Unit 11
Trace Minerals

Although present in only minute amounts in the body (less than 0.01 per cent of body weight), trace minerals are essential for many vital functions. The “essentiality” of such small quantities is often difficult to determine; however, the development in recent years of highly sensitive instruments has enabled investigators to analyze food and tissue samples for extremely low concentrations, and to gain a clearer understanding of the role of trace minerals.

The trace minerals known to be essential for humans are iron, zinc, iodine, selenium, copper, manganese, fluorine, chromium, molybdenum, and cobalt. Others that may also be essential are arsenic, silicon, nickel, boron, tin, and vanadium. The list grows as more is learned.

Instead of providing detailed information on each trace mineral, we look at their general characteristics, such as functions, absorption, transport, and excretion, and dietary sources. We cover iron and zinc in greater detail. Finally, we discuss the need for vitamin and mineral supplements.

This unit consists of the three sections listed below.

• Section 11.1  General Characteristics of Trace Minerals
• Section 11.2  Iron and Zinc
• Section 11.3  The Need for Vitamin and Mineral Supplements