The only real thing that meat-eaters do not have to supplement that vegans do is b12 (because livestock are supplemented with it) and maybe omega 3.
So most people should supplement, not just vegans.
Nutrition is a very big component of his plan/blueprint and excluding a very big chunk of the search space (animal based foods) doesn't give me as much confidence that he found an optimal or close to optimal plan (especially compared to the effort required) to achieve his goal.
What do you mean "supplemented"? The vitamin comes from animal sources.
This comment has a lot of sources compiled https://www.reddit.com/r/vegan/comments/7ujsaf/comment/dtlj7...
LOL. Patently false. B12 is produced by bacteria in herbivores' guts.
But actually there's a solution for vegans. As the following paper in Nature eloquently puts it:
"Human faeces contain appreciable quantities of vitamin B12 or vitamin B12-like material presumably produced by bacteria in the colon, but this is unavailable to the non-coprophagic individual."
And when you say annual products, are you talking about all animal products, like seafood? Because there is a vast difference between oysters, muscles, and salmon, and industrial farm raised beef.
And animal products, again, are you excluding the organ meats, which are extremely high in many things that could possibly extend our lifespan? Like riboflavin, manganese, zinc,?
One of his main points in the intro is not destroying our biosphere and going vegan is the single most impactful thing an individual can do to support that. Supplementing B12 is not that hard of a task to ask from a population which already swallows pills and powders by the kilograms a year.