Zinc Deficiency

Zinc (Zn) is contained mainly in bones, teeth, hair, skin, liver, muscle, leukocytes, and testes. Zinc is a component of several hundred enzymes, including many nicotinamide adenine dinucleotide (NADH) dehydrogenases, RNA and DNA polymerases, and DNA transcription factors as well as alkaline phosphatase, superoxide dismutase, and carbonic anhydrase.

A diet high in fiber and phytate (eg, in whole-grain bread) reduces zinc absorption.

(See also Overview of Mineral Deficiency and Toxicity Overview of Minerals Six macrominerals are required by people in gram amounts. Four cations: Sodium, potassium, calcium, and magnesium Two accompanying anions: Chloride and phosphorus Daily requirements range from... read more .)

Dietary deficiency is unlikely in healthy persons. Secondary zinc deficiency can develop in the following:

Maternal zinc deficiency may cause fetal malformations and low birth weight.

Zinc deficiency in children causes impaired growth, impaired taste (hypogeusia), delayed sexual maturation, and hypogonadism. In children or adults, manifestations also include alopecia, impaired immunity, anorexia, dermatitis, night blindness, anemia, lethargy, and impaired wound healing.

Zinc deficiency should be suspected in undernourished patients with typical symptoms or signs. However, because many of the symptoms and signs are nonspecific, clinical diagnosis of mild zinc deficiency is difficult. Biotin, riboflavin, and essential fatty acid deficiencies may resemble zinc deficiency. Laboratory diagnosis is also difficult, requiring special collection techniques. Low albumin levels, common in zinc deficiency, make serum zinc levels difficult to interpret; urine zinc levels are unreliable for acute deficiency, as are hair zinc levels. If available, isotope studies can measure zinc status more accurately.

Treatment of zinc deficiency consists of elemental zinc 1 to 3 mg/kg orally once a day until symptoms and signs resolve.