Copper – Building a Strong, Resilient Body

Copper is an essential trace mineral that works as a cofactor in a small number of critical enzyme systems — but those systems cover energy production, iron transport, connective tissue strength, and neurotransmitter production. The body contains only about 50–120mg of copper in total, mostly in the muscles, bones, and liver. Despite those tiny amounts, copper is indispensable, and copper deficiency is often missed — because its anaemia can be mistaken for iron deficiency, and its nerve damage for vitamin B12 deficiency.

Key Mechanisms

Ceruloplasmin and iron mobilization: one of copper’s most important roles is one most people have never heard of. Ceruloplasmin is the main copper-carrying protein in the blood, and it’s also a ferroxidase — an enzyme that converts iron from its ferrous form (Fe²⁺) to its ferric form (Fe³⁺). That conversion is needed for iron to load onto transferrin, the protein that carries iron around the body. A related copper enzyme (hephaestin) does the same job in the gut when iron is absorbed. Without enough copper, iron gets stuck in storage and in the gut lining, however much iron is present. That’s why copper deficiency causes an anaemia that can be mistaken for iron deficiency — and why iron supplements alone don’t fix it.

Cytochrome c oxidase: copper is an essential part of Complex IV of the mitochondrial electron transport chain — the enzyme that combines electrons with oxygen to form water in the final step of aerobic respiration. This step helps generate the gradient that drives ATP production. Without copper, aerobic energy production in cells is impaired.

Lysyl oxidase and connective tissue: the enzyme lysyl oxidase needs copper to cross-link collagen and elastin fibers. Cross-linking gives tendons, ligaments, blood vessel walls, skin, and bone their strength. Without copper, collagen is still made but stays structurally weak.

Superoxide dismutase (SOD): copper and zinc together form copper-zinc SOD, one of the body’s main antioxidant enzymes, which neutralizes superoxide radicals produced during normal metabolism and exercise.

RDA (Recommended Dietary Allowance)

* Adequate Intake (AI) for infants. Source: US National Academies, via the NIH Office of Dietary Supplements. The daily value used on food labels is 0.9mg (900µg).

ODA (Optimal Daily Allowance)

Meet the RDA — 900µg a day for adults — from food, with intakes of around 1,000–1,500µg (1–1.5mg) being typical and reasonable. Most people who eat nuts, seeds, whole grains, legumes, or shellfish get this easily. The group that most needs to pay attention is people taking zinc supplements for months at a time — for them, making sure copper intake is adequate, through food or a zinc product that includes 1–2mg of copper, is the key step. There’s no evidence that copper intakes well above this range bring extra benefits.

Found In (per 100g)

Liver and other organ meats are exceptional copper sources — beef liver is even higher than lamb liver, at over 12mg per 85g (3oz) serving according to the NIH. That’s more than the 10mg upper limit in a single serving, so, as with its very high vitamin A content, liver is best eaten occasionally rather than daily. For those who don’t eat organ meats, shellfish, nuts, seeds, dark chocolate, and mushrooms are the most practical sources — dried shiitake mushrooms are much more concentrated than cooked ones. Homes with copper water pipes can also add some copper to drinking water, especially when water has been standing in the pipes.

Helps With

• Iron transport and red blood cell formation, via ceruloplasmin
• Aerobic energy production, through cytochrome c oxidase in the mitochondria
• Building and maintaining strong connective tissue — tendons, ligaments, blood vessel walls, and skin — via lysyl oxidase
• Antioxidant defense, through copper-zinc superoxide dismutase (SOD)
• Immune function and white blood cell production
• Neurotransmitter production — copper is needed for dopamine β-hydroxylase, the enzyme that converts dopamine to noradrenaline
• Brain development and nervous system health
• Skin and hair pigment — copper is needed for tyrosinase, the enzyme that makes melanin
• Bone strength

For Athletes and Active People

Copper matters for athletes mainly through three pathways — and one practical risk.

Energy production: as part of cytochrome c oxidase, copper sits at the final step of aerobic respiration, and copper-dependent iron transport supports the red blood cells that carry oxygen. Severe depletion can impair endurance capacity — rare in well-nourished athletes, but it’s the mechanism that matters.

Connective tissue: copper-dependent cross-linking gives tendons and ligaments their load-bearing strength. Collagen synthesis gets a lot of attention in sports nutrition (vitamin C, glycine, gelatin), but the cross-linking step that makes collagen structurally useful requires copper. Adequate copper is part of the nutritional foundation for connective tissue, though there’s no evidence that extra copper prevents injuries in athletes who aren’t deficient.

Oxidative stress: intense training increases oxidative stress, and copper-zinc SOD is one of the body’s main internal defenses — both minerals are needed for it to work.

The zinc supplement risk: this is the most practical point for most athletes. Zinc supplements are popular for testosterone, immune support, and recovery, and long-term zinc supplementation reduces copper absorption, through the mechanism explained on our zinc page. In studies, around 50–60mg of zinc a day for several weeks lowered markers of copper status, and serious copper deficiency has been reported with long-term high intakes. Athletes taking zinc for months are the group most at risk of copper depletion, so choose zinc products that include copper, or make sure your diet supplies plenty.

Insufficient Doses

Deficiency risk is higher in:

• People taking high-dose zinc long-term without copper — including from overuse of zinc-containing denture creams. This is one of the most common causes of acquired copper deficiency.
• People who’ve had weight-loss surgery, particularly gastric bypass — copper deficiency is a recognized long-term complication, sometimes appearing years later
• Premature babies — who are born with low copper stores and grow rapidly
• People with malabsorption conditions, such as coeliac disease or Crohn’s disease
• People on long-term intravenous nutrition without enough copper
• Children with Menkes disease — a rare inherited disorder of the copper transport protein ATP7A, causing severe copper deficiency from birth regardless of diet

Symptoms of deficiency:

• Fatigue and weakness
• Anaemia that doesn’t respond to iron supplements — the red blood cells may be small, normal-sized, or large, unlike typical iron deficiency
• Low white blood cell count (neutropenia) — a key clue that distinguishes copper deficiency from iron deficiency, and a cause of frequent infections
• Nerve damage: numbness, tingling, poor coordination, and an unsteady walk — copper deficiency myelopathy closely mimics vitamin B12 deficiency, and may not fully recover even after copper is restored
• Weaker bones and higher fracture risk
• Pale skin and loss of hair pigment
• Poor wound healing
• In animal studies, weakened blood vessel walls and heart problems

The nerve symptoms of copper deficiency are often misdiagnosed as B12 deficiency or multiple sclerosis. Doctors are advised to check copper in anyone with unexplained spinal cord or nerve problems — especially if they have a history of zinc supplementation or weight-loss surgery.

Excessive Doses

Upper limit (UL): 10mg (10,000µg) a day for adults, from food and supplements combined. The limits for children are lower:

Source: US National Academies, via the NIH Office of Dietary Supplements.

Copper toxicity from food is rare in healthy people — the liver controls copper levels by excreting the excess into bile. Toxicity is most likely from contaminated drinking water (for example, acidic water standing in copper pipes), excessive supplementation, or genetic disorders.

Wilson’s disease: a genetic condition caused by faults in the ATP7B gene, which the liver needs to excrete copper into bile. Copper builds up in the liver, brain, kidneys, and eyes. A characteristic sign is Kayser-Fleischer rings — greenish-brown copper deposits around the edge of the iris. Wilson’s disease needs lifelong medical treatment, with medicines that remove copper (such as penicillamine or trientine) or zinc to block its absorption, along with dietary changes.

Symptoms of copper excess:

• Nausea, vomiting, abdominal pain, and diarrhea
• Metallic taste in the mouth
• Liver damage and jaundice with prolonged high intake
• Neurological and psychiatric changes in severe cases
• Haemolytic anaemia (destruction of red blood cells) in severe poisoning

Different Types

Copper supplements are most often needed not for their own sake but as a counterbalance to zinc. In that context, most well-absorbed forms at 1–2mg do the job, and many zinc products already include copper.

• Copper Bisglycinate / Glycinate — copper bound to the amino acid glycine; well absorbed and generally well tolerated. A popular choice for daily use.
• Copper Gluconate — widely available, well absorbed, and common in multiminerals.
• Copper Citrate — well absorbed and budget-friendly.
• Copper Picolinate — well absorbed; less common.
• Copper Sulfate — well absorbed and widely used in supplements and medically; it can cause nausea in some people, especially on an empty stomach.
• Copper Oxide (cupric oxide) — common in inexpensive multivitamins, but animal studies suggest it’s poorly absorbed. Not a good choice if you need reliable copper intake.

Which form for your goal:

How to Take It

Most copper supplementation is driven by zinc use. If you take zinc supplements for months — particularly around 25mg a day or more — choose a product that includes 1–2mg of copper, or add a separate copper supplement. Taking zinc and copper together in the same product is fine: zinc’s effect on copper builds up over weeks, as the gut lining adapts, so spacing the doses apart doesn’t prevent it. What matters is keeping zinc doses moderate and copper intake adequate.

Take copper with food to reduce the risk of nausea. Very high doses of vitamin C (several grams a day) may reduce copper absorption, so take them at different times if you use both.

Don’t exceed 10mg a day from all sources combined — and remember that a single serving of beef liver can provide more than that.

If you have Wilson’s disease, or a family history of copper disorders, don’t take copper supplements without medical advice.

Interactions

Long-term high-dose zinc is the main antagonist of copper absorption, and the most common cause of copper depletion outside of medical settings. Penicillamine and trientine bind copper and are used to treat copper overload in Wilson’s disease. High intakes of molybdenum reduce copper absorption — molybdenum compounds have even been studied as copper-lowering treatments. Very high doses of iron supplements may also reduce copper absorption, mainly a concern in infants.

Synergy

• Works with iron, through ceruloplasmin and hephaestin, to move iron into the blood and build red blood cells — the two minerals depend on each other for healthy blood.
• Works with zinc in copper-zinc superoxide dismutase (SOD) for antioxidant defence — and the two need to stay in balance.
• Works with vitamin C in collagen formation — vitamin C is needed to build stable collagen molecules, and copper-dependent lysyl oxidase then cross-links them for strength.
• Complements manganese in antioxidant defence — manganese SOD protects the mitochondria, while copper-zinc SOD works in the rest of the cell.

Antagonistic Interactions

• Long-term high-dose zinc reduces copper absorption, through metallothionein in the gut lining — the most important interaction.
• Very high fructose intakes worsened copper deficiency in animal studies; the relevance for people is unclear.
• Severe copper poisoning can destroy red blood cells, causing anaemia.
• Molybdenum forms complexes with copper (thiomolybdates) that reduce its absorption and availability.

Food values: USDA FoodData Central — lamb liver, braised (SR Legacy, FDC ID 172532); eastern oysters, wild, cooked, moist heat (SR Legacy, 171980); Pacific oysters, cooked (SR Legacy, 174250); cashews, raw (Foundation Foods, 2515374); sunflower seeds, raw (Foundation Foods, 2515381); dark chocolate, 70–85% cacao (SR Legacy, 170273); Brazil nuts, raw (Foundation Foods, 2515373); northern lobster, cooked (SR Legacy, 174209); hazelnuts, raw (Foundation Foods, 2515375); pumpkin seeds (pepitas), raw (Foundation Foods, 2515380); Alaska king crab, cooked (SR Legacy, 174202); almonds, raw (Foundation Foods, 2346393); shiitake mushrooms, cooked (SR Legacy, 168437); peanuts, raw (Foundation Foods, 2515376); chickpeas, cooked (SR Legacy, 173757); spinach, boiled (SR Legacy, 168463). Beef liver figure from the NIH Office of Dietary Supplements. RDA and upper limits from the US National Academies, via the NIH Office of Dietary Supplements. % Daily Values use the FDA’s current Daily Value of 0.9mg.