Bioavailability of oral magnesium supplementation in female students evaluated from elimination of magnesium in 24-hour urine

Magnes Trace Elem. 1990;9(5):272-8.


The bioavailability of Mg from different preparations after oral intake has been evaluated by measuring the Mg elimination in 24-hour urine during placebo and treatment periods in 18 normal female students receiving 15-20.6 mmol/day. The urine elimination was increased 0.9-1.3 mmol/24 h by (a) tablets containing Mg citrate/Mg lactate 5 mmol three times a day; (b) tablets containing Mg citrate/Mg lactate and Mg hydroxide, 5 mmol three times a day; (c) tablets containing Mg hydroxide (Emgesan 10.3 mmol) twice a day; (d) solutions with Mg chloride (0.5 mmol/ml) 10 ml three times a day. There was no statistical difference in urine elimination after intake of the different preparations. The differences in Mg elimination/24 h discriminated between control and treatment groups just as well as or better than differences calculated on the basis of Mg/creatinine ratios.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial

MeSH terms

  • Administration, Oral
  • Adult
  • Biological Availability
  • Creatinine / urine
  • Diet
  • Female
  • Humans
  • Magnesium / administration & dosage
  • Magnesium / pharmacokinetics*
  • Magnesium / urine
  • Metabolic Clearance Rate / drug effects
  • Random Allocation


  • Creatinine
  • Magnesium