Minerals are found in plants and animals. These elements promote chemical reactions and may form part of many tissues. Calcium, phosphorus, potassium, iron,  sodium, sulphur, chlorine, and magnesium are important for health.
Some mineral elements are required in very tiny amounts in human diets for metabolic purposes; these are termed "essential trace elements". Among the many trace elements, iodine and zinc receive highest priority in public health interventions.