[The provoked hypercalciuria test. Significance and limitations]

The calcium tolerance test is of diagnostic importance only in osteomalacia, which it helps to identify before bone biopsy when the static phosphocalcic parameters are not a deciding factor. However, the test does not make it possible to distinguish an osteoporosis from a cortisone osteopathy or an idiopathic hypercalciuria. In the first two diseases, the rates of urinary calcium elimination are comparable to that of normal individuals. It seems that the rate of urinary elimination of I.V. administered calcium is, approximately, all the more elevated as the level of iPTH is low; and, when the level of iPTH is low, the osteoid tissue seems less calcified than normally.