^My personal (totally not a doctor at all) advice would be to ditch the vitamins altogether. The consensus is changing not only on the value, but the risk of taking vitamins (and they are risky, they are the most common thing for children to OD on in this country). Except in the case where an individual is severely deficient in a particular vitamin, the newest medical guidelines no longer recommend taking supplements. The evidence has shown that the benefit is vague and uncertain, and it is looking more and more like they don't actually do any good. On top of that, the evidence is mounting that they do harm, not only in cases of overdose, but in normal doses too, by putting strain on the liver, and even possibly increasing the risks of certain types of cancer: recently a few longitudinal and well-designed studies have shown that men who take multivitamins are at higher risk for colon cancer. Of course, other studies show a decreased risk for other cancers -- so it's up in the air.
Ultimately, I think people tend to think it is harder to get all the vitamins and minerals they need in their diet than it actually is. It's really not hard at all, as long as you eat a variety of foods that include fruits and vegetables every day, you'll get everything you need just fine.