Zinc

A trace element that is essential for normal growth, the development of the reproductive organs, normal functioning of the prostate gland, healing of wounds, and the manufacture of proteins and nucleic acids in the body. Zinc also controls the activities of more than 100 enzymes and is involved in the functioning of the hormone insulin. Particularly rich sources of zinc include lean meat, wholemeal breads, whole grain cereals, dried beans, and seafood. Zinc deficiency is rare. Most cases occur in people who are generally malnourished. Deficiency may also be caused by any disorder that causes malabsorption; acrodermatitis enteropathica; or by increased zinc requirements due to cell damage (for example, as a result of a burn or in sickle cell anaemia). Symptoms of deficiency include impairment of taste and loss of appetite; there may also be hair loss and inflammation of the skin, mouth, tongue, and eyelids. In children, zinc deficiency impairs growth and delays sexual development. Prolonged excessive intake of zinc may interfere with the intestinal absorption of iron and copper, leading to a deficiency of these minerals. Zinc compounds, such as zinc oxide, are included in many preparations for treating skin and scalp disorders.