补充钙剂对青春期骨矿含量的影响

为研究补充钙剂对青少年骨矿含量以及体格发育的影响 ,选取 1 61例 9～ 2 0岁健康青少年 ,按性别和性发育程度分为补钙组和对照组。实验前后评价两组膳食钙摄入量、运动量水平、性发育程度 ,并测定两组青少年身高、体重和桡骨远端 1 3处骨矿含量、骨宽和血清总碱性磷酸酶水平。结果表明本组青少年膳食钙摄入量低于每日膳食钙参考摄入量的适宜摄入量水平 ,补充钙剂对青少年身高、体重无明显影响 ;骨矿含量增长除女性青春期后期有显著性差异外 ,其余各组增长与对照组比较无显著性。结果提示 ,青春期存在体格快速发育和骨量迅速积累的特点 ,补充钙剂对骨矿含量的增长作用有限 ,对体格发育也无明显影响 ;在女性骨量增长较少阶段补充钙剂则可能有助于骨矿含量的增加 ,且这种作用可能通过降低骨代谢率实现

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 300mg 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 500mg/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.