There is a deficiency in a 'normal' vegan diet. 43% of vegans are B12 deficient, and 31% of those who supplement B12 are deficient because they don't know how to dose themselves (sometimes dosages required exceed 100x rda).
Meat doesn't need antibiotics - antibiotics are simply used to increase growth. But there's plenty of antibiotic-free meat - and you can be damned sure I've done my research. This isn't a good argument.
Meat eaters can be unhealthy, or they can be healthy (depending on other habits). In the latter case, no supplementation is required, which is not the case with vegans.
- - - Updated - - -
Misguided. You annihilate billions, if not trillions of microorganisms daily. Is that not harm? Or does harm only apply to some kinds of life?