This rat study fed cerium oxide or lanthanum carbonate in the diet of rats with surgically reduced kidney function to compare them as phosphate binders. Cerium oxide lowered serum phosphate without raising liver enzymes over four weeks, whereas the lanthanum carbonate groups showed higher alanine transaminase. The study was funded by a pharmaceutical company that employs three of the authors, and tissue cerium was not measured.
Key numbers
- Diets contained 1.31% cerium oxide or 0.5% lanthanum from lanthanum carbonate; the authors judged these to have comparable phosphate-binding capacity (Table 2 and p. 8).
- Group sizes were 5 to 6 rats; feeding lasted up to four weeks (Methods, p. 3).
- Alanine transaminase was higher in lanthanum carbonate-fed nephrectomized rats than in other groups, while cerium oxide groups did not show raised alanine or aspartate transaminase (Fig. 9, p. 10).
Methods (brief)
Cerium oxide was first tested for phosphate adsorption in vitro at pH 2.5 and 7.0. Male Wistar rats underwent sham or 5/6 nephrectomy and received casein or soy protein diets with no binder, lanthanum carbonate, or cerium oxide; food, water, feces and urine were recorded and serum and urine biomarkers measured.
Evidence fitness
Supports a statement that dietary cerium oxide at about 1.3% of the diet was tolerated over four weeks in this rat model with no rise in liver enzymes, and that lanthanum carbonate raised alanine transaminase. It does not measure cerium absorption or tissue levels and cannot support human safety conclusions.
Limitations
Short duration; small groups; cerium distribution in the body not studied (the authors call for accumulation studies); funded by applausePharma Co., Ltd., with three authors employed by an affiliated company.
Related evidence
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