[Nutritional biological markers of deficiencies of zinc, copper and selenium].

Direct and indirect indices used for the assessment of copper, zinc or selenium status in humans are reviewed. Variations, advantages and disadvantages are discussed. Despite the numerous indices, none of them provide a satisfactory assessment of the nutritional status for these trace elements. The best indices are probably serum zinc and alkaline phosphatase for the assessment of zinc status, serum selenium for the assessment of selenium status and possibly erythrocyte Cu-Zn superoxide dismutase for the assessment of copper status.