How much copper do you need per day?

The RDA for copper is 900 mcg a day for adults aged 19 and over.

These are the reference amounts used on US food labels and in dietary guidance, not personal targets. What you need shifts with age, pregnancy, medication and health conditions. The % Daily Value shown on every food page here is calculated against the FDA Daily Value for copper, which is 0.9 mg a day.

What this means for you

Nine hundred micrograms is a small target and ordinary food clears it without anyone noticing. A cup of sesame seeds carries over six times the daily amount, cashews about three times, and shellfish, liver, nuts, whole grains and dark chocolate all contribute.

So the honest answer to "how much copper do I need" is that the number is rarely the problem. What causes copper deficiency in practice is not a poor diet.

Not for everyone. High-dose zinc supplements taken for months, and zinc-containing denture creams used heavily, block copper absorption well enough to produce a real deficiency. It shows up as anaemia that iron does not fix, along with unsteadiness and repeated infections.

The safe upper limit is 10,000 micrograms a day, more than ten times the requirement, and food does not approach it. Copper is also one of the few nutrients with no known clinically relevant interactions with medicines, so there is no timing to arrange.

If you eat a normal mixed diet and take no zinc, you can close this page.

Two findings put the daily number in context. Copper supplements have been tested for the thing they are usually sold for and did nothing: five randomised trials in 176 people found total cholesterol, LDL and HDL unchanged. And the deficiency, when it happens, is serious. In a review of 198 published cases of spinal cord damage from copper deficiency, the two commonest causes were stomach surgery and swallowing too much zinc. Food covers the requirement. A zinc habit can undo it.

Most people are already there

Established. The median American copper intake is 0.94 mg a day, and 1.00 mg among adults, against a recommendation of 0.9 mg and a ceiling of 10 mg. The fifth percentile of adults sits at 0.41 mg and the 95th at 2.37 mg. Almost nobody is anywhere near the ceiling, and most people land within a rounding error of the target without planning anything.

Two ceilings, and why they differ

The 10 mg figure is American and rests on liver injury. Europe published a different kind of number. Copper is not expected to accumulate in the body up to about 5 mg a day, and the safe level works out at 0.07 mg per kilogram of body weight, roughly 4.9 mg for a 70 kilogram adult. Both are population figures rather than personal thresholds. A page that quotes one without naming the regulator has skipped the interesting part.

How fast food crosses them

One 85 gram slice of beef liver carries about 12.3 mg of copper by American data. That is past both ceilings and roughly thirteen times the daily recommendation, from one serving. Liver is also the food where national tables disagree most, so treat any single figure as a rough guide. Chicken liver at 0.57 mg per 100 g is in a different league, and within the British table raw liver runs from 0.50 mg per 100 g in chicken to 20.48 in calf.

The thing that changes your copper more than dinner does

Zinc. Four weeks of zinc acetate at 50 mg three times a day, the standard Wilson disease regimen, cut the copper in the livers of healthy people to 56 per cent of where it started, and zinc gluconate on the same schedule to 49 per cent. Two caveats sit beside that. The measurement itself shifted by about a fifth from one day to the next in the same person, and five of 37 participants showed no response to any zinc schedule. And in 21 trials covering nearly 4,000 children on ordinary doses of 10 to 20 mg a day, haemoglobin did not fall the way the copper theory predicted. After heart surgery, where doses run higher, blood copper was significantly lower on the third day and back level by week three. If you take zinc for months, the bottle is setting your copper more than your diet is.

Written from the evidence cards and the data on this page, then checked back against the sources. Bioma Learn has no human medical reviewer at this time and we say so rather than invent one. Information, not medical advice. How we verify.

Foods highest in copper on this site

• Sesame seeds, whole, dried — 5.88 mg per 1 cup (653% DV)
• Cashew nuts, dry roasted — 3.04 mg per 1 cup, halves and whole (338% DV)
• Cashew nuts, oil roasted — 2.64 mg per 1 cup, whole (293% DV)
• Mixed nuts, oil roasted, without peanuts — 2.58 mg per 1 cup (287% DV)
• Sunflower seed kernels, oil roasted — 2.44 mg per 1 cup (271% DV)

All copper sources ranked →

Full guide: Copper: the mineral most people only hear about when zinc goes wrong