I know people have been hating on this article because it only addresses a few specific conditions, but it is one in a long line of studies that have shown vitamin supplements to have no positive (and occasionally negative!) effects, unless you are actually deficient in that vitamin.
People are so taken by advertisements and anecdotes about vitamins that they neglect the reality. If you hear a commercial that says "You might be deficient in X!" you suddenly need to take that vitamin/mineral "just in case." Rinse and repeat for every single vitamin, mineral, or "energy/immune/etc booster," and suddenly you're taking 100+ supplements and spending an excessive amount on useless pills.
The takeaway is this:
Unless you actually have a condition that requires you to supplement a specific nutrient, you do not need to take vitamins, to say nothing of multivitamins.
If you are concerned that you are actually deficient, go get a blood test from your doctor. Saving yourself the cost of supplementation over the next 20 years when you find out that you don't actually need them will more than pay for the appointment.