Effectiveness	Probably effective: zinc deficiency; Wilson disease
	Possibly effective: slow progression of age-related macular degeneration; childhood diarrhea and URI in developing countries
	Probably ineffective: URI, wound healing, human immunodeficiency virus
Adverse effects	Metallic taste, nausea, vomiting, abdominal cramping, diarrhea, suppressed immunity, reduced levels of high-density lipoprotein cholesterol, decreased copper stores, urinary tract infection, nephrolithiasis
Interactions	Penicillamine (Cuprimine), tetracyclines, quinolones; decreased copper absorption
Contraindications	Use with caution in pregnant and lactating women
Dose*	Zinc deficiency: two to five times the recommended dietary allowance† (depending on severity) for six months
	Diarrhea: 5 to 20 mg
	Age-related macular degeneration: 80 mg of elemental zinc with 2 mg of copper, 500 mg of vitamin C, 400 IU of vitamin E, 15 mg of beta-carotene
	Dose should not exceed the tolerable upper intake level‡ for prolonged periods
Cost	$4 to 15 for three-month supply
Bottom line	Safe at doses less than or equal to the tolerable upper intake level‡; useful for zinc deficiency, Wilson disease, and childhood diarrhea in malnourished populations; possibly useful in combination with antioxidant supplements for slowing the progression of age-related macular degeneration