(posted by Hopkins Technology)
This is one in a series of fact sheets containing information to help you select foods that provide
adequate daily amounts of vitamins, minerals, and dietary fiber as you follow the Dietary Guidelines
The Guidelines are -
- Eat a Variety of Foods
- Maintain Desirable Weight
- Avoid Too Much Fat, Saturated Fat, and Cholesterol
- Eat Foods with Adequate Starch and Fiber
- Avoid Too Much Sugar
- Avoid Too Much Sodium
- If You Drink Alcoholic Beverages, Do So in Moderation
HOW MUCH COPPER SHOULD WE GET?
Adults (18 years and older)
The daily U.S. Recommended Daily Allowance (RDA) is 900 micrograms for adults; 1,000 micrograms
for pregnant women; 1,300 micrograms for nursing women; and 890 micrograms for adolescents
14-18 years old. Surveys suggest that most Americans consume less than the RDA for copper each
day. Up to 10,000 micrograms daily appears to be safe for consumption in adults. Vegan diets
appear to provide adequate amounts of copper.
In a number of clinical trials copper doses of 2-10 milligrams by mouth were safely used in
patients. For plaque inhibition, a 1.1mM copper rinse has been used for four days. The appropriate
application of ointment preparations containing copper in concentrations up to 20% has also been
studied with no apparent toxic effects.
Children (younger than 18 years)
The daily U.S. Recommended Daily Allowance (RDA) for children is 890 micrograms for adolescents
14-18 years old; 700 micrograms for children 9-13 years old; 440 micrograms for children 4-8 years
old; 340 micrograms for children 1-3 years old; 220 micrograms for infants 7-12 months old;
and 200 micrograms for infants 0-6 months old. Surveys suggest that most Americans consume less
than the RDA for copper each day. Up to 3,000-5,000 micrograms daily appears to be safe for
consumption in children.
Copper deficiency may occur in infants fed only cow-milk formulas (which are relatively low in copper
content) or synthetic low lactose diets, premature/low-birth weight infants, infants with prolonged
diarrhea or malnutrition, malabsorption syndromes (including celiac disease, sprue, or short bowel
syndrome), cystic fibrosis, or during intravenous total parenteral nutrition (TPN) or other restrictive
diets. Such situations may merit copper supplementation (and other trace elements), which should be
under the supervision of a healthcare professional. In the United States, copper is not available in
Management of marasmus should be under the supervision of a healthcare professional,
although 20-80 micrograms per kilogram per day of copper sulfate supplementation by mouth
has been reported as safe.
An allergic skin reaction, called contact dermatitis, has occurred in some people after exposure
to copper sulfate.
WHAT IS MEANT BY A GOOD FOOD SOURCE?
A good food source of copper contains a substantial amount of copper in relation to its calorie
content and contributes at least 10 percent of the U.S. Recommended Dietary Allowance (U.S. RDA)
for copper in a selected serving size.
The U.S. RDA for copper is the amount of the mineral used as a standard in nutrition labeling of foods.
This allowance is based on the 1968 estimate of need made by the Food and Nutrition Board of the National
Academy of Sciences. The 1989 range of Estimated Safe and Adequate Intakes for adults is 1.5 to 3
milligrams per day.
Copper is a mineral that occurs naturally in many foods, including vegetables, legumes, nuts,
grains, and fruits, as well as shellfish, avocado, and beef (organs such as liver). Because copper
is found in the earth's crust, most of the world's surface water and ground water used for drinking
purposes contains small amounts of copper.
In 1985 and 1986, 29 percent of the copper in the diets of women was supplied by grain
products and 26 percent was furnished by fruits and vegetables. Of the fruits and vegetables, white
potatoes provided more copper than any of the other types. Foods that contain small amounts of copper
but are not considered good sources can contribute significant amounts of copper to an individual's
diet if these foods are eaten often or in large amounts.
WHY DO WE NEED COPPER?
Copper, a mineral, is necessary (along with iron) for the formation of hemoglobin. It also helps keep
bones, blood vessels, and nerves healthy.
Copper is involved in numerous biochemical reactions in human cells. Copper is a component of
multiple enzymes, is involved with the regulation of gene expression, mitochondrial function/cellular
metabolism, connective tissue formation, as well as the absorption, storage, and metabolism of iron.
Copper levels are tightly regulated in the body.
As many as 9.1 million people will have age-related macular degeneration (AMD) in 2010. The easiest
and cheapest intervention is a special vitamin/mineral combination (vitamins C, E, beta carotene,
zinc and copper) that may slow the progression of AMD.
See Evidence for Copper Usage below.
DO WE GET ENOUGH COPPER?
According to recent USDA surveys, the average intake of copper by women 19 to 50 years of age was about
1 milligram, and that of men of the same age was about 1.6 milligrams. For women, this amount is less
than the 1.5- to 3-milligram range of Estimated Safe and Adequate Daily Dietary Intakes recommended by
the Food and Nutrition Board of the National Academy of Sciences.
Copper toxicity is rare in the general population. Wilson's disease is a genetic disorder in
which the body cannot rid itself of copper, resulting in deposition in organs and serious consequences
such as liver failure and neurologic damage. Obstruction of bile flow, contamination of dialysis
solution (in patients receiving hemodialysis for kidney failure), Indian childhood cirrhosis, and
idiopathic copper toxicosis are other rare causes of potentially dangerous excess copper levels.
Such individuals should be followed closely by a physician and nutritionist.
Copper deficiency can occur in infants fed only cow-milk formulas (which are relatively low in copper
content), premature/low-birth weight infants, infants with prolonged diarrhea or malnutrition,
individuals with malabsorption syndromes (including celiac disease, sprue, or short bowel syndrome),
cystic fibrosis, in the elderly, or those receiving intravenous total parenteral nutrition (TPN) or
other restrictive diets.
HOW CAN WE GET ENOUGH COPPER?
Eating a variety of foods that contain copper is the best way to get an adequate amount. Healthy
individuals who eat a balanced diet rarely need supplements. Intakes of copper tend to be low in
relation to recommendations, and there aren't that many foods that are really good sources; thus,
it may take special care to ensure an adequate intake. The list of foods will help you select
those that are good sources of copper as you follow the Dietary Guidelines. The list of good sources
was derived from the nutritive value of foods tables used to analyze information for recent food
consumption surveys of the U.S. Department of Agriculture, Human Nutrition Information Service.
HOW TO PREPARE FOODS TO RETAIN COPPER
Copper is lost in cooking some foods even under the best conditions. To retain copper:
- Cook foods in a minimal amount of water.
- Cook for the shortest possible time.
WHAT IS A SERVING?
The serving sizes used on the list of good sources are only estimates of the amounts of food you
might eat. The amount of nutrient in a serving depends on the weight of the serving. For example,
1/2 cup of cooked mushrooms contains more copper than 1/2 cup of mushrooms served raw, because a
serving of cooked mushrooms weighs more. Therefore, cooked mushrooms appear on the list while the
raw form does not. Raw mushrooms provide the nutrient - but just not enough in a 1/2-cup serving
to be considered a good source.
WHAT ARE GOOD SOURCES OF COPPER?
FOOD SELECTED PERCENTAGE SERVING SIZE U.S. RDA (1)
BREADS, CEREALS, AND OTHER GRAIN PRODUCTS
Barley, cooked 2/3 cup ++
English muffin, whole-wheat 1 +
Muffin, bran 1 medium +
Pita bread, whole-wheat 1 small +
Prunes, dried, cooked, unsweetened 1/2 cup +
Beans, lima, cooked 1/2 cup +
Mushrooms, cooked 1/2 cup +
Potato, baked or boiled, with skin 1 medium +
Sweetpotato, baked or boiled 1 medium +
Tomato juice cocktail 3/4 cup +
Turnip greens, cooked 1/2 cup +
MEAT, POULTRY, FISH, AND ALTERNATES
Meat and Poultry
Beef or calf 3 ounces +++
Chicken or turkey 1/2 cup diced +
Fish and Seafood
Clams; steamed, boiled, or
canned; drained 3 ounces +
Crabmeat, steamed 3 ounces ++
Lobster, steamed or boiled 3 ounces +++
Baked, broiled, or steamed 3 ounces +++
Canned, undrained 3 ounces +++
Shrimp; broiled, steamed,
boiled, or canned; drained 3 ounces +
Dry Beans, Peas, and Lentils
Beans, black-eyed peas (cowpeas),
or soybeans, cooked 1/2 cup +
Lentils, cooked 1/2 cup +
Nuts and Seeds
Almonds or cashews,
roasted or dry-roasted 2 tablespoons +
Brazil nuts, english walnuts,
filberts (hazelnuts), pine
nuts (pignolias) 2 tablespoons +
Mixed nuts, dry-roasted 2 tablespoons +
Peanuts, roasted 2 tablespoons +
Pistachio nuts, unroasted 2 tablespoons +
Pumpkin or squash seeds,
hulled, roasted 2 tablespoons +
Sesame seeds 2 tablespoons +
Sunflower seeds, hulled;
roasted, dry-roasted, or
unroasted 2 tablespoons +
(1) A selected serving size contains -
+ 10-24 percent of the U.S. RDA for adults and children over 4 years of age
++ 25-39 percent of the U.S. RDA for adults and children over 4 years of age
+++ 40 percent or more of the U.S. RDA for adults and children over 4 years of age
EVIDENCE FOR COPPER USAGE
These uses have been tested in humans or animals. Safety and effectiveness have not always
been proven. Some of these conditions are potentially serious, and should be evaluated by a
qualified healthcare provider.
|Uses of Copper based on scientific evidence||Grade*
Copper deficiency may occur in infants fed only cow-milk formulas (which are relatively
low in copper content), premature/low-birth weight infants, infants with prolonged diarrhea
or malnutrition, individuals with malabsorption syndromes (including celiac disease, sprue,
or short bowel syndrome), individuals with cystic fibrosis, in the elderly, or in those receiving
intravenous total parenteral nutrition (TPN) or other restrictive diets. Such individuals may
require supplementation with copper (and other trace elements).
|Age-related macular degeneration
There is not enough scientific evidence available to determine if copper plays a role in this
|Alzheimer's disease prevention
Conflicting study results report that copper intake may either increase or decrease the risk
of developing Alzheimer's disease. Additional research is needed before a recommendation can be
The use of copper bracelets in the treatment of arthritis has a long history of traditional use,
with many anecdotal reports of effectiveness. There are research reports suggesting that copper
salicylate may reduce arthritis symptoms more effectively than either copper or aspirin alone.
Further study is needed before a firm recommendation can be made.
Preliminary research reports that lowering copper levels theoretically may arrest the progression
of cancer by inhibiting blood vessel growth (angiogenesis). Copper intake has not been identified
as a risk factor for the development or progression of cancer.
|Cardiovascular disease prevention / atherosclerosis
The effects of copper intake or blood copper levels on cholesterol, atherosclerosis (cholesterol
plaques in arteries), or coronary artery disease remain unclear. Studies in humans are mixed, and
further research is needed in this area.
|Childhood growth promotion
Severe copper deficiency may retard growth. Adequate intake of micronutrients including copper and
other vitamins may promote growth as measured by length gains.
|Dental conditions (protecting enamel and plaque prevention)
Laboratory studies have shown that copper may help protect tooth enamel (the outer layer of the teeth).
However, early human research suggests that copper may not be effective.
|Immune system function
Copper is involved in the development of immune cells and immune function in the body. Severe copper
deficiency appears to have adverse effects on immune function, although the exact mechanism is not
Copper deficiency may occur with marasmus, and supplementation with copper may play a role in the
nutritional treatment of infants with this condition. Infants with marasmus should be managed by a
qualified healthcare professional.
|Menkes' kinky-hair disease
Menkes' kinky-hair disease is a rare disorder of copper transport/absorption. Copper supplementation
may be helpful in this disease, although further research is necessary before a clear recommendation
can be made.
|Metabolic disorders (trimethylaminuria)
Trimethylaminuria (TMAU) is a metabolic disorder characterized by the inability to oxidize and
convert dietary-derived trimethylamine (TMA) to trimethylamine N-oxide (TMAO). Preliminary evidence
suggests that the use of copper chlorophyllin results in a reduced urinary-free TMA concentration
and normalization of TMAO. Further research is required in this field before a strong recommendations
can be made.
|Osteoporosis / osteopenia
Osteopenia and other abnormalities of bone development related to copper deficiency may occur in
copper-deficient low-birth weight infants and young children. Supplementation with copper may be
helpful in the treatment and/or prevention of osteoporosis, although early human evidence is conflicting.
The effects of copper deficiency or copper supplementation on bone metabolism and age-related osteoporosis
require further research before clear conclusions can be drawn.
Some studies of schizophrenic patients report high blood copper levels with low urinary copper
(suggesting that copper is being retained), and low blood zinc levels. In some of these cases,
zinc was observed to be helpful as an anti-anxiety agent. The role of copper supplementation is
Copper deficiency is one of the causes of sideroblastic anemia that should be considered when
evaluating this condition, particularly when the anemia is unresponsive to iron therapy alone.
This anemia appears to be caused by defective iron mobilization due to decreased ceruloplasmin
Copper has been used to reduce wrinkles and skin appearance following laser skin resurfacing.
Currently, there is not enough scientific evidence to make recommendations for or against this
|Systemic lupus erythematosus (SLE)
A preliminary study suggests that copper offers no benefit to individuals with SLE. Further research
is required before recommendations can be made.
|Neural-tube defect prevention
The risk of neural-tube defects is decreased in women who take folic acid and multivitamins
during the periconception period. Supplementation with trace-elements alone, such as copper,
does not appear to prevent these defects.
*Key to grades
A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use;
F: Strong scientific evidence against this use.