2.6 Trace elements
The trace elements (also known as minor minerals or microminerals) are those that occur in quantities of less than about 5 g in the body. The more important ones are listed in Table 5, though not all of them will be considered here.
Table 5 Some trace elements needed by the human body. The functions and common food sources of the trace elements are shown.
|Element (symbol)||Functions||Main food sources|
|chromium (Cr)||found in all tissues, may be involved in blood glucose regulation||liver, cereals, beer, yeast|
|cobalt (Co)||required for formation of red blood cells||liver and other meat|
|copper (Cu)||component of many enzymes; necessary for haemoglobin formation||green vegetables, fish, liver|
|fluorine (F)||prevents tooth decay||tea, seafood|
|iodine (I)||essential constituent of thyroid hormones||milk, seafood, iodised salt|
|iron (Fe)||essential component of haemoglobin in red blood cells||meat and offal, bread and flour, potatoes and other vegetables|
|manganese (Mn)||essential component of some enzymes||cereals, pulses, nuts|
|molybdenum (Mo)||essential component of some enzymes||kidney, cereals, vegetables, fruit|
|selenium (Se)||essential component of some enzymes; associated with Vitamin E activity||cereals, meat, fish, eggs, Brazil nuts|
|Zinc (Zn)||essential component of many enzymes and other proteins; required for steroid and thyroid hormone activity||meat and meat products, milk and cheese, bread flour and cereal products, peanuts|