It's always better to try to get what you need from food than from vitamins, or herbs for that matter. Your body absorbs things better in natural form. Eat some red meat.
Uh, I guess I should clarify since I said I use protein powder, but it's mostly because I'm often running out the door and so I add it to my smoothies, but also because I get sick of eggs and steak for breakfast.
I use whey, milk or egg protein, none of that soy crap.