Mineral elements account for approximately 4% of body weight. Some, such as calcium and phosphorus, are present in the body in relatively large amounts whereas others occur in very small quantities and are known as trace elements.
Trace elements are found only in very small quantities, i.e in a matter of milligrams. Examples are iodine (20-50 mg), copper (100 mg) manganese (2000 mg) and zinc (1-2 mg).
The definition of ‘trace elements’ is arbitrary and not fixed: a trace element is one which is essential of normal cell function, but is required only in tiny amounts. Many of the trace elements are concerned in enzymes system of the body.
Trace elements (Fe, I, F, Zn, Se, Cu, Mn, Cr, Mo, Co, Ni) are essential in concentrations of less than 50 mg/day; their biochemical actions have been elucidated. Some of the elements are never in short supply because the food eaten, whatever the diet contains ample amounts.
Trace elements of minerals