(CNN) -- As more than half of U.S. adults are popping vitamins and supplements, the question remains -- has it made Americans healthier? That depends on whom you ask. The Centers for Disease Control and Prevention said Wednesday that more of half of U.S. adults use dietary supplements -- including multivitamins, minerals and herbs. That rise, from 42% in 1988 to 53% in 2006, has fueled the growth of the supplement industry to a $27 billion behemoth, according to Consumer Reports.

Dietary supplements are not regulated by the U.S. Food and Drug Administration in the same way as drugs. The makers do not have to prove safety or effectiveness. "There's a false perception that supplements fall under the same regulatory umbrella as prescription drugs," said Dr. Orly Avitzur, medical adviser for Consumer Reports. "That's not the case." "We really don't know what's inside." FDA cracks down on tainted dietary supplements The most popular supplements are multivitamins, used by 39% of U.S. adults in 2006. Some consumers mistakenly view supplements as a way to make up for a poor diet. "It's a Band-Aid approach to think you can eat poorly and just take a vitamin and you'll be equal to another person who eats well and exercises and takes care of their health and gets regular checkups," Avitzur said. "There's no substitute for a healthy lifestyle." While some are helpful, supplements can't entirely replace proper nutrition, said Roberta Anding, an American Dietetic Association spokesperson. "I will always say the reason to eat fruits and vegetables -- it's not vitamin C, it's because of the colors, it's the words you can't pronounce," she said, referring to nutrients like lycopene, quercetin or indoles. "That's the reason you eat fruits and vegetables. To just throw