[ska]

> however Vitamin B12 can only be found in meat and eggs.

That's not quite right. B12 is mostly produced by bacteria on the surface of plants. We can't synthesize it an neither can the animals we eat. So if you eat products of animals that have been eating such plants (or these days, maybe supplements), there is a source, and especially in developed countries is often the easiest one.

It's an important vitamin, deficiency wise, and for humans there are 3 practical approaches: eat products from animals that consume B12 on plants, eat those plants, or fortify another food more directly.

The 2nd one sounds like an easy win, but is made harder by the fact that most processing (e.g. even vigorous washing ) will remove all the B12 as it is superficial and water soluble.

It's also worth noting we don't need much B12, and we don't need it every day, so managing this isn't very difficult.