Here’s another warrior in the battle against heart disease, yet two out of three of us get less than the recommended minimum of 1.5 to 3 milligrams a day. Serious copper deficiency, although rare, can raise cholesterol and blood pressure and lead to problems with maintain heart rhythms. Also, like zinc, it plays an important role in the function of the immune system, making sure that T-cells and antibodies are working optimally. You get copper from nuts, peas and beans, fruits, oysters and shellfish.