Urinary excretion of magnesium in healthy male infants

Many reference values of biochemical tests depend at least on age, sex, nutrition, and analytical method. They are not widely available, particularly not in infants. We obtained serum and urine samples from 28 healthy term male infants aged 2 to 12 months (mean = 6.45 months). We studied eight parameters of renal excretion of magnesium and obtained urine magnesium data for establishing reference values (percentils 5% and 95%): urine concentration 0.51-7.59 mmol/l, 24 hours urine output 0.1-1.2 mmol, urine output weight related 4.3-163.9 μmol/kg, urine output related to 1 mol of creatinine 0.13-1.76 mol/l mol, clearance 0.18-4.17 ml/min/1.73 m², fractional excretion 0.59-9.38%, U-Ca/U-Mg ratio 0.26-2.92, and U/S-Mg ratio 0.11-5.76. No significant correlation with age for this group of infants was demonstrated for the studied parameters. Evidence of lognormal data distribution proved by Kolgomorov-Smirnov's test was demonstrated only for the U-Ca/U-Mg ratio and evidence of normal data distribution proved by Kolgomorov-Smirnov's test was demonstrated for all other studied parameters. The majority of obtained results correlates very well with data published previously. However several results presented in this article are unique and therefore no comparison is available.