The Calcium and Magnesium Content of Normal Urine

Considerable difference of opinion exists at present concerning the relative amounts of calcium and magnesium excreted in normal urine. Hammarstenl states that of a daily urinary excretion of somewhat more than 1 gm., two-thirds is magnesium and one-third calcium. Bertram in a 3 day period found 0.268 gm. of MgO and 0.167 gm. of CaO; RenvalJ3 and Long and Gephart,4 on the contrary, report figures showing an excess of calcium over magnesium. Labbe and Gallippe5 found the ratio of MgO to CaO in urine to be 0.56 in normal subjects, while in tuberculosis cases it was 0.46. In this paper we are reporting on the urinary magnesium and calcium excretion of three normal men over periods of 5 days and the daily excretion of twenty-two apparently normal university students. The urines were carefully collected in periods of 24 hours, care being taken to collect the entire amounts voided. The calcium and magnesium were determined by McCrudden’s6 method. The diet was not in any way restricted, being in each case that of home or boarding-house.