Hypercalcaemic osteomalacia due to aluminium toxicity

In 16 patients with chronic renal failure and osteomalacia resistant to vitamin-D therapy, aluminium was demonstrated in bone biopsy specimens at the interface between thickened osteoid and calcified bone by means of both X-ray microanalysis and a specific histochemical stain. 14 patients also had hypercalcemia. It is suggested that this is due to the blocking by aluminium of additional calcium uptake into bone coupled with the availability of additional calcium from dialysis fluid and vitamin-D therapy. This study provides more aetiological evidence linking aluminium and the development of osteomalacia in chronic renal failure. Further, if hypercalcaemia develops in such patients it is important that aluminium toxicity be excluded as the cause to prevent unnecessary parathyroidectomy.