Don't you need to take B12 supplements? Isn't that proof veganism is unnatural?

The objection

“A vegan diet can’t supply B12 without a manufactured pill. Surely that’s nature telling you the diet is wrong.”

The answer

It sounds airtight, and it rests on a factual error about where B12 comes from.

B12 is made by bacteria, not by animals. No plant and no animal synthesises cobalamin; only microorganisms do, using cobalt. Cattle and sheep get theirs because gut bacteria produce it, provided the animal eats enough cobalt. When pasture soils run low, those animals go deficient, so farmers supplement livestock with cobalt or B12 directly, via feed, boluses and injections. A large share of the B12 made industrially is fed to animals, not people.

So the meat on the plate is often a B12 supplement that passed through a cow first. The vegan takes the same vitamin and skips the intermediary, and the markup. Asking “why must vegans supplement?” while ignoring that the animal was supplemented too is selective attention dressed up as an argument.

Why can’t we get B12 from our own gut bacteria, as cattle do? Ours live in the large intestine, past where we absorb it, and modern sanitation strips out the soil and faecal traces our ancestors picked it up from. What changed was our hygiene, not the diet.

The practical point is decisive: supplementation is trivial. A cheap weekly tablet or fortified foods cover it entirely. And deficiency is not a vegan problem at all. It’s common in older adults regardless of diet, because absorption falls with age and certain medications. Plenty of meat-eaters are deficient and never know. The Academy of Nutrition and Dietetics regards a B12-supplemented vegan diet as fully adequate.