Trace elements in nails as biomarkers in clinical research

P>Background The importance of trace elements in relation to human health has been increasingly recognized. Accurate and adequate quantification of trace elements are crucial in clinical research. Design This review was to discuss the rationale of using nail trace elements as biomarkers in clinical studies. Results For most trace elements, dietary instruments cannot appropriately capture the intakes because of the minimal amounts and wide variations in the same foods grown in different area as well as the nondietary exposures. Therefore, biomarkers may be essential in studying trace elements. Although there are notable differences among trace elements in the availability of biomarkers, increasing evidence supports that nails, particularly toenail concentrations of most trace elements, are useful biomarkers of exposure in which a single sample is assumed to represent long-term exposure. Conclusions Compared with other potential biomarkers of trace elements, nail measurement has certain advantages in clinical research.