Zinc is one of the main ingredients in the AREDS and AREDS2 eye formulas. In the original AREDS trial, zinc plus copper lowered the risk of moving from intermediate to advanced age-related macular degeneration (AMD) by 21%, and the full formula by about 25%, according to the National Eye Institute. The tested dose, 80 mg a day, is twice the upper limit for adults, and 2 mg of copper is added to reduce the risk of copper deficiency from high zinc intake. These results apply to people who already have intermediate AMD or late AMD in one eye, not to preventing AMD.
On an eye vitamin label, zinc stands out: the amount is far higher than in a typical multivitamin, and it comes with a small amount of copper. This article explains why both minerals are there and what the trials found. For the other ingredients, see our guides to vitamin C and vitamin E and lutein and zeaxanthin.
Why researchers looked at zinc
Interest in zinc started with observational studies, which compare what people eat with the health problems they later develop. The NIH Office of Dietary Supplements (ODS) zinc fact sheet describes two of them. One followed 4,170 adults aged 55 and older in the Netherlands. Another looked at 2,464 adults aged 49 and older in Australia, where people with the highest zinc intake (at least 15.8 mg a day) had a 44% lower risk of any AMD.
Studies like these can show a link, but they cannot prove cause and effect. Randomized trials, like those run by the National Eye Institute (NEI), are designed to answer that question.
What the AREDS trial found for zinc
The Age-Related Eye Disease Study (AREDS) enrolled 4,757 people aged 55 to 80 at 11 clinics. In the part of the study focused on AMD, 3,640 people were followed for an average of 6.3 years. They took one of four daily options: antioxidants (vitamins C and E and a carotenoid), 80 mg of zinc (as zinc oxide) with 2 mg of copper (as cupric oxide), antioxidants plus zinc, or a placebo.
NEI summarizes the results as the drop in risk of progressing from intermediate to advanced AMD, compared with placebo:
| AREDS group | Lower risk of advanced AMD | Lower risk of vision loss |
|---|---|---|
| Full formula (antioxidants plus zinc and copper) | 25% | 19% |
| Zinc plus copper | 21% | 11% |
| Antioxidants alone | 17% | 10% |
Source: NEI, About AREDS and AREDS2. None of the groups reduced cataract surgery.
The published trial report, AREDS Report No. 8, reports the results as odds ratios. An odds ratio below 1.0 means lower odds than placebo. For antioxidants plus zinc, it was 0.72, which was statistically significant. For zinc alone it was 0.75, and for antioxidants alone 0.80; neither was statistically significant in the full group. The combination also lowered the odds of moderate vision loss (odds ratio 0.73). The report found no statistically significant serious side effect from any of the formulas.
A later Cochrane review (2023) pooled trials of zinc against placebo and found an odds ratio of 0.83 for progression to late AMD. Most of that evidence came from AREDS. If odds ratios are new to you, our guide to the AREDS and AREDS2 trials explains them in plain English.
Who benefited, and who did not
The benefit showed up in people at higher risk. In AREDS Report No. 8, people with only small drusen or milder changes had just a 1.3% chance of reaching advanced AMD in 5 years. When they were set aside, the odds ratio for the full formula in the higher-risk group was 0.66.
The NEI AREDS/AREDS2 FAQ puts it simply: the formulas benefited people with intermediate or late AMD, with no benefit for people with early AMD or without AMD. NEI also says that nutritional supplements cannot prevent AMD. Our article What Is AREDS2 and Who Needs It? goes into this in more detail.
How much zinc is 80 mg?
According to the ODS zinc fact sheet, adult men need 11 mg of zinc a day and adult women need 8 mg. The upper limit for adults is 40 mg a day. That limit is based on levels that harm copper status.
The 80 mg versus 25 mg question
The second trial, AREDS2, also tested whether less zinc would work. Some participants were randomly assigned to a version with 25 mg of zinc instead of 80 mg. The AREDS2 results in JAMA (2013) showed no difference in progression to advanced AMD between the two doses.
Ten years of follow-up in 3,882 people told the same story. In AREDS2 Report 28, the hazard ratio for low versus high zinc was 1.04. A hazard ratio this close to 1.0 means the two groups progressed at about the same rate.
Even so, NEI still points to the 80 mg dose. The ODS zinc fact sheet says researchers viewed the 25 mg finding as preliminary, and that NEI recommends an AREDS formula with 80 mg of zinc. NEI explains why: AREDS2 had no placebo group for zinc, so the placebo-controlled AREDS results with 80 mg are still considered the gold standard.
You will find formulas on store shelves that use 25 mg of zinc, and others that use 80 mg. If you are unsure which fits you, that is a good question for your eye doctor. Our label comparison of AREDS2 supplements shows how the doses differ.
Why copper is in the formula
According to NEI, copper has a protective job in the formula. The NEI FAQ says copper was added to formulas containing zinc to reduce the risk of copper deficiency anemia, which can come from taking high amounts of zinc. NEI also notes there is no evidence that 2 mg of copper was harmful.
ODS explains the link. The ODS zinc fact sheet says taking 50 mg of zinc or more for weeks can interfere with copper absorption, lower immune function and reduce HDL ("good") cholesterol. The ODS copper fact sheet adds that about 60 mg of zinc a day for up to 10 weeks lowered a marker of copper status.
Low copper can cause real problems. ODS lists anemia, loss of skin or hair color, high cholesterol, bone problems, loss of coordination and a higher risk of infection among the signs of copper deficiency.
| Daily amounts for adults | Zinc | Copper |
|---|---|---|
| RDA, men | 11 mg | 900 mcg |
| RDA, women | 8 mg | 900 mcg |
| Upper limit | 40 mg | 10,000 mcg |
| AREDS2 formula (NEI) | 80 mg | 2 mg (2,000 mcg) |
Sources: ODS zinc and copper fact sheets (adult rows, which cover older adults) and NEI. The copper upper limit is based on liver damage, and the formula's 2 mg is well below it.
ODS also notes that overusing zinc-containing denture creams for years has caused copper deficiency and nerve problems. If you use denture cream and take zinc, mention both to your doctor.
Reading the zinc on a label
Supplement labels list elemental zinc, which is the actual amount of zinc, not the weight of the whole compound. The ODS zinc fact sheet also notes a few details about absorption:
- In young adults, about 61% of zinc is absorbed from zinc citrate or zinc gluconate, and about 50% from zinc oxide.
- Taking 25 mg or more of iron at the same time can lower zinc absorption.
- The AREDS results come from zinc oxide and cupric oxide, which the American Academy of Ophthalmology also lists for the AREDS2 formula.
If a label uses a different form of zinc than the trials did, your pharmacist can help you compare the amounts.
Food sources of zinc and copper
Here are top food sources of each mineral, as listed in the ODS fact sheets:
| Food | Zinc | Food | Copper |
|---|---|---|---|
| Oysters, Eastern, farmed, raw, 3 oz | 32 mg | Beef liver, pan fried, 3 oz | 12,400 mcg |
| Oysters, Pacific, cooked, 3 oz | 28.2 mg | Oysters, eastern, wild, cooked, 3 oz | 4,850 mcg |
| Beef, bottom sirloin, roasted, 3 oz | 3.8 mg | Baking chocolate, unsweetened, 1 oz | 938 mcg |
| Blue crab, cooked, 3 oz | 3.2 mg | Potato, cooked with skin, 1 medium | 675 mcg |
| Oats, cooked with water, 1 cup | 2.3 mg | Cashews, dry roasted, 1 oz | 629 mcg |
Food can help with everyday needs, but it is not a practical way to reach the trial dose. The NEI FAQ says the high levels in the AREDS formulas are difficult to get from diet alone. Learn more in Can You Get AREDS2 Nutrients From Food?
Safety points to discuss with your doctor
High-dose zinc has known side effects. The ODS zinc fact sheet lists nausea, dizziness, headaches, stomach upset, vomiting and loss of appetite as signs of too much zinc. The 2023 Cochrane review found that stomach and bowel symptoms were the main reported side effect of these supplements. In AREDS, zinc was linked to a higher risk of genitourinary problems in men, but AREDS2 saw no difference between the high and low zinc doses.
Zinc can also interact with some medicines, including certain antibiotics (quinolones such as ciprofloxacin, and tetracyclines), penicillamine, and thiazide diuretics. For the antibiotics, ODS advises taking the antibiotic at least 2 hours before or 4 to 6 hours after zinc. Copper, by contrast, has no known clinically relevant drug interactions, according to ODS.
Keep in mind: If you take a water pill, an antibiotic, an iron supplement or a multivitamin, talk with your doctor or pharmacist before adding a high-dose zinc formula. Bring your bottles so they can check the total amounts. Our article on AREDS2 safety, side effects and interactions covers this in more depth.
If you are comparing formulas, our science page lists the doses used in the trials.
Related reading
- Nutrition and Eye Health: What the Research Actually Shows
- The AREDS and AREDS2 Trials Explained
- 5 Vitamins and Nutrients That Matter for Your Eyes
- Are AREDS2 Vitamins Safe? Side Effects and Interactions
- AREDS2 Supplements Compared by Label
References
- Age-Related Eye Disease Study Research Group. AREDS Report No. 8. Arch Ophthalmol. 2001;119(10):1417-1436. doi:10.1001/archopht.119.10.1417
- Age-Related Eye Disease Study 2 Research Group. Lutein + zeaxanthin and omega-3 fatty acids for age-related macular degeneration: the Age-Related Eye Disease Study 2 (AREDS2) randomized clinical trial. JAMA. 2013;309(19):2005-2015. doi:10.1001/jama.2013.4997
- Chew EY, Clemons TE, Agrón E, et al. Long-term outcomes of adding lutein/zeaxanthin and omega-3 fatty acids to the AREDS supplements on age-related macular degeneration progression: AREDS2 report 28. JAMA Ophthalmol. 2022;140(7):692-698. doi:10.1001/jamaophthalmol.2022.1640
- Evans JR, Lawrenson JG. Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration. Cochrane Database Syst Rev. 2023;9:CD000254. doi:10.1002/14651858.CD000254.pub5
- NIH Office of Dietary Supplements. Zinc: Fact Sheet for Health Professionals. Updated January 6, 2026. ods.od.nih.gov
- NIH Office of Dietary Supplements. Copper: Fact Sheet for Health Professionals. Updated October 18, 2022. ods.od.nih.gov
- National Eye Institute. About AREDS and AREDS2. Updated October 22, 2025. nei.nih.gov
- National Eye Institute. AREDS/AREDS2 Frequently Asked Questions. Updated November 19, 2020. nei.nih.gov
- American Academy of Ophthalmology. Vitamins for AMD. Published August 19, 2026. aao.org
This article is for general education and is not medical advice. Talk with your eye doctor before starting any supplement, especially if you smoke, take other medicines, or have a health condition. These statements have not been evaluated by the Food and Drug Administration. TruVista products are not intended to diagnose, treat, cure, or prevent any disease.
