Ionized magnesium in erythrocytes--the best magnesium parameter to observe hypo- or hypermagnesemia

Clin Chim Acta. 2004 Nov;349(1-2):67-73. doi: 10.1016/j.cccn.2004.06.006.


Background: Almost 99% of the body magnesium is inside cells. The concentration of intracellular ionized magnesium (iMg) is physiologically relevant. iMg in erythrocytes is a new parameter that can help to establish reliable information on the functional magnesium status.

Methods: iMg concentration in erythrocytes and serum was measured by ion-selective electrode, in clinical analyzer Microlyte (KONE). Total magnesium (tMg) concentration was measured by atomic absorption spectrometry (AAS). Albumin and total protein concentration were measured colorimetrically.

Results: In critically ill postoperative patients, the mean of albumin, protein and hematocrit concentration was significantly lower compared to healthy individuals. Hypomagnesemia was found in 15.9% patients as tMgs, at 22.2% as iMgs and 36.5% as iMge. Significant correlations are between iMgs and tMgs or iMge and iMgs/tMgs. In dialyzed patients, the mean of hematocrit was significantly lower, iMge was significantly higher compared with healthy individuals. Significant negative correlations are between iMgs and tMge or iMge/tMge and tMge.

Conclusions: iMge is the best magnesium parameter to observe hypo- or hypermagnesemia for both groups of patients. The function of magnesium is mainly intracellular and intracellular magnesium concentrations can be the method to evaluate the magnesium status.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Critical Illness
  • Erythrocytes / chemistry*
  • Female
  • Humans
  • Magnesium / blood*
  • Magnesium Deficiency / blood*
  • Male
  • Middle Aged
  • Renal Dialysis


  • Magnesium