The body also requires small amounts of a range of minerals and trace elements. The most important are potassium, sodium, chloride, magnesium, iron, zinc, selenium, chromium and iodine. Although the various mineral substances only make up about 4% of body weight, they are essential for life. For example, iron is required in order to allow oxygen to be transported around the body, whereas zinc is very important for wound healing and in relation to fertility.
Minerals are not produced by the body and must be supplied through food and drink. The recommended daily intake of minerals is from 100 mg to about 1 g. Trace elements, such as manganese, are also required by the body in very small amounts. Daily doses of trace elements vary from a few tens of mg down to microgram amounts.