Like manganese, copper is an essential trace mineral that has only recently been found to play an important role in bone health maintenance. This role is still not fully understood, but we do know that by virtue of a copper-containing enzyme called lysyl oxidase, copper aids in the formation of collagen for bone and connective tissue and contributes to the mechanical strength of bone collagen fibrils — the long thin strands of proteins that cross-link to one another in the spaces around cells.
Copper also helps inhibit bone resorption through a copper- and zinc-containing antioxidant called superoxide dismutase. This antioxidant neutralizes superoxide radicals produced by the bone-breakdown cells called osteoclasts during bone resorption.
Again, as with manganese, inadequate copper levels have been associated with the development of osteoporosis. And as with so many other minerals, copper excretion from the body is increased on a diet high in sugar, other sweeteners like fructose, and refined flour. Some researchers have suggested that even lactose (milk sugar) could interfere with copper metabolism, making high dairy intake less than ideal for copper utilization. With our penchant for sugar, refined flour, and dairy, it’s not surprising that copper is among the minerals most often deficient in the American diet.