want to be able to eat their french fries and their ice cream and not have to worry about a healthy diet," Tallmadge said. "And just take supplements to make up for it. There's no evidence that they will."
She notes three-quarters of Americans are overweight or obese. "Clearly, those supplements aren’t helping much," Tallmadge said.
A person's lifestyle and overall diet make the most difference in terms of the major chronic illnesses that afflict Americans, she said.