Zinc is an essential trace mineral, or "helper molecule." It plays a vital role in bringing vitamin A from the liver to the retina in order to produce melanin, a protective pigment in the eyes. Zinc is highly concentrated in the eye, mostly in the retina and choroid, the vascular tissue layer under the retina.
Impaired vision, such as poor night vision and cloudy cataracts, has been linked to zinc deficiency. A person with too little zinc in their body is also at risk for alopecia (loss of hair from eyebrows and eyelashes), mental sluggishness and increased susceptibility to infection.
People at high risk for age-related macular degeneration (AMD), or who are already experiencing the early stages of AMD, may benefit from increased zinc intake. The human body does not produce the zinc it needs, so daily intake of zinc through diet, nutritional supplements, or fortified foods and beverages is important for the maintenance of good eye health. Red meat, seafood, poultry, eggs, wheat germ, mixed nuts, black-eyed peas, tofu and beans contain zinc.
The landmark Age-Related Eye Disease Study (AREDS), sponsored by the National Eye Institute, established that AMD is linked to nutrition. The study showed that individuals at high risk for AMD could slow the progression of advanced AMD by about 25 percent and visual acuity loss by 19 percent by taking 40-80 mg/day of zinc, along with certain antioxidants. Taking higher levels of zinc may interfere with copper absorption, which is why the AREDS study also included a copper supplement.
However, high doses of zinc may upset the stomach. Therefore, a follow-up study, AREDS2, which is currently in progress, is testing a more moderate dose of 25 mg/day.
The U.S. Food and Drug Administration (FDA) recommends 11 mg/day of zinc for men and 8 mg/day for women.
For those at high risk for AMD, the AREDS study showed that higher levels of zinc (40-80 mg/day) is beneficial. Zinc supplementation has been known to interfere with copper absorption, so it is strongly recommended that people taking zinc also take 2 mg/day of copper.
The table above highlights good sources of zinc, which include red meat, seafood, poultry, eggs, wheat germ, mixed nuts, black-eyed peas, tofu and beans.
Discover great recipes rich in zinc.
*At this time, the AOA is unaware of any studies that have examined interactions between specific medications and zinc. The AOA also is not aware of any adverse health reports from interactions between specific medications and zinc. However, the AOA recommends consulting with a health care professional before taking any supplements.