meat or no meat?

Normally, there are people who eat meat but there are another people that don't eat meat for different reasons, not only meat but all comes from animals like milk, eggs... In my opinion, eat meat is a bad idea because the animals have feelings like the humans. But i agree about eat eggs and i drink milk because when i drink milk or eat eggs, i'm not hurting the animal, since eat eggs is like eating somthing that hasn't life or feelings and the milk too. In the following paragraphs I want to explain the advantages of meat and vegetables, fruits …

Firstly, I think that animal flesh has many vitamins and proteins that vegetables (fruits, vegetables ...) do not have. We need to eat meat because this have vitamin B12 (is critical for maintaining brain function and is found only in animal protein), proteins (from meat and dairy are high quality. Those found in plants are lower quality), iron (found in meat is much more easily absorbed by the human body). Meat enabled the human brain to get larger and develop, our bodies are designed to eat bothmeat and plants, if a person is vegetarian and eats meat, I think that in the moment of killing the animal it is not necessary to kill him by causing him to be injured in his death. 

Secondlly, there are vegetarian people because they like animals and do not have the will to kill them.