For what it's worth, a very reputable independent study of many multi vitamins on the market found that many of them were not true to their labels, and included much less nutrients than advertised. Ironically, some of the worst offenders were among the most expensive "boutique" vitamins. I recall that One-a-Day scored very well, and that, while being among the cheapest and most available in stores, was very truthful about its contents.
I do take 1/2 serving of a multi vitamin daily (i take one rather than the two they recommend) from Trader Joe's. As was said above, placebo effect or not, I have felt more energetic since I started it. Also, I take a vitamin D supplement because my bloodwork revealed that I've been consistently very low on that. I haven't addressed this deficiency through food, so I'll be interested to see if my next round of bloodwork shows that the D supp has helped.
Starting: 11/14/2010, 350 lbs (Yikes!)
Current : 03/31/2010, 295 lbs
Starting:1/20/2012, 335 lbs
Current: 2/10/2012 324.4 lbs
Goal 1: 302 lbs 04/01/2012 April Fools 10% Challenge
Goal 2: 271 lbs 07/04/2012 4th of July 10% Challenge
Goal 3: 247 lbs 10/01/2012
Ultimate Goal 160 lbs 05/31/2013
Lost: 10.6 lbs