I was thinking of supplementing with Usana Essentials multi (http://www.usana-nutritionals.com/products/USNUPRODUCT_39383.html), but I'm concerned about getting too much of some vitamins. Right now I eat enough to get a wide variety of vits and minerals, plus I get two scoops of Isopure protein powder (http://www.naturesbest.com/index.html?section=Shopping&id=3004&catSec=207&pid=17499) per day, but I don't know how effective the vitamins in the protein powder are. Would that be too much?

Depends if there non toxic, Wait till Jeremy get's here and he'll sort everything out.

Vitamin C and B vitamins are water soluble and flush out anything you don't use you piss right out. If you've just starting taking a multi, and you've noticed that your piss is now neon green, that's probably the aforementioned b vitamins. A and E are the ones that you don't wanna over do as they can build up faster then your body can use them.

Stay under 100,000 IU's for A, and 1000 mg's for E, and you should be alright. For vitamin A, it also depends on the source. I think beta carotene is the better one but don't quote me on that

http://www.emedicine.com/emerg/topic638.htm