[throwaway5752]

In case you are serious, vitamin B12 is produced by single celled organisms. It is found in algal (seaweed) and fermented foods, too, not just animal based foods.

Almost every study about responsible plant based diets shows it has healthier than average outcomes. I say "almost" just as a hedge, I don't know of any.

By all means, eat whatever diet you want and don't feel bad about it, but do it for factual reasons and don't invent facts to justify your preferences.