No RDA; the Reference Nutrient Intake is 1.2 mg.
Copper is an essential trace mineral.
It is distributed all over the body, but more is in the bone, muscles, brain, heart and kidneys.
The amount absorbed through the skin when wearing copper bracelets is fairly small and not thought to be harmful.
Where do you get copper?
We get it from a range of foods such as whole grains, seafood, liver, pulses, nuts and potatoes. (Flour refining removes 70% of the copper.) Copper water pipes have been the source of much of our copper, although plastic is replacing copper.
Copper is needed by the immune system for fighting infections. It is involved in iron absorption and haemoglobin production: it is a co-factor in many enzymes: it also has a role in nerve transmissions in the brain.
Too much copper
Copper poisoning is rare, but relatively small amounts in excess of normal levels are toxic to human sperm, (hence its use in contraceptive coils).
Too little copper
Lack of copper is not a common problem provided our diet is reasonable.
The body controls the amount of copper absorbed and excreted. Proper absorption needs a balance with iron, cobalt, manganese, molybdenum and vitamin C. Copper competes with zinc for the same pathway. And iron and copper deficiency seem to be associated.
Supplements of copper alone are unnecessary and may be harmful. Balanced multi-vitamin and minerals are the best way to get extra copper, (after dietary methods).