Oral aluminum bioavailability from two representative foods is considerably less than from water

Oral bioavailability of aluminum (Al) from water has been quite well characterized; but not from food. For many people ~ 95% of daily Al intake is from food. The objective of this study was to determine the oral bioavailability of Al from two representative foods containing an FDA‐approved Al‐containing food additive, sodium aluminum phosphate (SALP); biscuit containing the leavening agent acidic SALP and cheese containing the emulsifier basic SALP. 26 Al‐containing SALPs were prepared as described ( Nucl. Instr. Meth. Physics Res. B. 229:471‐478, 2005). Male Fisher rats were trained to eat 1 gm of biscuit or cheese under conditions in which they had no stomach contents. They then consumed biscuit containing 1 or 2% acidic 26 Al‐SALP or cheese containing 1.5 or 3% basic 26 Al‐SALP (~ 1 to 2 nCi 26 Al/gm food) while receiving an i.v. infusion of 27 Al. Blood was withdrawn before and repeatedly up to 60 hours for quantification of 26 Al by accelerator mass spectrometry and 27 Al by atomic absorption, to enable determination of the area under the Al concentration x time curve (AUC) of each. Oral 26 Al bioavailability was determined as the sum of the trapezoidal (AUC po /AUC iv ) × (dose iv /dose po ). Oral Al bioavailability from biscuit was 0.013%, and not acidic 26 Al‐SALP‐concentration dependent. Oral Al bioavailability from cheese with 1.5 or 3% basic 26 Al‐SALP was 0.015 and 0.032%, respectively, which were significantly different. Oral Al bioavailability from these foods is less than from water (~ 0.3%; Toxicology , 161:93‐101, 2001 and Zhou and Yokel this meeting). Supported by NIH R01 ES11305.