Reference ranges for select elements and metals in healthy biomatrices

Area of Science:

• Environmental Health
• Analytical Chemistry
• Clinical Biochemistry

Background:

• Establishing reliable reference values (RVs) for elements and metals in biological samples is critical for accurate health assessments.
• Existing RVs vary significantly due to geographical, demographic, and analytical differences.
• A comprehensive global review of current RVs is needed to identify discrepancies and guide future research.

Purpose of the Study:

• To consolidate and compare existing reference values for elements and metals in biological samples from healthy populations worldwide.
• To identify variations in reported reference values across different countries and methodologies.
• To underscore the need for localized and standardized reference values.

Main Methods:

• A systematic literature review was conducted using Web of Science, PubMed, and Scopus.
• Included studies were published in English between January 2012 and February 2022.
• Eligible studies involved at least 120 participants, evaluated at least 3 elements/metals, and analyzed biological samples (whole blood, serum, plasma, umbilical cord, hair).

Main Results:

• Twenty-nine studies from 15 countries, encompassing 26,676 healthy individuals aged 0-80 years, were included.
• Data on 36 trace/micro/meso/macro/toxic metals and elements were extracted.
• Significant variations in reference ranges, means, medians, and confidence intervals were observed, attributed to geographical factors, demographics, and analytical methods.

Conclusions:

• Localized reference values are essential for accurate clinical evaluations and bio-monitoring.
• Standardized analytical methodologies are required to ensure comparability and reliability of results.
• Further extensive studies across diverse populations are necessary to develop comprehensive reference values for elements and metals.