You need to check which vitamins each actually contain, and the levels. You can overdose on vitamins. An energy vitamin will be completely uselss if you overdose on vitamin c, which will make you lethargic. Vitamin A overdose in particular can make you very sick.
If you are feeling tired, I would recommend getting your vitamin and mineral levels tested - especially iron and iodine.
Thanks! It is that I need more energy ... I think I ma just going to stock up on pure vitamin b!