What does the Magnesium test measure?

Why is Magnesium measured?

Serum magnesium is the standard, widely available measure of magnesium status and is used to detect and monitor hypomagnesaemia and hypermagnesaemia. Because most magnesium is intracellular, a normal serum value does not exclude tissue depletion, and clinically significant deficiency can exist with borderline-normal serum levels. It is most useful in patients with relevant symptoms, electrolyte disturbances (especially refractory hypokalaemia or hypocalcaemia), or conditions and drugs that deplete magnesium.

Reference ranges

Standard reference

1.7–2.4 mg/dL (0.70–0.99 mmol/L) # REVIEWER FLAG: Reference interval is assay-dependent — reviewer to confirm against Access Medical Laboratories' assay-specific range.

Functional medicine optimal

Many practitioners target the upper half of the reference range (≥2.0 mg/dL) as functionally optimal # REVIEWER FLAG: Functional 'optimal' magnesium target is not standardised — reviewer to confirm against IFM or equivalent source.

Units

mmol/L, mg/dL

Reference ranges vary by laboratory and assay platform. Interpret in context of the issuing laboratory's stated range.