The nutrients required for a healthy body are divided into macronutrients (carbohydrates, protein and fat) and micronutrients (vitamins and minerals). Both are necessary for the proper function of the organism. The micronutrients, however, are needed only in small doses. Minerals, like most vitamins, are not synthesized by the body and therefore must be obtained from food or dietary supplements. Minerals are essential for the synthesis and maintenance of structures or tissues, play a regulatory role in the metabolism, control nerve impulses, muscle activity and acid-base balance of the body.