Earlier quoted context omitted.
iirc, that's not quite right. All dietary B12 originates in/on plant sources, you just have to avoid processing that removes it, and include plant sources with good sources. If you try and eat vegan from a typical north american grocery store though, you may have trouble and need to supplement it. On the other hand, selections are pretty good these days, and if you incorporate some nori or legume sprouts (from memory…
Please check your sources. Such advice can be, and in fact is, dangerous to vegans. Legumes or sprouts are not an adequate source of B12 and neither are other plant sources. Your assertion that Nori has B12 is downright wrong. B12 is only synthesized by microorganisms. There are plenty of vegetarian options, but if you are vegan, you have to rely on fortified products and supplements. This has nothing do to with wher…
I appreciate your input, but this level of categorical statement seems to fly in the face of historic and current diets which are vegan or vegan-like and have not relied on supplements, or at least not the type we are talking about here.
At any rate I'd review other dietitians/scientists as well; while it's been a long time since I read the literature on this (when a family member went vegan) your quote certainly wasn't consensus view at that time.
Absolutely agree if you were to eat such a restrictive diet, you have to pay attention to vitamin sources, or you can get sick. B12 particularly problematic because you don't need much at all and can go months/years in a deficit situation before showing any symptoms, which can make it hard to pin down.
(To be clear, when said family member did do this for a while, I suggested supplementing but the nutritional science types I was reading weren't nearly as categorical as your above quote)