The most bioavailable foods are animal foods. Plant form iron is not even remotely comparable to heme iron.
Heme iron is found only in meat, poultry, seafood, and fish.
Take a iron deficient person and give them plant iron and it will be weeks to never before their iron returns. Feed them a liver and see it spike up in a day.
The same can be said of vitamin A and many other vitamins.
A
No indigenous society on earth has ever been vegan. Even horses who eat grass sometimes eat birds.
Hong Kong has one of the highest life expectancies on earth and one of the highest meat consumption rates on earth.
Every "Vegan" body builder got their start on whey protein. And are in their 20's usually. There is no good 50+ year old long term vegan body builders who aren't on massive amount of steroids and who didn't get their start on animal protein.
Vegan farming is unsustainable. Animals naturally help the soil become more nutritious.
Vegan foods are terrible for the environment. Mass produced mono crops destroy the soil.
Being a vegan is OK if you want to destroy your body. Pushing it on children is evil because it will limit their growth.