Mineral metabolism of rats fed various levels of aluminum hydroxide

Abstract

The effect of ingesting nutritionally complete diets with added aluminum hydroxide (257 μg Al/g diet in study A and 1075 μg Al/g diet in study B) was assessed in two 67-d studies. Rats fed either 257 or 1075 μg Al/g diet accumulated significantly greater amounts of aluminum in their tibias, kidneys, and livers than control animals. However, the rats fed 1075 μg Al/g diet did not accumulate more aluminum in these tissues than rats fed 257 μg Al/g diet. After consuming the diets for 30–39 d, the rats fed 257 μg Al/g diet absorbed calcium, magnesium, and copper significantly less efficiently, and the rats fed 1075 μg Al/g diet absorbed phosphorus and calcium significantly less efficiently than control animals. After the rats had consumed the diets for 62–65 d, the additional aluminum hydroxide no longer affected the apparent absorption or tissue concentrations of phosphorus, calcium, magnesium, zinc, or iron. Rats fed 1075 μg Al/g diet had significantly higher concentrations of copper in their tibias, but significantly less total calcium, magnesium, and zinc in their tibias and livers and less total iron in their tibias than control animals. The reduced breaking strength of bones from the animals fed 1075 μg Al/g diet may reflect their slightly smaller size.