Table 2.
Key Points About Zinc Supplements
| 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 |
URI = upper respiratory infection.
*
All doses are for milligrams of elemental zinc per day.
†
Recommended dietary allowance 2 (by age) = 0 to 6 months: 2 mg; 7 months to 3 years: 3 mg; 4 to 8 years: 5 mg; 9 to 13 years: 8 mg; 14 to 18 years: 11 mg (boys), 8 mg (girls); older than 19 years: 11 mg (men), 8 mg (women); pregnancy: 11 mg; lactation: 12 mg.
‡
Tolerable upper intake level per day 2 (by age) = 0 to 6 months: 4 mg; 7 to 12 months: 5 mg; 1 to 3 years: 7 mg; 4 to 8 years: 12 mg; 9 to 13 years: 23 mg; 14 to 18 years: 34 mg; older than 18 years: 40 mg.