Much of what is known about severe zinc deficiency was derived from the study of individuals born with a genetic disorder (‘acrodermatitis enteropathica’) resulting from the impaired uptake and transport of zinc. Oral zinc therapy results in the complete remission of symptoms, though it must be maintained indefinitely in individuals with this genetic disorder (4, 64).
Although dietary zinc deficiency is unlikely to cause severe zinc deficiency in individuals without a genetic disorder, poor absorption of zinc from food (‘malabsorption’) or conditions of increased zinc loss, such as severe burns or prolonged diarrhea, may also result in severe zinc deficiency.
It has become apparent that milder zinc deficiency contributes to a number of health problems, especially common in children who live in developing countries. The lack of a sensitive indicator of mild zinc deficiency hinders the scientific study of its health implications.
Individuals at risk of zinc deficiency include infants and children, pregnant and breast-feeding (‘lactating’) women (especially teenagers), patients receiving total intravenous nutrition (‘parenteral nutrition’), malnourished individuals (e.g., those with anorexia nervosa), individuals with severe or persistent diarrhea, malabsorption syndromes, inflammatory bowel disease (e.g., Crohn's disease and ulcerative colitis), alcoholic liver disease, and sickle cell anemia, as well as older adults (65 years and older), and strict vegetarians (4).
The symptoms of severe zinc deficiency include the slowing or cessation of growth and development, delayed sexual maturation, characteristic skin rashes, chronic and severe diarrhea, immune system deficiencies, impaired wound healing, diminished appetite, impaired taste sensation, night blindness, swelling and clouding of the corneas, and behavioral disturbances.
The symptoms of mild zinc deficiency include impaired physical and neuropsychological development and increased susceptibility to life-threatening infections in young children (64).
Authored by Dr Peter Engel in 2010, reviewed by Giorgio La Fata on 29.09.2017