[Effects of different form calcium on growth and tissue calcium level in rats]

In order to solve the problem of calcium deficiency and to look for economic and efficient source of calcium, the effects of calcium carbonate, active calcium and calcium lactate on growth, development and tissue calcium level in rats were compared. Fifty-six 3-week old weaning rats were fed with calcium deficient diet (containing vitamin D 500 IU per kg diet) for 3 weeks, and then were divided into four groups randomly with 14 rats in each group, half male and half female. The diet of control group (A) was the basic diet, while the three experiment diets were supplemented with calcium carbonate (B), active calcium (C) and calcium lactate (D) (3000 mg calcium per kg diet), respectively. The experiment term was 12 weeks. The results showed that the body weight and length of calcium supplemented group were significantly higher than that of control group (P<0.05). Among the calcium supplemented groups, no significant differences were observed except the difference of body length between the group D and the group A in female. Calcium deficiency dramatically hindered the development with reduced dietary intake and decreased food consumption efficiency. The calcium levels in plasma, red blood cells and liver were significantly higher in the supplemented groups than that in the control group (P<0.05), however, there was no difference among the supplemented groups. No significant difference of calcium levels in muscle and heart was observed among all groups. Based on needs for reaching the RDA with additional 400 mg/d from present calcium status in Chinese population, the calcium carbonate is the most economic one and the ideal calcium source for supplementation.