The metabolic roles of trace elements in aging have become of concern to nutritionists and were the subject of a symposium. Data for metabolic balances for different age groups were available for zinc, copper, and selenium but not for chromium possibly because of analytical problems. The availability and concentration of certain trace elements in the diet and/or in a specific tissue might alter the production of the free radicals. The most complete report of plasma zinc concentration for different age groups from premature infants to adults was reported by Berfenstam in 1952. However, total hair zinc concentration may not accurately indicate current zinc status. There is general agreement that hair chromium changes markedly with age. The normal mean plasma or serum chromium concentrations reported have varied between 0.73 to 150 ng/ml. There apparently is agreement that the concentrations of selenium in plasma, serum, RBC, and whole blood are lower in old than in young persons, especially after 60 years.