ORAL MAGNESIUM LOAD TEST FOR THE ASSESSMENT OF INTESTINAL MAGNESIUM ABSORPTION - APPLICATION IN CONTROL SUBJECTS, ABSORPTIVE HYPERCALCIURIA, PRIMARY HYPERPARATHYROIDISM, AND HYPOPARATHYROIDISM

  • 1 January 1982
    • journal article
    • research article
    • Vol. 8  (1) , 44-51
Abstract
The intestinal absorption of Mg was estimated from the increment in urinary Mg following oral administration of 25 mmol of Mg. Fasting urinary Mg did not differ between the control group and patient groups (absorptive hypercalciuria, primary hyperparathyroidism and hypoparathyroidism). As compared to the value in the control group, the increment in urinary Mg above the fasting value was not significantly different in absorptive hypercalciuria. It was significantly increased in primary hyperparathyroidism and significantly reduced in hypoparathyroidism. In control subjects, the increment in urinary Mg was much higher during a low than during a high Ca diet. 1,25-(OH)2-Vitamin D stimulates Mg absorption, since Mg absorption was elevated in situations associated with stimulated 1,25-(OH)2-vitamin D synthesis (primary hyperparathyroidism and low Ca diet) and reduced in a condition characterized by low 1,25-(OH)2-vitamin D production (hypoparathyroidism). 1,25-(OH)2-Vitamin D may not be pathogenetically important in absorptive hypercalciuria, since Mg absorption was normal.