Zinc is an essential
micronutrient for human metabolism that catalyzes more than 100
enzymes, facilitates protein folding, and helps regulate gene expression. Patients with
malnutrition,
alcoholism,
inflammatory bowel disease, and
malabsorption syndromes are at an increased risk of
zinc deficiency. Symptoms of
zinc deficiency are nonspecific, including growth retardation,
diarrhea,
alopecia,
glossitis, nail dystrophy, decreased immunity, and
hypogonadism in males. In developing countries,
zinc supplementation may be effective for the prevention of upper respiratory
infection and
diarrhea, and as an adjunct treatment for
diarrhea in malnourished children.
Zinc in combination with
antioxidants may be modestly effective in slowing the progression of intermediate and advanced
age-related macular degeneration.
Zinc is an effective treatment for
Wilson disease. Current data do not support
zinc supplementation as effective for upper respiratory
infection, wound healing, or human immunodeficiency virus.
Zinc is well tolerated at recommended dosages. Adverse effects of long-term high-dose
zinc use include suppressed immunity, decreased
high-density lipoprotein cholesterol levels,
anemia,
copper deficiency, and possible genitourinary complications.