The soil in many areas of America are also low in selenium. Zinc is important for enzyme systems in the body. It promotes a healthy immune system and speeds wound healing. It is needed for normal taste and smell, prostate gland function, growth, and sexual maturation. Mild, subclinical zinc deficiency is probably a common phenomenon.
Zinc deficiency is especially common in children and women.
The ability to absorb zinc declines with age. Marginal zinc deficiency in children can cause poor appetite, poor growth, and impaired taste. Breastfeeding mothers who are zinc deficient may pass on zinc deficiency to their infants. Zinc found in breast milk is better absorbed than zinc found in formula, even though there are similar levels. Zinc levels are lowered by diarrhea and fiber consumption and a significant amount of zinc is lost in perspiration.