Biomarkers for assessing magnesium status.
Level 5 - mechanism / opinion, no new human data
Narrative review/book chapter synthesizing biomarker mechanisms without systematic search or meta-analysis
PubMed 42336500 · doi:10.1016/bs.acc.2026.03.006
What was done
This chapter reviewed current and emerging methods for assessing magnesium (Mg) status based on physiological mechanisms of absorption, renal regulation, and bone storage. It evaluated extracellular measures (serum/plasma, free ionized, urine), intracellular measurements (red blood cells, leukocytes, platelets), non-invasive matrices (hair, nails), functional testing (Mg loading tests, balance studies), and emerging methods including the Magnesium Depletion Score (MDS) and genetic biomarkers (TRPM6, TRPM7, CNNM family, MAGT1).
What was found
No quantitative diagnostic metrics (such as sensitivity, specificity, or reference ranges) were reported in the abstract. The review noted that less than 1-2% of total body magnesium is found in blood and extracellular fluid, rendering standard serum magnesium insensitive for detecting subclinical deficiency. The authors noted that no single biomarker reliably captures whole-body Mg status and that multi-marker or functional assessments may offer superior diagnostic accuracy.
Why it matters
Because serum magnesium is homeostatically buffered, relying on routine blood tests alone can overlook tissue magnesium depletion in clinical and epidemiological settings. Integrating functional tests and clinical scores may improve the detection of subclinical deficiency associated with non-communicable diseases.
Limits
This is a narrative review that reports no primary empirical data or quantitative diagnostic performance metrics. The abstract does not specify literature search methods, study screening criteria, or sample sizes.
Cited by
- supports Serum magnesium tests cannot accurately detect cellular or tissue magnesium depletion unless the deficiency is severe.