Copper (as copper bisglycinate chelate)

What is copper?

Copper is an essential trace mineral that the body needs in small amounts. It is part of several enzymes involved in energy production, iron metabolism, the formation of connective tissue and the pigment melanin, and the body’s antioxidant defenses. Good food sources include shellfish, organ meats, nuts, seeds, whole grains, beans and dark chocolate. Most people get enough copper from a normal diet. In supplements it appears as cupric oxide, copper gluconate, copper sulfate or chelated forms such as copper bisglycinate.

What the research says

Copper’s main role in eye supplements is protective. Zinc and copper compete for absorption in the gut, and taking high doses of zinc for long periods can lower copper levels and cause anemia. That is why the AREDS and AREDS 2 formulas, developed by the National Eye Institute for people with intermediate age-related macular degeneration, include 2 mg of copper alongside zinc. The trials tested the complete formula, not copper by itself, so there is no evidence that copper on its own benefits the eyes.

MedlinePlus notes that a lack of copper may lead to anemia and osteoporosis, and that in large amounts copper is poisonous. People with Wilson disease, a rare inherited disorder, cannot clear copper properly and accumulate it in the liver, brain and other organs; they must avoid copper supplements. Deficiency is uncommon but can occur after some weight loss surgeries, with certain malabsorption conditions, or with long-term high-dose zinc.

How it’s used in supplements

Copper is found in many multivitamins at about 0.5 to 2 mg, and in eye formulas that contain zinc. The 2 mg used in AREDS 2 is about twice the RDA but is a commonly used supplemental amount. Copper supplements can cause nausea or stomach upset, especially on an empty stomach. Because copper also comes from food, multivitamins and some water pipes, people taking more than one supplement should add up their intake. Anyone with liver disease or Wilson disease should not take copper unless a doctor recommends it.

When you read an eye supplement label, the copper line is a useful quality check. A formula that contains a meaningful dose of zinc but no copper may, over months, nudge copper levels down, while one that pairs them follows the logic of the National Eye Institute trials. On its own, though, copper is a supporting nutrient rather than an active eye ingredient, and there is no reason for people with a normal diet to seek out extra copper for their vision. Signs of low copper, such as unexplained anemia, fatigue or numbness in the hands and feet, should be evaluated by a doctor rather than self-treated.