Erythrocyte magnesium concentration as an index of magnesium status: a perspective from a magnesium supplementation study

We investigated the utility of erythrocyte magnesium concentrations as an i ndex of magnesium status. Calculated from the analytical and biological var iation, the critical difference, i.e. the difference between results from s erial specimens before they can be said to be statistically different, was 22.4% (P < 0.05). Magnesium supplementation of 250 mg/day for 3 weeks in 20 women with an erythrocyte magnesium concentration less than the 15th perce ntile of a population sample (n = 219), resulted in an increase in erythroc yte magnesium concentration of only 1.6%. We therefore conclude that sequen tial erythrocyte magnesium measurements are not useful for the monitoring o f individual changes in magnesium intake and status, (C) 2000 Elsevier Scie nce B.V. All rights reserved.