[wyager]

If your “healthy” diet requires vitamin pills it’s not a healthy diet. Animal diets don’t require you to take pills or do anything weird - the absolute most extreme advice some animal diet people will tell you is that it’s a good idea to eat liver.

[markstos]

The cited B12 vitamin turns out to come from bacteria, not plants or animals. Humans used to get it by eating plants because they weren't washed well. We only get it from non-human animals because they eat things which have the bacteria on them. B12 was already recently found in "water lentils" but I don't think that's commercially available yet.

As far as "doing anything weird", have you looked in how farmers forcibly impregnate cows or what happens baby chicks or dairy calves that have the misfortune to be born male?

[datameta]

I don't personally adhere to a strictly vegan diet. But if one does, and their avoidance of stress hormone metabolites in industrially raised livestock makes them feel better, then taking a vitamin supplement (which is orders of magnitude under the maximum safe dose and therefore without side effects) is the rational choice.