Reference ranges for select elements and metals in healthy biomatrices

Abstract

Introduction/Objective: This review aimed to consolidate and compare reference values (RVs) for various elements and metals in biological samples from healthy populations worldwide. Methods: A Web of Science/PubMed/Scopus review was conducted. Original articles in the English language, from January 2012 to February 2022, with at least 120 participants and 3 evaluated elements, and biological samples of whole blood, serum, plasma, umbilical cord, and hair included in this review. Results: Ninety-nine studies were screened and assessed, and eventually, 29 eligible studies from 15 countries and a total recruitment of 26,676 healthy subjects, ages ranging from zero to 80 years were included in this review. The results of evaluating 36 trace/micro/meso/macro/ toxic metals and elements in biological fluids and hair were extracted from eligible studies. Several indicators include reference range (lower, upper), arithmetic and geometric mean, median, percentile (lower, upper), and confidence interval (CI) 95 of evaluated elements were reported. Due to geographical conditions, different demographic factors, and different analytical methodologies, the results of the analysis were various in different countries. Conclusions: This review points out the necessity for localized RVs and standardized methodologies for accurate clinical evaluations and bio-monitoring. The findings call for extensive studies across diverse populations to develop comprehensive RVs for elements and metals, ensuring effective health assessments and environmental exposure controls.