[Metabolism and utilization of calcium derived from hydrolysed oyster shell in rats]

Experimental rats modeled on calcium deficiency were fed with calcium derived from hydrolysed oyster shell, calcium carbonate and calcium chloride respectively, equivalent to 45 mg a day, for four weeks to study their bioavailability. Calcium contents in the blood, urine, feces and bone of rats were determined with atomic absorption spectrometry and EDTA complex titration, and their bone density was measured with densitometry. Results showed proportions of calcium absorption and retention were 67.3% +/- 16.7% and 64.6% +/- 17.5%, respectively, in rats fed with calcium from hydrolysed oyster, and their femur calcium content and bone density (BMC/BW) 131.2 +/- 1.48 mg/g and 0.318 +/- 0.034 g/cm2, respectively, significantly higher than those in the rats fed with calcium carbonate. There were no significant difference in blood calcium contents, weight gains and feed intake between those three groups of rats. It suggests that calcium derived from hydrolysed oyster shell may be absorbed and utilized more easily than calcium carbonate.