<prompt> Which of the following is not a trace element?ZinccopperSeleniumcalcium  <response>: Definition of trace elements : Elements present at concentrations of mgdl in body fluids and mgkg in tissues are referrd to as trace elements . Calcium reference range in blood : 8.6 - 10.3 mgdl. Teitz textbook of clinical biochemistry, chapter Vitamins and trace elements. 