Exchangeable magnesium pool masses in healthy women: effects of magnesium supplementation.
BACKGROUND
Studying magnesium pools in the body with use of stable isotopes may be helpful for evaluating magnesium status. Data on the evaluation of magnesium pools in humans are scarce.


OBJECTIVE
We undertook this study to evaluate the effects of a magnesium supplementation program on the size of the exchangeable body pools of magnesium and on classic indexes of magnesium status in healthy women with normal magnesium status.


METHODS
Ten healthy women participated in a kinetic study with magnesium stable isotopes before and after 8 wk of magnesium supplementation. Each woman received 3 supplements containing 5.08 mmol (122 mg) elemental Mg/d (366 mg/d). Before and at the end of the supplementation period, each woman received an intravenous injection of 1.67 mmol (40 mg) (25)Mg, and the plasma magnesium disappearance curve was followed for the next 7 d. Two methods were used to analyze the exchangeable pools of magnesium: 1) formal multicompartmental modeling and 2) a simplified estimation of the total mass of the rapidly exchangeable magnesium pool (EMgP).


RESULTS
In these healthy women, exchangeable magnesium pools represented 11-12% of total body magnesium on the basis of multicompartmental analysis. The simplified estimation of EMgP overestimated the size of the exchangeable magnesium pools by approximately 45-50%. Eight weeks of magnesium supplementation did not significantly modify the size of the exchangeable magnesium pools, whereas urinary magnesium excretion was significantly higher after 8 wk of supplementation.


CONCLUSIONS
Women with no clinical evidence of magnesium deficiency may not respond to short-term supplementation with increases in the mass of the exchangeable magnesium body pool or in magnesium turnover rates.
Feillet-Coudray
Christine
C
Centre de Recherche en Nutrition Humaine d'Auvergne, Unité Maladies Métaboliques et Micronutriments, INRA, Theix, Saint Genès Champanelle, France. feillet@clermont.inra.fr
Coudray
Charles
C
Tressol
Jean-Claude
JC
Pépin
Denise
D
Mazur
Andrzej
A
Abrams
Steven A
SA
Rayssiguier
Yves
Y
D000328:Adult; D015992:Body Mass Index; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D008274:Magnesium / Q000008:administration & dosage / Q000378:metabolism*; D009752:Nutritional Status
D008274:Magnesium