The first signs of zinc deficiency in marginally nourished children are suboptimal growth, anorexia, and impaired taste. The most serious manifestations of zinc deficiency were reported in Iranian dwarfs. These adolescent boys, who consumed large amounts of clay, were retarded in growth and sexual development and had anemia, hypogonadism, hepatosplenomegaly, rough skin, and mental lethargy. After treatment with a well-balanced diet containing adequate amounts of zinc for 1 yr, pubic hair appeared, sexual organs increased in size, linear growth was resumed, and the skin became normal. The anemia responded to iron supplements.
Zinc deficiency develops in some patients with cirrhosis because the ability to retain zinc is lost.
Clinical assessment of mild zinc deficiency is difficult because many of the signs and symptoms are nonspecific. Maternal zinc deficiency may cause anencephaly in the fetus. Secondary deficiency occurs in liver disease, in malabsorption states, and during prolonged parenteral nutrition. Night blindness and mental lethargy may be features. The defect involves the failure to generate a transport protein that enables zinc to be absorbed in the intestine.