Diagnosis of trace metal deficiency--with emphasis on copper and zinc.

A method of diagnosing trace metal deficiency is proposed. Measurement of an appropriate metalloprotein before and after administration of a physiological replenishment dose of the metal should distinguish low levels due to metal deficiency from those due to other mechanisms. Serum ceruloplasmin is the logical protein for copper assessment; serum alkaline phosphatase and red cell carbonic anhydrase should be considered for zinc.