Calcium metabolism in a fatal case of sodium fluoride poisoning.

A patient was admitted to a district general hospital within an hour of ingesting a fatal dose of sodium fluoride. The results of laboratory investigations, together with some in vitro findings, support the hypothesis that the hypocalcaemia of fluoride poisoning is the result of fluorapatite formation and not calcium fluoride precipitation, and that its persistence reflects the severity of the calcium deficit and not an inhibitoin of normal homeostatic mechanisms. It is suggested that the role of renal clearance of fluoride may be more important than had been realised hitherto.