Nutrition 101: Copper

Copper is a trace mineral that functions as a coenzyme in many physiologic reactions.

Recomme​n​ded Intakes

The Dietary Reference Intakes (DRI) for copper are shown below:

What Does ​Copper Do?

Copper is a structural component of many enzyme systems and allows iron to function in the body. Copper is a component of ceruloplasmin, a protein necessary for the transport of iron. Ceruloplasmin also acts as an enzyme, catalyzing the oxidation of minerals including iron. As a result, the presence of copper helps to prevent iron deficiency anemia

Copper protects against free radicals by acting as an antioxidant. Superoxide dismutase is a copper-dependent enzyme that fights the damage caused by free radicals. When not enough copper is present, the activity of superoxide dismutase is diminished, and the damage to cell membranes caused by superoxide radicals increases.

Copper is required for the health of bones, connective tissue, lungs, and blood vessels. Copper is a component of an enzyme that participates in the synthesis of collagen and elastin, two important structural proteins found in bone and connective tissue. Copper is also involved in the production of melanin, the pigment that gives hair and skin their color. It is also important for the production of thyroxine, the thyroid hormone, and is necessary for the synthesis of phospholipids found in myelin sheaths that cover and protect nerves. Copper also plays a role in wound healing by helping blood to clot.

Copper needs are very minimal, and it is easy to meet the requirements for copper by eating a varied diet. Our bodies adapt so that people with low dietary copper intakes absorb more copper than people with high dietary intakes.

Top Copper-Rich Foods

Foods high in copper include beans, fish, liver, shellfish, whole grains, cocoa powder, cereal and cereal products, and green vegetables. The amount of copper in plants is not affected by the copper content of the soil they grow in.

Nutrition Facts Label and t​he % Daily Value

In the United States: The % daily value gives you an idea of how much copper is in the food you eat. The daily value for copper is 2,000 mcg, which is much higher than the DRI for all age groups but much lower than the upper limit for adults. The number you see on the Nutrition Facts label is a percentage calculated by dividing the amount of copper in one serving of the food by the DV. Using an example from the above table, 1/4 cup of cashews containing 800 mcg of copper would have 40% of the DV for copper. The FDA does not require that the % daily value for copper be listed on the Nutrition Facts label.

In Canada: The daily value for copper is 2,000 mcg, which again is much higher than the DRI for all age groups but much lower than the upper limit. Listing the daily value for copper on the Nutrition Facts label is optional.

Nutrient Interactions

Zinc: Excessive zinc supplementation can cause deficiency of copper.

Iron: High iron intake can interfere with copper absorption in infants.

Carolyn Berry, RD

Alumni: University of British Columbia – Carolyn Berry is a Vancouver-based Registered Dietitian, self-proclaimed foodie, marathon runner, and owner of Berry Nourished. Carolyn works in a variety of areas including clinical nutrition, outpatient counselling at Medisys Preventive Health Clinic, as a nutrition tour leader with Save-On-Foods, and in the media, including segments on CBC Television, CKNW and Spice Radio. Through informative and practical nutrition advice and her food-first approach to health, Carolyn fulfills her passion to empower others with knowledge about nutrition so that they can make the best decisions to improve their health. She strongly believes that food should be both healthful and delicious.