I never thought of meat as being an important source of vitamins, but it turns out that there is one very important vitamin that comes primarily from things that
vegans don't eat: Vitamin B-12. The rest of the vitamins and minerals seem to be coming from other things just fine, no need to eat meat for them.
I eat a TON of cheese, so I get plenty of B-12. (Eggs work, too). But my brief internet research has encountered a pretty serious warning to vegans (vegetarians who don't even eat eggs, cheese, milk, etc.) that they need to watch out for this B-12 thing, and the answer is probably to take a vitamin supplement or some fortified cereal or something.
http://en.wikipedia.org/wiki/Vitamin...ources_of_B-12
I have also heard that vegans should be careful to get enough calcium (again, people who eat plenty of cheese should be fine in regards to calcium).
Basically, I'm no doctor or nutritionist, but I think B-12 and calcium are the only big concerns, and that is mainly just for vegans.