A Vegan's Recovery

Okay, so us Vegas get bashed for not being able to get B12 from animal sources, yet with pretty much all vegan blood tests I’ve heard of (as well as some RAW vegan ones), they all come back with the right amount of B12. And so no, they can’t only come from animal products and nutritional yeast because some vegans that have gotten back positive B12 results have never tried nutritional yeast!! So what’s the deal?
Like really, what else is it in and what’s the truth behind where we get it?