Benefit vs. risk of oral aluminum forms: antacid and phosphate binding vs. absorption

Oral consumption of aluminum (Al) compounds to neutralize stomach acid and bind phosphate can result in Al absorption and potential Al accumulation and toxicity. Selecting an effective antacid/phosphate binder would optimize the benefit/risk of therapy. It has been suggested that Al solubilization would predict oral Al bioavailability, and therefore risk. The acid neutralizing and phosphate binding capacity of eight representative Al forms was determined. The results were compared to the oral bioavailability, solubility and octanol/water partitioning coefficient of each compound. The results fail to confirm Al solubilization as an indicator of Al absorption, and presumably, Al toxicity. Acid neutralizing and phosphate binding capacities did not correlate with bioavailability, solubility or the partitioning coefficient. Determination of acid neutralization and phosphate binding in vitro and Al absorption and/or toxicity in vivo may be more predictive measures to establish the benefit/risk ratio of Al-containing products.