Is your multivitamin worth it? Probably not

For millions of Americans the idea of taking one multivitamin a day has been drilled into their heads. Marketing can be persuasive. But is the daily popping of these vitamins really necessary?

For most people, the answer is probably not. But, still, U.S. consumers shell out more than $4 billion a year on multivitamins, accounting for well over half of all vitamin sales, according to industry data.

"It's absolutely wrong to take a multivitamin every day. It's a waste of money," said Dr. Stephen Barrett, who runs the Web site Quackwatch. "It's not difficult to scare people because there is no simple way for people to measure what they need or if they are missing something."