1) Special proteins produced by the body in response to foreign substances including bacteria and viruses; there are five structurally distinct classes of immunoglobulins produced by plasma cells in the bone marrow and other lymphoid tissue that bind to and neutralize foreign substances (antigens).
People give up eating meat and animal products such as milk, cheese, and eggs for many reasons. But doing so may increase the risk of anemia, a potentially serious condition in which the body does not make enough oxygen-bearing red blood cells. For vegetarians who eliminate meat, anemia can be due to an iron deficiency.
Iron helps red blood cells carry oxygen to all parts of the body. Symptoms of iron-deficiency anemia include weakness and fatigue, lightheadedness, and shortness of breath. Iron-rich foods include red meat, pork, fish and shellfish, poultry, lentils, beans and soy foods, green leafy vegetables, and raisins. Some flours, cereals, and grain products are also fortified with iron. Teen guys need 11 mg of iron a day and teen girls need 15 mg.