Developmental zinc deficiency and behavior.

The majority of studies of developmental zinc deficiency and behavior were conducted in laboratory animals, primarily rats and rhesus monkeys. Effects on food intake complicate interpretation of experiments using severe zinc deficiency. Severe zinc deficiency in rats during the period of rapid brain growth has similar effects to protein calorie malnourishment during this period, including altered emotionality and food motivation. When behavior is tested during a period of zinc deprivation in immature animals, lethargy (reduced activity and responsiveness) is a prominent characteristic, but learning, attention and memory are also affected. The few supplement studies available in children did not report effects on behavior. Although zinc has multiple roles in brain function, considerable brain sparing occurs in zinc deficiency, and peripheral mechanisms of altered behavior also need to be considered.