How does this follow in any way? You know that the distinction of "supplement" and "regular part of the diet" is completely arbitrary, right? What's the difference between regular supplementation and the requirement of "having to hydrate" or "eat your greens for your vitamins" to be healthy? It's even less logical/relevant considering many replacement products add B12 etc on their own by now.

Also factory farmed animals are getting B12 fed as a supplement, which makes this argument even weirder. "Pills bad/not part of the diet", but feeding the same pills to pigs and then eating their meat to get the same nutrients is suddenly "ok and natural/good diet"? Doesn't make sense to me.