Can a copper deficiency cause hair thinning/loss and miniaturization? Degrading the hair shaft? Brittle fine hair?

Copper deficiency may cause hair thinning and a lack-luster appearance. More commonly, it causes a decrease rate of hair growth. Excess copper can also cause hair loss. The copper/zinc ratio is key and one may need Zinc supplements.
Jeff Rapaport MD FAAD
Realself Hall of Fame

sure it’s possible. However, if you have a copper deficiency that is truly sufficient to cause hair loss, most patients would be at least somewhat ill (or have other medical issues of note). Individuals with Menkes syndrome in particular have a number of systemic issues. In addition to sparse hair, children with Menkes syndrome are often unwell. Children don’t gain weight properly, have several neurological issues including seizures and poor muscle tone and many die in early childhood. Adults with copper deficiency should not compare themselves to children with Menkes as the two are very different. Generally speaking, most minor degrees of copper deficiency in adults is not sufficient to cause hair loss. However, if you are worried, you should, of course see your physician for a full physical examination and exploration of further blood tests. Total copper levels are generally in the range 10-22 μmol/L or 63.7-140.12 μg/dL. Copper levels just below this cut off usually have little consequence but your doctors can look into this in greater detail. Isolated copper deficiency that is to sufficient magnitude to cause hair loss is not common. Minor amounts of copper deficiency can occur but that’s a different situation than major copper deficiency. Other mineral abnormalities often go along with copper abnormalities in most adult patients and deficiencies of copper and deficiencies/excesses of other minerals should be given proper medical attention and a full medical evaluation is needed. One of the most common causes of minor degrees of copper deficiency amongst hair loss patients is excessive use of zinc supplements. Zinc intake dramatically lowers the levels of copper in the blood. Please see your doctors if concerned so that a proper evaluation can be done. In 99.9 % of patients I see with minor copper deficiency, the deficiency is unrelated to the hair loss issue.