补钙对低钙膳儿童骨矿物质含量的影响

EFFECT OF CAL CIUM SUPPLEMENTATION ON BONE MINERAL CONTENT IN CHILDREN ACCUSTOMED TO LOW CALCIUM DIET

江门市１６２名７周岁（男童８７人，女童７５人）低钙膳食习惯的儿童，随机双盲分为两组。实验组以碳酸钙形式补给，每天供给钙３００ｍｇ，对照组给予同外形的安慰剂，持续１８个月。每６个月测定上臂的骨矿物质含量（ＢＭＣ）、骨矿物质含量与骨宽的比值（ＢＭＣ／ＢＷ）一次。了解膳食的基础摄入情况和测定２５－羟维生素Ｄ３的生理活性等。结果：１８个月后，实验组与对照组比有明显差异，ＢＭＣ（１６．５％：１３，９７％，Ｐ＝０．０２），ＢＭＣ／ＢＷ（９．４５％：６．３１％，Ｐ＝０．０００８）。表明增加钙的摄入对骨的获得有一定作用，但对身高的增长不明显。

randomised,double-blind calcium supplementation trial was underta-ken for 18 months to determine its effects on bone acquisition and heightinerement in 162 7-year-old Chinese children (87 1boys ,75 girls )with habi-tually low calcium intake(280mg/d).Bone mineral content (BMC) of distalone-third radius areal bone width(BMC/BW),and height were evaluatedsix-monthly.Baseline ditetary intakes,serum 25-hydroxy-vitamin D and physi-cal activity were determined.The experimental group received 300mg/d calci-um by calcium-carbonate,control group received plecebo tablets.After 18months, the experimental group had significantly greater gains in BMC(16.5%vs13.97%,P<0.02) and BMC/BM(9.45%vs 6.31%,P<0.001)wthn compar-ed with the control.The findings confirmed a positive effect of calciumintake on bone acquisition, but it had no benefit on height increment.Whe-ther a higher bone mass attained at age 8-9 years would be maintainedand beneficial to future peak bone mass required longitudinal investigation.Further study was warranted to determine calcium requirements for Chinesechildren.