I've read a few places that taking B vitamins can significantly boost your metabolism. I'm not sure if this is true or not, but it definetely couldn't hurt to give it a try!
You are so right. Everyone should make sure they eat enough foods, chock full of healthy minerals and vitamins. Eating right is ALWAYS the best way. B-12 is not absorbed from a swallowed pill; it is absorbed sub-lingually or sub-Q~
The B complex I take helps me tremendously. Always has, when I feel the beginning of an afternoon crash coming on, I take one and I feel awake and energized again.