Abstract: Objective: To assess the enhancing effect of a commercially available calcium supplement on bone mineral density in rats and to compare the application of dual energy X-ray absorptiometry (DEXA) and Archimedes, principle bone mineral density. Methods: According to Protocol 1 from   Method for Testing the Function of Increasing Bone Density,, 2003 Technical Standards for Testing and Assessing of Health Food, 45 weaned SD rats were divided at random into calcium carbonate control group, low calcium control group, and high-dose, medium-dose and low-dose calcium supplement groups (administered at doses of 1.00, 0.33 g/kg and 0.17 g/kg, respectively). Results: The high-dose group showed a significant increase in apparent calcium absorption rate, body weight gain, and bone mineral density and calcium content when compared with the low-dose group (P ＜ 0.05). All indexes investigated except bone mineral density indicated no significant difference between the high-dose and calcium carbonate control groups. There was a good correlation between the results of bone mineral density determination by the DEXA method and Archimedes, principle. Conclusions: The calcium supplement has an enhancing effect on bone mineral density in rats. Moreover, the DEXA method and Archimedes, principle are both applicable for the determination of bone mineral density.

Key words: rats, bone mineral density (BMD), dual energy X-ray absorptiometry (DEXA), Archimedes, principle