Copper
Essential trace element, usually measured in the blood as serum copper
Also known as
Definition
Copper is an essential trace element that the body cannot make on its own and takes in through food. It is part of several enzymes involved in energy production, iron metabolism, connective tissue and nerve messengers. Normally, more than 95% of the copper in the blood is bound to the transport protein ceruloplasmin. Copper is usually measured in serum, often together with ceruloplasmin and copper in urine.
| Parameter | Value |
|---|---|
| Unit | µmol/L (µg/dL) |
| Reference Range | Adults: typically 10–25 µmol/L (about 64–159 µg/dL). Labs may differ; the reference range in your own report is what counts. Discuss your results with your doctor. |
Agree on your personal target range with your doctor.
1 µmol/L equals about 6.35 µg/dL (molar mass of copper: 63.55 g/mol).
↓ What a low value means
Copper deficiency is uncommon in humans. Low levels may be linked to malnutrition or poor absorption in the gut, for example in celiac disease, to very high zinc intake from supplements, which can impair copper absorption, and to the rare inherited Menkes syndrome. Copper deficiency may be accompanied by anemia, a reduced number of neutrophils and osteoporosis, among other things. A single value is not a diagnosis; discuss deviations with your doctor.
↑ What a high value means
Blood copper can be influenced by estrogen, pregnancy, infection, inflammation and some cancers, so a higher value is not always a sign of disease. Copper toxicity is rare in healthy people without an inherited disorder of copper balance; it has been described, for example, from drinking water that has stood for a long time in copper pipes. In the rare inherited Wilson disease, the body cannot remove extra copper, and it builds up in the liver, brain and other organs. Interpretation is up to your doctor.
When to test
Copper is usually measured together with ceruloplasmin and, if needed, copper in urine: when symptoms or findings point to a disorder of copper balance, with a family history of Wilson disease even without symptoms, and to monitor known copper disorders. Ask your lab whether it has specific requirements for the blood draw.
Frequently asked questions
Where does the body get copper from? +
The body cannot make copper itself and takes it in through food. According to MedlinePlus, good sources include oysters and other shellfish, whole grains, beans, nuts, potatoes, organ meats, dark leafy greens, dried fruit and cocoa. Most people get enough copper from their diet.
What does zinc have to do with copper? +
High zinc intake from food can interfere with copper absorption in the gut, and excessive use of zinc supplements can lead to copper deficiency. If you take zinc, mention it when you discuss your results with your doctor.
Why is copper often measured together with ceruloplasmin? +
Normally, more than 95% of the copper in the blood is bound to ceruloplasmin. Both values together, often supplemented by copper in urine, give a more complete picture of copper balance than a single value. For a diagnosis, your doctor also considers symptoms, medical history and family history.
Can hormones or inflammation change the copper value? +
Yes. Estrogen, pregnancy, infection and inflammation can influence blood copper. Mention such factors when your blood is drawn so your result can be interpreted correctly.
Copper
Sources
Last updated: October 05, 2026
This information is for orientation only and does not replace medical advice. Reference ranges can vary by laboratory, method and country.