[Urinary excretion of calcium, magnesium, uric acid and oxalic acid in normal children].

A group of normal children with a free diet was studied. Their first morning urine (n = 176) and their 24-hour-urine (n = 64) was collected, valuing the calciuria, magnesiuria, uricosuria and oxaluria, establishing their relationship with a dietetic survey. Ca/Cr rate value was 0.13 +/- 0.7 mg/mg in the morning urine, and 0.12 +/- 0.06 mg/mg in the 24-hour-urine. Calciuria (mg/kg/day) was 2.46 +/- 1.45, higher to that noticed by other authors. Prevalence of hypercalciuria was 7.8%. We haven't noticed any correlation between the calciuria (mg/kg/day) and the consumption of proteins and carbohydrates. A positive correlation was found between Ca/Cr and Na/Cr rate, together with high natriuria (3.87 +/- 1.35 mEq/kg/day); these findings could justify the elevated calciuria in the children studied. Mean values of magnesium and uric acid were 0.04 +/- 0.02 and 0.30 +/- 0.08 mg/100 ml FG, respectively and the oxaluria was 34.51 +/- 16.35 mg/day/1.73 m2.