ABSTRACT
A very significant number of elements is present in the diet in small quantities. There is an increasing interest in these elements because several of them are recognized as being so critical to one or another body function that when there is not an adequate amount of the element, a deficiency syndrome evolves. Several of the trace elements are quite unique in that they appear to be required in very trace quantities, but begin to exhibit toxic effects at higher levels. Iron was recognized as an important trace element more than 100 years ago at a time when it was found to be a key element in hemoglobin. The rate of movement of most trace elements into and out of the body is quite slow. Urine study provides an important approach for the study of certain of the trace elements with respect to their relation to various disorders.
