Effect of chronic magnesium supplementation on magnesium distribution in healthy volunteers evaluated by 31P-NMRS and ion selective electrodes.
OBJECTIVE
The role of magnesium (Mg) intake in the prevention and treatment of diseases is greatly debated. Mg biodistribution after chronic Mg supplementation was investigated, using state-of-the-art technology to detect changes in free ionized Mg, both at extra- and intracellular levels.


METHODS
Thirty young healthy male volunteers participated in a randomised, placebo (P)-controlled, double-blind trial. The treated group (MgS) took 12 mmol magnesium lactate daily for 1 month. Subjects underwent in vivo 31P-NMR spectroscopy and complete clinical and biological examinations, on the first and last day of the trial. Total Mg was measured in plasma, red blood cells and 24 h urine ([Mg]U ). Plasma ionized Mg was measured by ion-selective electrodes. Intracellular free Mg concentrations of skeletal muscle and brain tissues were determined noninvasively by in vivo 31P-NMR at 3T. NMR data were automatically processed with the dedicated software MAGAN.


RESULTS
Only [Mg]U changed significantly after treatment (in mmol/24 h, for P, from 4.2+/-1.4 before to 4.1+/-1.3 after and, for MgS, from 3.9+/-1.1 before to 5. 1+/-1.1 after, t=2.15, P=0.04). The two groups did not differ, either before or after the trial, in any other parameter, whether clinical, biological or in relation with the Mg status.


CONCLUSIONS
Chronic oral administration of Mg tablets to young healthy male volunteers at usual pharmaceutical doses does not alter Mg biodistribution. This study shows that an adequate and very complete noninvasive methodology is now available and compatible with the organization of clinical protocols which aim at a thorough evaluation of Mg biodistribution.
Wary
C
C
Institut de Myologie, Groupe Hospitalier Pitié-Salpêtrière, Paris, France.
Brillault-Salvat
C
C
Bloch
G
G
Leroy-Willig
A
A
Roumenov
D
D
Grognet
J M
JM
Leclerc
J H
JH
Carlier
P G
PG
D000328:Adult; D000465:Algorithms; D001774:Blood Chemical Analysis; D001794:Blood Pressure / Q000187:drug effects; D001921:Brain / Q000378:metabolism; D004032:Diet; D004311:Double-Blind Method; D004912:Erythrocytes / Q000378:metabolism; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008274:Magnesium / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism; D015203:Reproducibility of Results; D013607:Tablets; D014018:Tissue Distribution
D013607:Tablets; D008274:Magnesium