Zinc deficiency

[Agnes]

Zinc deficiency has many causes, including various disorders, alcoholism, and use of diuretics.

People lose their appetite and hair and may feel sluggish and lose their sense of taste.
Doctors measure the zinc level in blood and urine, but these tests may not accurately determine zinc status.
Zinc supplements taken by mouth can cure the deficiency.

Zinc is widely distributed in the body—in bones, teeth, hair, skin, liver, muscle, white blood cells, and testes. It is a component of more than 100 enzymes, including those involved in the formation of RNA (ribonucleic acid) and DNA (deoxyribonucleic acid). (See also Overview of Minerals.)
The level of zinc in the body depends on the amount of zinc consumed in the diet. Zinc is necessary for healthy skin, healing of wounds, and growth.
Much of the zinc consumed in the diet is not absorbed. A diet high in fiber and phytate (present in whole-grain bread, bran, beans, soybeans, other legumes, and nuts) reduces zinc absorption.
Many conditions can increase the risk of developing zinc deficiency. Deficiency due to a diet low in zinc is uncommon in developed countries. Zinc deficiency is more common among older people who live in institutions and people who are homebound.
In acrodermatitis enteropathica, a rare hereditary disorder, zinc cannot be absorbed.

[Zipporah Schumaker]

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

Patients taking diuretics
Patients with diabetes mellitus, sickle cell disease, chronic kidney disease, liver disease, chronic alcoholism, or malabsorption
Patients with stressful conditions (eg, sepsis, burns, head injury)
Elderly institutionalized and homebound patients (common)

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. Laboratory diagnosis is also difficult. Low albumin levels, common in zinc deficiency, make serum zinc levels difficult to interpret; diagnosis usually requires the combination of low levels of zinc in serum and increased urinary zinc excretion. If available, isotope studies can measure zinc status more accurately.
Treatment of zinc deficiency consists of elemental zinc 15 to 120 mg orally once/day until symptoms and signs resolve.