It seems like medical researchers go back and forth on whether taking a daily vitamin helps you or not. The most recent study, as reported on, is that a daily multivitamin is no more effective than a placebo. In other words, multi-vitamins are useless.

The study covered 12 years and almost 6,000 participants and found that multivitamins did not help the participants in any discernible way. I've been taking a multivitamin every day for years, if not decades and while I've been told that all I'm doing is producing expensive urine, I think now I will swear off them. Until the next study, anyway.