Zinc is a metal that the human body needs in only very small amounts. It is because of this that it is in the classification of "essential trace elements." It can help boost the immune system and is used to treat colds and ear infections. Some use zinc for the eye disease "macular degeneration" and for cataracts. It is also used to help cases of asthma, diabetes, high blood pressure, acquired immunodeficiency syndrome (AIDS), and skin conditions such as psoriasis, eczema and acne.
Zinc has been shown to be a common deficiency, and it is critical for optimal immune and antioxidant function. Zinc may also help people think more clearly. One study gave 44 children with ADHD either 55 mg of zinc or placebo each day for six weeks along with their Ritalin (which is overused in ADD). While the behavior of all of the children improved during the study, those who had taken zinc had a more marked improvement. Zinc may play a role in regulating the production of dopamine in the brain, which is associated with feelings of pleasure and reward and deficiency has been linked to ADHD. In addition, a study of seventh graders showed that 20 mg a day of zinc improved school performance with improved memory and attention span. Zinc is found in high protein foods.
Although only small amounts are needed, zinc deficiency can lead to slow wound healing and, in children, stunted growth and acute diarrhea. Low zinc levels can also be associated with male infertility, sickle cell disease, HIV, major depression, and type 2 diabetes.