I want to start taking multivitamins just so I'm getting my daily nutrients, but I'm a little worried how I might react to some of the stuff in them. I have GNC's Mega Men which are a year after the "best by" expiration date (does that matter?). Here's a list of nutrients I'm not sure about:Vitamin KThiaminRiboflavinNiacinBiotinPantothenic AcidIodineCalciumMagnesiumZincSeleniumCopperManganeseChromiumMolybdenumAmino Acid Blend: Taurine, L-Methionine, L-Glutamine, L-Arginine, L-CarnitineHopefully, there's a pharmascist on the board. I'm assuming the amounts are too small to make a difference but I just wanna make sure.