Veganism and health is intimately related, but for the worst. The skin, eyes and facial appearance betrays the health condition of a human being. If you take a look at the faces of someone who has been a vegan for more than two or three years, you will see that you can get severely malnourished and your immune system in jeopardy. Yes, veganism is the diet that will put your health in danger of collapsing. It affects your brain and how you perceive yourself, not realizing that you really look like a ghastly wraith.
Not only do we have skeletal muscle mass to maintain but you must also feed a lot of calories and essential vitamins and minerals to your huge brain and complex immune system. All the tissues and organs in your body cannot be maintained on lettuce, carrot, strawberries and poems! To be in good health, Homo sapiens' body needs several essential elements which a vegan's diet lacks: vitamin B12, B6, A retinol, zinc, and, above all, essential amino acids, which our body cannot produce.
Vitamin B12 (extrinsic factor) is only found in meat, beef or chicken liver, egg yolk, cheese, and milk. It is key to the development of a nerve cell dendrite, axon and the myelin sheath that covers it. Vitamin B6 works together with B12; although it is also present in nuts, it is in meat where you can find it in enough quantity to supply you nervous system needs. Retinol is fat-soluble vitamin A, and the only type that can be fully and naturally absorbed into our body; it is found in great quantities in beef/chicken/fish liver, butter, codfish liver oil, and egg yolk as it is essential for your retina, immune system, and skin. Beta carotene vitamin A from carrot and pumpkin is not easily absorbed by our digestive system as you would need about 30 kg of carrot a day to supply half your daily needs for vitamin A. Retinol, on the other hand, is our natural way to consume vitamin A.
Aside from zinc, which is found in great quantities in red meat and mollusk, and vitamin A/B12, our immune system needs lysine, leucine, methionine, tryptophan, and valine, which are some of the essential amino acids that are obtained from animal proteins. For the production of ATP by the cell mitochondria, ketone bodies from animal fat are the best fuel. Contrary to carbohydrates, which produce a lot of harmful free radicals as byproducts, ketone bodies make the mitochondria run more efficiently and produce more ATP. Besides, animal fat does not raise your blood sugar at all, as carbs do; so, it is good for people who suffer from diabetes.