Trace Elements in Human Nutrition.

A number of trace elements are required by man, but clear-cut evidence of deficiency has been observed for only iodine and iron. Despite the fact no evidence exists that human diets may be deficient in trace minerals other than iron and iodine, there is an increasing tendency to add more and more minerals to vitamin-mineral preparations. Since potassium iodide is a mandatory constituent of table salt in Canada, iron is apparently the only trace element which may not be consumed in adequate amounts under Canadian conditions, and whose addition to dietary supplements for sale to the general public can be justified. It is suggested that trace elements other than iron should not be advertised to the general public, but should be administered only on the advice of a physician, who is in a position to judge the merit of available products in each specific situation.