Protein is vital for life and growth. It's needed in every cell in our bodies. It's necessary for healthy eyes, muscles, tendons, teeth, skin, hair and nails. It's also needed for things that are constantly working behind the scenes, like antibodies, enzymes, hormones, hemoglobin (blood protein) and neurotransmitters.
When blood is spilled, protein is needed to replace it. Wounds and scars need protein to heal. Cells are dying and being replaced all the time, and this process requires protein.
For hair and nails to grow you need protein. Protein keeps your immune system and nervous system healthy. Protein pinch-hits for any lack of carbohydrates and fat by generating calories your body can use.
Proteins are made up of amino acids. Essential amino acids must come from what we eat. Essential amino acids are isoleucine, leucine, lysine, methionine, phenyalanine, threonine, tryptophan and valine.
Your body can produce non-essential amino acids. Non-essential amino acids are alanine, arginine, aspartic acid, cysteine, cystine, glutamic acid, glutamine, glycine, histidine, proline, serine and tyrosine.
Protein deficiency isn't limited to Third World nations. Poor people may struggle to get enough protein to meet their nutritional needs. People on restrictive diets may be cutting out too much protein.
Body builders and vegetarians must make a point of getting enough protein in their diets. And people can become deficient simply from lack of information on nutrition.
Extreme cases of protein deficiency can lead to kwashiorkor which mainly affects children. Kwashiorkor can cause hair loss and poorly healing wounds.
Liver damage, inadequate immunity, digestive problems, and a general retardation of growth can result. The most extreme situations of protein deficiency end in starvation.
But symptoms of lesser protein deficiency can pose serious problems. Your body goes into starvation mode, extricating muscle out of muscle which then causes muscle wasting, and will rob other protein stores as well.
Weight loss, diarrhea and edema (fluid retention) in the abdomen and legs can occur.