Yes, we have a drive to kill. Although not carnivores of sharp claws or sharp canines, we have a brain to make tools. Also, there is insufficient B12 in mushrooms, and although yeast contains some B12, it is officially an animal and takes a lot of it, so Vegans have to settle for yeast derived B12 supplement.
If you include dairy products, which includes milk and eggs, then we can get B12.
Iron absorption is superior from meat than vegetables and we need twice the iron from vegetable sources.
We're not herbivores naturally, but probably do best without red meat.
Besides which, even though unhealthy, bacon goes with everything and tastes fabulous.
If you have vitamin B12 deficiency, you could become anemic. A mild deficiency may cause no symptoms. But if untreated, it may lead to symptoms such as:
Weakness, tiredness, or lightheadedness
Heart palpitations and shortness of breath
A smooth tongue
Constipation, diarrhea, loss of appetite, or gas
Nerve problems like numbness or tingling, muscle weakness, and problems walking
Mental problems like depression, memory loss, or behavioral changes