Arginine is an amino acid (L-arginine) that is made by the body and obtained from diet; necessary for the body to make proteins. It is found in many foods that have protein – therefore, deficiencies are rare. Arginine-rich foods include red meat, fish, poultry, wheat germ, grains, nuts and seeds, and dairy products. As a natural dietary supplement, arginine has received a lot of attention lately for its potential heart benefits.