Serum magnesium concentration: time for a standardised and evidence-based reference range

Area of Science:

• Clinical Chemistry
• Biochemistry
• Preventive Medicine

Background:

• Total serum magnesium concentration is infrequently measured in clinical settings.
• Current serum magnesium reference ranges lack standardization and an evidence-based foundation.
• Variability exists among laboratories regarding the lower limit of serum magnesium.

Purpose of the Study:

• To propose an evidence-based reference range for serum magnesium.
• To highlight the preventive potential of optimal magnesium levels.
• To advocate for standardization of serum magnesium testing.

Main Methods:

• Literature search conducted in the PubMed database.
• Keywords used: "serum magnesium", "reference interval", "reference range", "hypomagnesemia".
• Citations from relevant studies were also reviewed.

Main Results:

• Existing lower limits for serum magnesium vary significantly between laboratories.
• Most current lower limits are below the 0.85 mmol/L (2.07 mg/dL) threshold recommended by expert groups.
• Lower serum magnesium levels are associated with increased risks of type 2 diabetes and cardiovascular diseases.

Conclusions:

• The lower limit of serum magnesium should be standardized at 0.85 mmol/L to mitigate health risks.
• Laboratory reports should indicate the increased disease risk associated with levels below 0.85 mmol/L.
• Serum magnesium determination should be prioritized in routine diagnostics, similar to other electrolytes.