Copper
Copper is recorded richest in our database in liver at 14 mg per 100 grams, with oysters at 4.8 mg, sesame seeds at 4.08 mg and cashews at 2.2 mg. The European reference intake is 1 mg per day (EU NRV) — the smallest daily value of any mineral on this site.
The authorised wordings about copper
Regulation (EU) No 432/2012 holds for copper, among others: "copper contributes to normal iron transport in the body", "copper contributes to the protection of cells from oxidative stress" and "copper contributes to normal energy-yielding metabolism". That first sentence explains why copper and iron always surface near each other in the literature: the two minerals work in the same system, and a story about one is rarely complete without the other.
Where copper comes from in the data
Per 100 grams: liver 14 mg, oysters 4.8 mg, sesame seeds 4.08 mg, cashews 2.2 mg and sunflower seeds 1.8 mg. Set those figures beside a reference intake of 1 mg and the picture is unusual: virtually every product in the top five covers the daily value in a normal portion. Twenty grams of cashews nearly suffices on its own. That is exceptional compared with most other minerals on this site. Just behind them sit dark chocolate with 85 percent cocoa at 1.77 mg, Brazil nuts at 1.74 mg and hazelnuts at 1.73 mg. Four products thus land within a tenth of a milligram of one another.
1 mg a day, the smallest reference in the set
The EU NRV of 1 mg per day makes copper a trace element in the most literal sense. Nuts, seeds, wholegrain cereals, cocoa and shellfish supply it broadly, so the daily value is nearly always reached on normal food. That is also why you rarely see copper singled out on a label: it is usually simply there, and paying attention to it yields little in practice.
Where the interplay with zinc comes from
Copper and zinc partly share the same absorption mechanism, so a sustained very high zinc intake from supplements can affect copper status. That is one of the few genuine reasons for restraint with standalone high-dose zinc, and it is an argument you rarely hear in the trade. We mention it here because it is a concrete, checkable fact rather than a marketing story.
Our approach: no product, but a structure
We run no supplement line and hold no preferred brand. For copper that is an easy position: on a varied diet the subject barely arises. What we do fix in a programme is a set daily portion of nuts or seeds. That single habit covers copper, magnesium, zinc and fibre in one action, and it is easy to sustain on a working day with little room.
How we compile this list
We sort every row in the DCRAFT food database on the measured value per 100 grams and take the top of that list. Rows recorded per piece, per slice or per portion do not count, because a value per piece cannot be compared with a value per 100 grams. Products listed under a brand name are left out: their composition changes outside our control, and a ranking resting on it ages without us noticing. Where several products carry precisely the same value, it comes from one shared row in our source data and we name one product from that group. We set this rule out here because a ranking without a visible selection rule is an opinion rather than a measurement.
Frequently asked questions
Which foods contain the most copper?
Liver leads at 14 mg per 100 grams, with oysters at 4.8 mg and sesame seeds at 4.08 mg.
How much copper per day?
The EU NRV sets the daily value at 1 mg. That is the smallest daily value of any mineral in our knowledge base.
Why are copper and iron mentioned together?
Because Regulation (EU) No 432/2012 carries the wording that copper contributes to normal iron transport in the body. The two minerals work in the same system.
Does a zinc supplement affect copper status?
Copper and zinc partly share an absorption mechanism, so a sustained very high zinc intake can affect copper status. Discuss that with a doctor.
Sources
- DCRAFT food database — KILLER COACH ENGINE V2.3 workbook (accessed 26 August 2026)
- EU NRV — Regulation (EU) No 1169/2011, Annex XIII (accessed 26 August 2026)
- Regulation (EU) No 432/2012 (accessed 26 August 2026)
Please note: This is general information about nutrition, not medical advice. If you have symptoms or suspect a deficiency, discuss it with your doctor. We do not sell supplements and have no commercial interest in any brand.
Last updated: .
Written by Dennis, founder of Dcraft Of Fitness.