I stopped eating meat in May. I had a blood test in September, and it was normal. I had another one yesterday and my Vitamin B12 level went up since the last one. It's weird - i don't follow a strict diet and i don't take vitamin pills. But a fact's a fact. If anyone who reads this considers becoming vegetarian, but has concerns about health implications - don't you worry. Just say no meat for a week and see what happens. Then another week. Then one more. Than just go on. It's not that that bad. I have less headaches lately if that's any indication.
Oh (edit): It is possible, of course, that i digest B12 exceptionally well. Ask for professional medical advice before making a decision about your diet, but don't be ashamed of eating according to an idea and not only health - just don't put the idea too high.