Copper

Copper is a trace element: you need little of it, but without it things go wrong. It sits in a handful of enzymes with big jobs. One makes iron usable, so that it ends up in your red blood cells; without copper an anaemia develops that looks like iron deficiency but does not respond to iron. One makes collagen and elastin firm, in your blood vessels, your bones and your skin. One clears free radicals, and one protects the insulation around your nerves. Copper is in shellfish, nuts, seeds, whole grains, cocoa and liver. Most of the copper in your blood, roughly nine parts in ten, is bound to ceruloplasmin, a protein your liver makes. That makes the copper value a double measurement: it says something about your copper and something about that protein. Ceruloplasmin rises with inflammation, in pregnancy and with oestrogen, so with the pill too, and then lifts the copper with it without you having more copper. The other way round, a low copper with a low ceruloplasmin is the trail to Wilson's disease, in which copper actually accumulates in liver and brain. Your report shows copper in µmol/L. Normal is about 12 to 20.1 µmol/L where the labs overlap. It is drawn in a special tube, because ordinary tubes can shed traces of metal.

The reason copper is interesting for anyone who wants to stay healthy lies in zinc. Zinc and copper compete for the same uptake in the gut, and plenty of zinc sets the gut cells to holding on to copper and disposing of it. Anyone who takes a high dose of zinc for months, against colds, for the skin or for testosterone, can develop a copper deficiency that way without ever thinking of it. That starts with tiredness and an anaemia that does not respond to iron, and can grow into numbness in the feet and an unsteady feeling when walking that looks like a B12 deficiency. A copper value beside a zinc value shows whether the supplement has gone too far. The second group is everyone in whom the uptake falters: after stomach surgery, with coeliac disease or a chronic gut inflammation, and in anyone who eats one-sidedly for a long time. Here too anaemia and nerve symptoms are the first signs, and here too it is reversible as soon as you see it. The third reason is rare but too important to miss: Wilson's disease, an inherited condition in which the liver cannot get rid of copper and it accumulates in liver and brain. That gives a low copper value and a low ceruloplasmin, often in a young adult with unexplained liver values, tremor or mood symptoms. Untreated it is serious, treated it is very manageable, and it starts with these two values side by side.

A high copper is usually the transport protein and not the copper itself. In order of how often it occurs: an inflammation, because ceruloplasmin is an acute-phase protein; the pill or other oestrogens; a pregnancy; and rarely a liver disease in which bile does not drain properly. A high copper with a high ceruloplasmin and a high CRP is therefore an inflammation, not a copper matter. Too much copper from food or water hardly ever occurs. A low copper means too little supply, a faltering uptake, too much zinc, or a low ceruloplasmin. In order: a low ceruloplasmin, which pulls the copper down with it; plenty of zinc as a supplement; stomach surgery or gut disease; and rarely Wilson's disease. A low copper with a low ceruloplasmin in a young person with liver values or neurological symptoms is the combination you do not want to miss. Always read copper beside ceruloplasmin, and beyond that beside zinc, CRP, ferritin and your blood count, and keep to one and the same lab when comparing over time.