[Effects of calcium supplementation on bone mineral accretion in adolescents]

The trial is conducted to evaluate the effects of calcium on bone mineral accretion in adolescents. 161 healthy adolescents aged of 9 to 20 year-old are recruited and are randomly divided into experimental groups in which 300 mg Ca is supplemented per day for each participant and control group. The dietary calcium, physical activity, SMR, distal one-third radial bone mineral content (BMC), bone width (BW), height, weight and serum total ALP are measured at both the beginning and the end of the trial. It is found that the average calcium intake from dietary sources is 500 mg/d in both groups. Increasing daily calcium intake via calcium supplementation in adolescents results in a moderate increases of BMC, and there is a significant increase of BMC in the females during the late adolescence. No significant differences in anthropometry are observed between the two groups at the end of the study while the increase of serum ALP level in the females in experiment group is significantly lower than that in the control group during the late adolescence. It is concluded that during the pubertal years when the BMC accretion is evident, there are no significant differences in bone mass accrual between the two groups. While in the females, calcium supplementation may help enhance the bone mineral accrual during late adolescence when the BMC accretion is remarkably reduced.