Copper
An essential trace element for iron metabolism, energy production, collagen formation and nervous system function, whose balance with zinc is crucial.
Copper is a cofactor for many enzymes: energy production (the mitochondrial respiratory chain), iron metabolism (it helps mobilise iron), collagen and elastin synthesis (tissues, blood vessels), pigmentation, neurotransmitters and antioxidant defence (superoxide dismutase).
The original angle (the hidden link with iron and zinc): copper is often the “missing link” in problems blamed on iron. A copper deficiency can cause anaemia that does not respond to iron supplementation! This is because copper is needed to incorporate iron into haemoglobin. Treating an “iron shortage” without considering copper may fail.
The zinc/copper balance (crucial): zinc and copper are antagonists for absorption. Prolonged supplementation with high-dose zinc (common for immunity or skin) can cause a copper deficiency, with neurological and haematological consequences. It is a classic trap of zinc self-medication. The zinc/copper ratio needs to stay balanced.
Sources: offal (liver), shellfish (oysters), nuts and seeds, cocoa/dark chocolate, pulses, mushrooms.
Isolated deficiency is rare: a purely dietary copper deficiency is rare (food provides enough), but it occurs in specific contexts: zinc over-supplementation, bariatric surgery, malabsorption. Excess copper is also possible (Wilson’s disease, which is genetic) and toxic.
Copper and ageing: its role in collagen and elastin links it to the health of skin and blood vessels. A deficiency can weaken connective tissue.