Bioavailability of Aluminum

Inhalation is mostly an occupational exposure route (De Voto and Yokel 1994). Approximately 3% is absorbed by this route. Welders exposed to a maximum of lOmg/m had raised plasma and urinary Al levels, although they showed no overt signs of toxicity (De Voto and Yokel 1994). Outside the work place, exposure via inhalation is minimal. 

---

Calcium citrate should not be administered with aluminum-containing compounds. Concomitant administration may increase systemic bioavailability of aluminum and predispose to toxicity... 

Oral bioavailability of aluminum compounds appears to generally parallel water solubility, but current knowledge does not allow a straight extrapolation from solubility in water to bioavailability. Studies of aluminum speciation in the stomach and intestines, including mathematical modeling, would be useful because they could enable such an extrapolation by helping to resolve the critical role of speciation in making aluminum available to uptake mechanisms. 

Conway EL, O Callaghan C, Drummer OH, et al. 1994. A single-dose comparison of the bioavailability of aluminum from two formulations of sucralphate in normal volunteers. Biopharm Drug Dispos 15 253-... 

Gardner MJ, Gunn AM. 1995. Speciation and bioavailability of aluminum in drinking water. Chem Speciat Bioavail 7 9-16. 

Gjessing ET, Riise G, Petersen RC, et al. 1989. Bioavailability of aluminum in the presence of humic substances at low and moderate ph. Sci Total Environ 81/82 683-690. 

It should be noted that the human body does possess natural barrier systems to prevent aluminum intake. There are various physiological ligands, such as transferrin, citrate, and silicilic acid, which are efficient buffers in preventing the intake of aluminum under natural conditions [28]. Yet the formation of TFA requires only trace amounts of aluminum, and the bioavailability of aluminum to living organisms is increasing. Fluorine, of course, is readily available in drinking water. 

Farrar G, Morton AP Blair JA. (1988). The intestinal spectiation of gallium Possible models to describe the bioavailability of aluminum. In Trace Element Analytical Chemistry in Medicine and Biology, Bratter P Schramel P, pp. 343-347. Walter de Gruyter, Berlin. 

---