B12 usually comes from bacteria in soil (and not meat directly) that we don't get now because of cleaner vegetables and cleaner water. Likewise, many industrial

B12 usually comes from bacteria in soil (and not meat directly) that we don't get now because of cleaner vegetables and cleaner water. Likewise, many industrial animals kept indoors won't get as much B12, so that's why they're given B12 supplements. If you avoid meat, you can just take B12 supplements directly instead of them being filtered through an animal first. If you think this sounds "unnatural", there's nothing natural about intensive animal farming which is where most people get their meat from.