Here I’m going to answer some of the most common questions I get from vegans about the mineral Copper. Some of the themes overlap because some of the most frequently asked questions ask more or less the same thing, just in different ways. So you may want to use the table of contents to go right down to the content that interests you.
Anyway, without further ado.
Is Copper Vegan?
Yes, unlike some nutrients such as vitamin D, copper is found in numerous plant foods including whole grains, legumes, nuts, and starchy tubers.1
Are Copper Supplements Vegan?
Yes, unlike some minerals which can be sourced from animals (e.g. calcium derived from bone meal), copper is extracted from the earth. The mineral is usually extracted as copper sulfides from large pit mines. The mineral is found abundantly in various locations throughout the world.2
Is Copper Chlorophyllin Vegan?
Copper chlorophyllin is considered vegan. It is simply copper (a mineral extracted from the earth) and chlorophyllin—a semi-synthetic derivative of chlorophyll (the green pigment found in plants).
What About Beauty Products (Copper Peptide Serums, etc.)?
Copper peptides (used in serums) can be derived from animals* but are usually synthesized in a lab. They are considered vegan if the amino acids used in synthesizing the peptides are not derived from animal sources. To know for sure, you will have to check with individual manufacturers.
*They’re found in trace amounts in saliva, blood plasma, and urine.
Do Vegans Need Copper Supplementation?
Most healthy individuals, including vegans, needn’t supplement with copper. Certain conditions, as well as long-term excessive zinc supplementation, can reduce copper absorption to the point of inducing deficiency. But most healthy people consuming varied diets (omnivorous or plant-based) are not at risk for deficiency of this nutrient.
Copper sulfate is the main form of copper you’ll find in supplements and mineral-fortified food products. Cupric oxide can be found in some supplements as well, however, the use of this form as a source of the mineral is discouraged as it’s been shown to be largely unavailable for absorption from the GI tract. For this reason, it’s no longer used to fortify animal nutrition.3
Aside from copper sulfate (∼25% copper), other bioavailable forms of the mineral include:3
- Cupric acetate (~35% copper)
- Copper carbonate (∼57%)
- Cupric chloride (∼47%)
A Note on Zinc-Copper Supplements
Zinc and copper intakes need to be kept in balance. For this reason, many copper supplements are paired with zinc—to ensure proper ratios of the two minerals. Zinc has a potent effect on copper absorption. For example, zinc supplementation at 110–165 mg taken for 10 months had a negative effect on copper status.4
Further, discontinuation of the zinc supplements combined with 2 months of oral copper supplementation fell short of correcting copper deficiency. It took intravenous cupric chloride administration for 5 days in order to bypass the intestinal cells to correct the deficiency.
It works both ways. It’s often been speculated that lower zinc intakes characteristic of vegan diets may lead to long-term elevations in copper levels among this population. See copper toxicity for more on this.
Copper in Plant-Based Diets
The bioavailability of copper from plant-based sources may be limited, but the relative abundance of the mineral in the plant kingdom more than makes up for this shortcoming.5
The copper content of plant-based food can vary widely, depending on the origin of the food and the conditions in which the food was cultivated, produced, prepared, and handled. As you’ll see in the section on vegan sources of copper, the mineral is widely distributed in the plant kingdom including nuts, seeds, legumes, dried fruit, potatoes, cocoa and whole grains.6
One study measured the copper and zinc content of 74 foods via atomic absorption spectrophotometry. Each was reported to be consumed by practicing vegetarians. Plant sources—namely, legumes, nuts, seeds, and whole grains—were deemed by the researchers as “excellent” sources of copper.5
Fruits and veggies were shown to have less of the mineral but consisted of a few notable sources.
How Much Copper Do Vegans Need?
Vegan copper needs are the same as for the general population.
The body re-uses endogenous copper in a process that contributes to the body’s copper homeostasis. Recommendations take into account copper from endogenous sources (namely, digestive juices) that are absorbed from the GI tract. The copper contents of gastric juice and saliva, for example, are ∼1,000 μg and ~400 μg, respectively. Pancreatic and duodenal juices contain as much as 2,200 μg and 1,300 μg, respectively.7
The body needs about 700 μg of exogenous copper. This number was derived from depletion and repletion studies, and analysis of obligatory losses over a range of dietary intakes. After accounting for a 30% coefficient of variation, the adult RDA for copper comes to 900 μg/day.8 Recommendations go up a bit during pregnancy and lactation and are set at 1,000 μg and 1,300 μg, respectively.8
What Are the Symptoms of Copper Deficiency?
Numerous clinical manifestations have been associated with copper deficiency. The most commonly recognized symptoms include:9
- Anemia. We won’t go into it here, but copper deficiency results in iron becoming trapped within cells resulting in secondary iron-deficiency anemia
- Neutropenia (abnormally few neutrophils)
- Impaired immune function
- Depigmentation or hypopigmentation of skin and hair
- Impaired cholesterol metabolism
- Bone abnormalities
- Pulmonary and cardiovascular dysfunction
What Dietary Factors Influence the Bioavailability of Copper?
Source: adapted from Gropper, Sareen S.; Smith, Jack L.. Advanced Nutrition and Human Metabolism (Page 512).
Also, the mineral molybdenum is known to enhance copper excretion.10
Are Vegans Commonly Deficient in Copper? Do They Have Low Copper Levels?
Vegans are not characteristically deficient in copper. According to Winston J. Craig and Laura Pinyan in Vegetarian Nutrition Volume 3, vegetarian diets (in general) typically contain substantial amounts of copper as well as potassium, magnesium, manganese, folic acid, fiber, vitamins A, C, E, and K.11
Non-meat-eating vegetarians (as opposed to pescatarians) have little advantage over vegans when it comes to copper intake, as milk and dairy products tend to be poor sources of the mineral. The median adult copper intake from foods in the US ranges from ~ 1,000 to 1,600 μg per day.8 Vegetarian and vegan intakes would be expected to be similar if not higher.12
Which Groups Are at Risk of Copper Deficiency?
Folks at higher risk of copper deficiency include:13
- Those supplementing with excessive amounts of zinc (40 mg/day or more).
- Those using certain medications for prolonged periods of time. For example, proton pump inhibitors (PPIs) are known to diminish copper absorption.
- Those with conditions promoting increased loss of the mineral from the body. For example, GI malabsorptive disorders such as Crohn’s disease, ulcerative colitis, and celiac disease are known to increase copper losses from the body resulting in a greater risk of deficiency.
What Vegan Foods Contain Copper?
The best vegan sources of copper include:
- Nuts. For example, 1 oz of cashews contains 0.6 mg or 31% DV.14
- Potato. 1 large contains 0.4 mg or 20% DV.15
- Mushrooms. ½ cup provides 0.8 mg or 20% DV.16
- Cocoa powder. 1 oz. provides 1.0 mg or 50% DV.17
- Lemon, raw. 1 lemon provides 0.3 mg or 14% DV.18
- Asparagus. 1 cup has 0.3 mg or 13% DV.19
High Copper Foods Suitable for Raw Vegans
Nuts are perhaps the best source of copper for raw vegans. Tree nuts, in general, are among the best sources of copper vegans and vegetarians. Since they can be eaten in their raw state, they provide a dense source of the nutrient for raw vegans. Raw mushrooms also constitute a great source of the mineral for this diet group. Other sources include seeds, lemons, and mushrooms.16,18
Copper Toxicity: Do Vegans Get Too Much?
Copper toxicity is uncommon in most populations, and vegans are no exception. It’s been speculated that copper toxicity may be a problem for vegans due to the characteristically low zinc intake of this population. However, no evidence exists showing that vegans are particularly susceptible to copper toxicity. After all, the richest sources of the mineral are meats, organ meats (especially liver) and shellfish (especially lobster and oysters).
The main population at risk for copper toxicity are those with the inherited condition, Wilson’s Disease—a genetic disorder of copper metabolism, wherein defective biliary copper excretion leads to copper toxicity. When acute poisonings occur, water contamination is usually the culprit. A Tolerable Upper Intake Level (TUL) for the mineral has been set at 10 mg* per day.8
Intakes at this level would cause excessive buildup of the mineral over time. Symptoms of copper toxicity induced by prolonged high intakes of the mineral include:
- Kidney damage evident by oliguria or anuria (little and no urine production, respectively).20
- Hematuria (the presence of blood in the urine).20
- Liver damage resulting in jaundice. Chronic ingestion of 30 mg copper/day for 2 years with subsequent 60 mg/day for 1 year led to liver failure in an otherwise healthy man who self-prescribed copper supplementation.20,21
*Although, this is the level of copper ingestion known to be toxic, lower intakes (~5mg) can cause GI discomfort in some folks.
Acute copper toxicity (as in water contamination and excessive supplementation) is induced by large intakes of the mineral at once. Specifically, 64 mg of elemental copper (about 250 mg of copper sulfate) can cause acute poisoning.
Symptoms of acute copper toxicity include:20,22
- GI problems—epigastric pain, diarrhea, nausea, and vomiting
- Weakness and lethargy
- Death—copper is known to be lethal in amounts upwards of 1,000 times the normal dietary intake
Vegans with Copper IUDs/Coils
I’ve seen a few questions on the web about whether vegans can use copper IUDs. Some folks want to know if it’s ethical, and others wonder if it’s healthy.
As for the ethical question, copper IUDs are completely suitable for vegans. I think the question comes from the fact that the device is spermicidal. Like bacteria, sperm are technically alive in a crude biological sense, but don’t contain a nervous system, and thus aren’t considered sentient in any meaningful way.
As for the health question, vegan women often wonder whether the combination of lower zinc intakes (characteristic of vegans) combined with copper IUDs may pose a risk of copper toxicity. After all, zinc is needed to balance out copper levels in the body. First of all, zinc intakes needn’t be poor when following plant-based diets. Secondly, studies have shown copper IUDs to exert little to no effect on serum levels of the mineral.23,24
- Copper in Diet: Medlineplus Medical Encyclopedia https://medlineplus.gov/ency/article/002419.htm
- Hammond, C.R. (2004). The Elements, in Handbook of Chemistry and Physics (81st ed.). CRC press. ISBN 978-0-8493-0485-9.
- Baker DH. Cupric oxide should not be used as a copper supplement for either animals or humans. J Nutr. 1999; 129:2278–79.
- Hoffman H, Phyliky R, Fleming C. Zinc-induced copper deficiency. Gastroenterology. 1988; 94:508–12.
- Freeland-Graves JH, Ebangit ML, Bodzy PW. Zinc and copper content of foods used in vegetarian diets. J Am Diet Assoc. 1980 Dec;77(6):648-54. https://www.ncbi.nlm.nih.gov/pubmed/7440859
- Gropper, Sareen S.; Smith, Jack L.. Advanced Nutrition and Human Metabolism (Page 510).
- Linder M, Hazegh-Azam M. Copper biochemistry and molecular biology. Am J Clin Nutr. 1996; 63:S797–811.
- Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes. Washington, DC: National Academy Press. 2001 pp. 224–57.
- de Romana DL, Olivares M, Uauy R, Araya M. Risks and benefits of copper in light of new insights of copper homeostasis. J Trace Elem Med Biol. 2011; 25:3–13.
- Turnlund J. Copper nutriture, bioavailability, and the influence of dietary factors. J Am Diet Assoc. 1988; 88:303–08.
- Joan Sabaté-Rosemary; Ratzin-Turner. (2001). Vegetarian Nutrition. Page 265. CRC Press. ISBN 0-8493-8508-3.
- Rauma AL, Mykkänen H. Antioxidant status in vegetarians versus omnivores. Nutrition. 2000 Feb;16(2):111-9.
- Gropper, Sareen S.; Smith, Jack L.. Advanced Nutrition and Human Metabolism (Page 518).
- Nuts, Cashew Nuts, Raw Nutrition Facts & Calories https://nutritiondata.self.com/facts/nut-and-seed-products/3095/2
- Potato, Flesh and Skin, Raw Nutrition Facts & Calories https://nutritiondata.self.com/facts/vegetables-and-vegetable-products/2546/2
- Mushrooms, Cooked, Boiled, Drained, with Salt Nutrition Facts & Calories https://nutritiondata.self.com/facts/vegetables-and-vegetable-products/2872/2
- Cocoa, Dry Powder, Unsweetened, Processed with Alkali [dutch Cocoa] Nutrition Facts & Calories https://nutritiondata.self.com/facts/sweets/5472/2
- Lemons, Raw, with Peel Nutrition Facts & Calories https://nutritiondata.self.com/facts/fruits-and-fruit-juices/1937/2
- Asparagus, Raw Nutrition Facts & Calories https://nutritiondata.self.com/facts/vegetables-and-vegetable-products/2311/2
- Chuttani H, Gupta P, Gulati S, Gupta D. Acute copper sulfate poisoning. Am J Med. 1965; 39:849–54.
- O’Donohue J, Reid M, Varghese A, et al. Micro-nodular cirrhosis and acute liver failure due to chronic copper self-intoxication. Eur J Gastroenterol Hepatol. 1993; 5:561–62.
- Bremner I. Manifestations of copper excess. Am J Clin Nutr. 1998; 67(suppl):S1069–73.
- Prema K, Lakshmi BA, Babu S. Serum copper in long-term users of copper intrauterine devices. Fertil Steril. 1980 Jul;34(1):32-5.
- Taper LJ, Hinners ML, Ritchey SJ. Effects of zinc intake on copper balance in adult females. Am J Clin Nutr. 1980 May;33(5):1077-82. https://www.ncbi.nlm.nih.gov/pubmed/7369156