Minerals are simple-structured substances that play major roles in many metabolic functions. Many minerals are components of enzymes, which are catalysts of chemical reactions in the body. Additionally, minerals regulate and control the normal function of human and animal tissues, muscles, and organs. For example, sodium and potassium play a vital role in maintaining proper fluid balance. Calcium acts as a major structural component of bones and teeth. Iron carries oxygen throughout the body in blood.

Minerals are divided among two classes, major minerals and trace minerals. Animals and humans need major minerals, including sodium, potassium, calcium, magnesium, and phosphorus in large amounts. Trace minerals, also called trace elements, are needed in small amounts, although that should not be taken as an indication of the importance of trace minerals for the proper functioning of the body. Some of the most essential trace minerals include iron, zinc, copper, selenium, chromium, and iodine.

This SparkNote reviews the important major and trace minerals, their unique important functions, how they are absorbed and excreted by animals and humans, in what foods they can be found, and their supplemental uses. The guide begins with a section on water and fluid balance, a vital metabolic process which incorporates many minerals. The further readings can be consulted for more detailed explanation of metabolic functions and discussion on other nonessential minerals such as metals.