All are trace elements except -
Trace elements are elements required by the body in quantities of less than a few milligrams per day.eg.iron,iodine,flourine,zinc,copper cobalt,chromium,manganese,molybdenum,selenium,nickel,tin,silicon and vanadium.(Ref.PARK'S textbbok of sociala and preventive medicine 21st edition page no.573)
Iron
Fluoride
Potassium
Zinc
Nutrition and health