the aim of this review was to discuss aspects that involve metabolic and functional alterations of copper in diabetes mellitus. in this disease some functional disturbances of copper have been explained by alterations in the processes of absorption, circulation and utilization of this element. the hormone status can modify the biliary secretion of copper and therefore to reflect on homeostatic regulation of the absorption. impaired lysil oxidase activity (a kind of cuproenzyme) alters elastin and collagen synthesis and this damages the integrity of the blood vessel. this fact can worsen the development of the vascular alterations in diabetic patients. researches with experimental diabetes indicate high concentrations of copper in kidneys. this leads to speculations about the genesis of the diabetic nephropathy. human studies demonstrate that diabetic patients have abnormal circulation of copper, lipid peroxidation increased and inadequate nutritional status of this micronutrient.