Trace elements are minerals needed in small amounts by plants, animals, and human beings. Such major elements as calcium, carbon, chlorine, hydrogen, magnesium, nitrogen, oxygen, phosphorus, potassium, sodium, and sulfur are part of the makeup of all living things. The trace elements are also necessary to life. Scientists know the uses of only a few of the trace elements. But scientists do know that they are necessary for the work of such vital bodily compounds as enzymes and hormones (see Enzyme ; Hormone ).
The trace elements include chromium, copper, fluorine, iodine, iron, manganese, molybdenum, selenium, and zinc. The body needs copper so it can use iron to build hemoglobin, an important part of red blood cells. Iodine is needed to form the hormone thyroxine. A lack of iodine in the diet results in goiter, a disease characterized by excessive growth of the thyroid gland. Manganese and zinc are required for the normal action of certain enzymes. Without these two minerals, certain reactions in the body cells would stop. Human beings and all animals need the same trace elements, but plants have different requirements. For example, plants do not need iodine or fluorine. Human beings get the required trace elements from their food in a balanced diet.
