Aspects of renal bone disease.

In advanced chronic renal failure hypocalcaemia can be due to a combination of factors. These include decreased delivery of calcium into the plasma and increased renal tubular leakage of calcium. The secondary hyperparathyroidism that follows the hypocalcaemia leads to osteosclerosis, probably by movement of cortical mineral into trabecular bone. In the dialysis population, an atypical and readily identifiable form of osteomalacia sometimes occurs and is probably secondary to a water-borne toxin.