强化钙与维生素D牛奶对北京城区小学女生骨量的影响

目的 :　探讨饮用钙与维生素 D强化牛奶对北京城区青春前期女生骨量的影响。方法 :　为期一年设有对照的双盲干预研究。将来自北京市西城区 9所小学平均年龄为 1 0 .1岁的女生 75 7名随机分为对照组 (n=2 5 9) :保持日常饮食 ;实验 1组 (n=2 3 8) :除日常饮食外 ,饮用钙强化牛奶 1 3 7ml/d,含钙 2 3 3 mg;实验 2组 (n=2 6 0 ) :除日常饮食外 ,饮用钙和维生素 D强化牛奶 1 3 7ml/d,其中钙 2 3 3 mg,VD 3 .3μg。使用 2 4 h回顾法了解食物摄入、体力活动问卷了解体力活动情况 ,用双能 X线吸收仪 (DEXA)测定全身和前臂骨量。结果 :　与干预前相比 ,实验组 2全身骨矿物密度 (BMD)的增长率显著高于实验 1组和对照组 (9.6 %、8.3 %和 8.0 % ,P=0 .0 0 2 ) ;实验 1组、实验 2组桡骨远端 1 /3处 BMC和骨面积的增长率显著高于对照组 (BMC:1 3 .0 %、1 2 .9%和1 1 .7% ,P=0 .0 1 6 ;骨面积 :2 .3 %、2 .0 %和 1 .5 % ,P=0 .0 1 0 ) ;实验 1组前臂远端 1 /1 0处 BMC和BMD的增长率显著高于对照组 (P=0 .0 0 7)。结论 :　饮用钙与维生素 D强化牛奶能促进青春前期女生骨量的增长 ,饮用钙和维生素 D强化牛奶促进骨量增长的作用比饮用钙强化牛奶明显

CALCIUM AND VITAMIN D FORTIFIED MILK SUPPLEMENTATION ON BONE MINERAL ACCRETION IN PRE-PUBERTAL GIRLS IN BEIJING

Objective: To investigate the effects of Ca and VD fortified milk supplementation on bone mineral acquisition in Chinese pre-pubertal girls. Methods: A one-year double-blind randomized intervention trial. Seven hundred and fifty-seven 10.1 years old girls from 9 elementary schools were divided randomly into three groups: Control group (n=259): routine diet without milk supplementation. Group 1 (n=238): routine diet supplemented with 137 ml Ca fortified milk daily. Group 2 (n=260): routine diet supplemented with 137 ml Ca and VD fortified milk daily. 24-hour recall dietary survey and physical activity assessment by questionnaire were adopted. Bone mass of forearm and total body were measured using Dual-energy X-ray Absorptionmetry (DEXA). Result: The increases of total body BMD was significantly greater in group 2 than group 1 and control group(9.6% vs 8.3% & 8.0%,respectively, P=0.002). Both group 1 and 2 had a greater increase of BMC and bone area at distal 1/3 radius than the control group (BMC: 13.0% & 12.9% vs 11.7%, respectively, P=0.016; bone area: 2.3% & 2.0% vs 1.5%, respectively, P=0.010). Group 1 had significantly higher percentage gain in distal 1/10 forearm BMC and BMD than in the control group (P=0.007). Conclusion: Ca and VD fortified milk supplementation in pre-pubertal girls resulted in greater bone mineral acquisition over one year, and was better than that fortified with Ca alone.