Copper deficiency happens when your body lacks enough of this essential trace mineral to make red blood cells, white blood cells and healthy nerve tissue. The main signs are anemia, low white blood cell counts (neutropenia), numbness, and an unsteady walk. It develops slowly, over months to years, and it is often mistaken for vitamin B12 deficiency. A common cause is taking too much zinc. Blood tests for serum copper and ceruloplasmin confirm it, and adults need 900 mcg of copper a day, easily found in shellfish, nuts, seeds and organ meats.
What Copper Does in Your Body
An adult body holds only 50–120 mg of copper, and almost two-thirds of it sits in the skeleton and muscle. That small amount powers copper-dependent enzymes (cuproenzymes) involved in energy production, iron metabolism, connective tissue synthesis, neurotransmitter synthesis, pigmentation and immune function. Copper-containing superoxide dismutases provide most of the body’s defense against oxidative damage. Copper also helps maintain the myelin sheaths that insulate your nerves.
The most important link to symptoms is ceruloplasmin. This enzyme carries more than 95% of the copper in healthy blood plasma and plays a key role in iron metabolism. That is why low copper can cause anemia.
Signs and Symptoms of Copper Deficiency
The symptoms of copper deficiency fall into two groups: blood and nerves. You can have one group without the other.
- Blood changes: anemia and neutropenia are typical. Unlike B12 deficiency, low platelets (thrombocytopenia) are rare. The anemia can be microcytic, normocytic or macrocytic, meaning red blood cells may be small, normal or large. B12 deficiency always produces the large-cell (megaloblastic) type.
- Nerve damage: myelopathy (spinal cord dysfunction) is the most common neurological sign. It closely mimics the spinal cord damage seen in B12 deficiency. Peripheral neuropathy can cause numbness and tingling in your hands and feet. Ataxia, meaning uncoordinated movement, can make walking difficult.
- General signs: fatigue and frequent infections.
- Other effects: hypopigmentation (loss of skin and hair color), high cholesterol, connective tissue disorders and osteoporosis.
See a doctor if you have unexplained fatigue, repeated infections, or tingling and balance problems that keep getting worse. This matters even more if you take zinc supplements or have had gastric bypass surgery.
What Causes Copper Deficiency
Copper deficiency is more common in women and in people aged 50–70. Dietary intake is often lower than you might expect. In national survey data, 6–15% of US adults who don’t take copper supplements fall below the Estimated Average Requirement (EAR) of 700 mcg a day. One review puts the share of North American adults below the EAR at more than 25%.
Zinc: The Overlooked Culprit
Excess zinc is one of the most common causes. High zinc intake makes intestinal cells produce metallothionein, a protein that traps copper inside the gut lining so it never reaches your blood. The risk rises with zinc supplements above 40 mg/day, long-term use, high doses, and zinc-containing denture adhesives. Zinc-induced copper deficiency can cause anemia and neutropenia, which weakens immune defenses, so more zinc is not always better for immunity. Early diagnosis matters because the nerve damage may become permanent.
Surgery and Malabsorption
- Bariatric surgery: after Roux-en-Y gastric bypass in particular, about 9–10% of patients develop copper deficiency.
- Gut disorders: celiac disease and inflammatory bowel disease reduce copper absorption.
- Total parenteral nutrition without added copper, for example after bowel resection or gastrectomy.
Menkes Disease
Menkes disease is an inherited, X-linked disorder of copper transport, so it affects mostly boys. It causes severe deficiency in infancy, with seizures, slow growth, floppy muscles and kinky, crinkly hair. It is usually fatal. Copper treatment started within the first 4 weeks of life may improve symptoms and extend lifespan.
How Copper Deficiency Is Diagnosed
If copper deficiency is suspected, doctors should order serum copper, ceruloplasmin and zinc tests at the same time. A complete blood count and a vitamin B12 test help rule out B12 deficiency, which looks very similar.
| Test | Normal range | Suggests deficiency |
|---|---|---|
| Serum copper | 10–25 µmol/L (63.5–158.9 mcg/dL) | Below 12 µmol/L; below 7.9 µmol/L = severe |
| Ceruloplasmin | 180–400 mg/L | Below 0.2 g/L (200 mg/L) |
| Serum zinc | Ordered alongside | High levels point to zinc as the cause |
One catch: inflammation, pregnancy, birth control pills and the seizure drug valproic acid can raise ceruloplasmin. That can hide a real deficiency and produce a falsely normal result.
How Copper Deficiency Is Treated
- Fix the cause. Stop excess zinc or treat the malabsorption.
- Mild to moderate deficiency: oral copper prescribed by a doctor, plus more copper-rich foods, until blood levels normalize.
- Severe deficiency (serum copper below 7.9 µmol/L): copper given by IV first, then by mouth, and referral to a hematologist or neurologist.
Anemia and neutropenia usually resolve within weeks. In one reported case, about 6 weeks of oral copper cured the anemia behind a patient’s fatigue. Myelopathy may not reverse, which is why early diagnosis matters. Your doctor sets the dose and checks your levels; the upper limit for healthy people does not apply to treatment under medical supervision. Don’t start high-dose copper supplements on your own.
Foods High in Copper
The recommended dietary allowance for adults is 900 mcg a day, which is also the Daily Value on food labels. US men average about 1,400 mcg and women about 1,100 mcg from food. Your gut also adapts: copper absorption is about 75% when intake is low (400 mcg/day) and falls to 12% when intake is high (7.5 mg/day).
| Food | Serving | Copper | % DV |
|---|---|---|---|
| Beef liver, pan-fried | 3 oz (85 g) | 12,400 mcg | about 1,380% |
| Eastern oysters, cooked | 6 oysters | 3,800 mcg | 419% |
| Alaskan king crab | 1 leg | about 1,580 mcg | 176% |
| Lobster, cooked | 3 oz | about 1,310 mcg | 146% |
| Shiitake mushrooms, cooked | 1 cup | 1,300 mcg | 144% |
| Sesame seeds, toasted | 1 oz | 700 mcg | 78% |
| Cashews, dry roasted | 1 oz (28 g) | 600 mcg | 70% |
| Chickpeas, cooked | 1 cup | 600 mcg | 64% |
| Sunflower seeds, dry roasted | 1 oz | about 520 mcg | 58% |
| Dark chocolate (70–85% cocoa) | 1 oz (28 g) | 500 mcg | 56% |
Wheat-bran cereals and other whole grains are also good sources. A handful of cashews plus a cup of chickpeas covers more than the daily target. One serving of beef liver alone exceeds the adult upper limit of 10 mg, so eat organ meats only occasionally.
Too Much Copper: Toxicity and Wilson Disease
Copper toxicity is rare in healthy people. Chronic high exposure causes abdominal pain, cramps, nausea, vomiting, diarrhea and liver damage. In severe cases it can lead to liver failure and neuropsychiatric symptoms. One real-world source is water that has sat in copper pipes; the EPA’s limit for public water is 1.3 mg/L. The adult upper limit is 10 mg/day from food and supplements combined. For children it is lower: 1 mg (ages 1–3), 3 mg (4–8), 5 mg (9–13) and 8 mg (14–18).
Frequently Asked Questions
Can copper deficiency cause headaches?
Possibly, but headache is not a classic sign. More frequent migraines have been reported, likely because copper affects nerve signaling and neurotransmitters. Some case reports also describe headaches alongside fatigue and sensory symptoms. See a doctor for frequent or new headaches.
Does copper deficiency cause gray hair?
Copper is needed for pigmentation, and hypopigmentation is a recognized effect of deficiency. Menkes disease causes kinky, crinkly hair. However, ordinary age-related graying is not listed among the typical signs of copper deficiency, so it is no reason to take copper supplements on your own.
What is Wilson disease?
Wilson disease is a rare inherited disorder caused by a mutation in the ATP7B gene, affecting about 1 in 30,000 to 50,000 people. The body can’t clear copper, so it builds up to toxic levels in the liver and brain. This can cause hepatitis, cirrhosis, liver failure, mood changes, depression or psychosis. Doctors diagnose it using low ceruloplasmin, high 24-hour urine copper, copper rings in the cornea (Kayser-Fleischer rings) and family history. Treatment is lifelong, with chelating drugs such as penicillamine or trientine, or high-dose zinc acetate, which uses zinc’s copper-blocking effect on purpose.
Should I take copper supplements on my own?
Not without testing. On average, US adults get more than the 900 mcg RDA from food. If you have symptoms, take zinc, or have had gut surgery, ask your doctor for serum copper, ceruloplasmin and zinc tests before you supplement.
