NATIONAL (NBC) - Americans spend more than $20 billion a year on vitamin supplements, but recent studies suggest they might not have the affect most had hoped.
In fact, some believe they may not work at all.
Experts say there's an easy way to make sure you're getting the vitamins you need without depending on a pill.
Dietitians say you'll get more bang for your buck by shifting your focus from taking a pill to eating healthy foods.
For example, one cup of cantaloupe gives you more than 100 percent of your Vitamin C needs.
"Oranges have lots of Vitamin C, beans have lots of protein, broccoli has lots of Vitamin C, dark green leafy vegetables have lots of folate and calcium," explains clinical dietitian Ginnie Collins.
Experts say stock your cart with the colors of the rainbow: Red, orange, yellow, green, blue, and purple.
"Nature provides us with all these colorful vegetables and fruits, and if we eat them every day than we're going meet the majority of the needs that we have," Collins adds.
Still, some people need a supplement.
Pregnant women need extra folic acid, and some elderly need more B12.
But these are exceptions to the rule, for the majority the sure way to stay healthy is to keep a colorful cart.
Representatives from the vitamin industry say the best advice for consumers is to engage in a lifetime of healthy habits, including not smoking, maintaining a healthy weight, eating a well-balanced diet and appropriately supplementing with vitamins.
They encourage scientists to conduct new studies that are designed to answer questions about the effects of nutrients on chronic disease.