Evidence for aluminum absorption from the gastrointestinal tract and bone deposition by aluminum carbonate ingestion with normal renal function

The question of whether aluminum is toxic in patients ingesting large oral loads, either for phosphate binding in renal dialysis or as an antacid for peptic ulcer, has been raised. The permeability of the gut barrier for aluminum has not been established because of the lack of precise analytical techniques. Urine aluminum was measured in this study before and during oral aluminum carbonate loading in six subjects with normal renal function, one of which had peptic ulcer disease and a 25-year history of high oral aluminum ingestion. The analytical procedure involved destructive neutron activation analysis. Aluminum was present in the urine in all instances before loading and rose in every case from 4-fold to 10-fold. Bone aluminum was measured in six autopsy specimens, three dialysis patients, three nondialysis patients, and in an iliac crest biopsy from the peptic ulcer patient who had osteoporosis. The bone biopsy aluminum level in the ulcer patient was intermediate between those of 'normal subjects' and patients on dialysis. These results show that the gut barrier is permeable to heavy aluminum load and suggest that bone aluminum deposition occurs in humans with normal renal function.