[Influence of calcium content among different calcium agents on absorbing and bone density of rats]

To identify the influence of different calcium contents among different calcium agents on absorbing and born density of rats, wistar rats are fed with diet containing different contents of calcium of different calcium agents. 3-day calcium metabolization experiment is carried out in the fourth week and atomic absorption spectrophotometry is applied to measure the calcium content of their dejecta and to estimate apparent absorptivity. Rats are killed in the twelfth week, and their thighbones are peeled. the results show that there is significant difference of the apparent absorptivity with different calcium intake. With the same content of calcium from nine kinds of calcium agents, the absorptivity is not significant different with an exception of those of active calcium, milk powder and oatmeal. Born density from the group of rats, which fed with diet with low level, middle level or high level of calcium, is obviously higher than that of rats fed with basic diet (P < 0.05). Born density of thighbone of the group of rats, which fed with diet with middle or high level of calcium content is not significantly different compared with that of rats fed with diet with calcium carbonate. The absorptivity of calcium is related with calcium content in diet. The effect of absorptivity of calcium agents tested is affirmative, but there is no difference of their effect in comparison with the calcium carbonate.