北京怀柔区13～15岁青少年钙代谢实验研究

A study of calcium metabolism for 13-15-years adolescents in Beijing Huairou district

目的通过钙代谢平衡实验推算我国北方青少年钙的适宜摄入量。方法将北京怀柔区304名13~15岁青少年分为4组,其中一组为对照组,另外三组每天补充含钙量分别为300 mg,600 mg,900 mg的奶粉。连续补钙1年后,从每个组男、女生各随机抽取4人,共32人,进行钙代谢实验。实验期共6天,收集研究对象在实验期间内摄入的饮食、排出的尿液和粪便,采用原子吸收分光光度法测定样品钙含量。结果研究对象钙的表观吸收率为63.2%,男生为67.4%,女生为58.7%,差异无统计学意义。全部研究对象的钙储留量为770 mg/d时达到平台期(男生为790 mg/d,女生为600 mg/d),对应的最低钙摄入量为1400 mg/d(男生为1320 mg/d,女生为1200 mg/d)。结论为满足钙储留量的增长以及使机体保持较高的钙吸收的需要,建议青春期少年要保证每日能摄入800 mg^1000 mg的钙。

Objective To calculate the proper calcium intake for teenagers in north China by using the calcium metabolic balance experiment.Methods A total of 304 young people aged from 13 to 15 years old in Beijing Huairou district were divided into 4 groups, including a control group and 3 intervention groups in which daily milk powder contenting 300 mg, 600 mg, and 900 mg calcium, respectively, was supplied.After 1-year calcium supplement, 4 males and 4 females were randomly recruited from each group.Therefore, 32 people participated in calcium metabolism experiment for six days.During the experiment, samples of food, feces, and urine were collected.Calcium content in samples was determined using the atomic absorption spectrophotometry. Results The calcium apparent absorption rate in the subjects was 63.2%, and 67.4 % in boys and 58.7% in girls, with no significant difference between boys and girls.Calcium retention platform for all subjects was 770 mg/d （790 mg/d in boys and 600 mg/d in girls） .The corresponding amount of minimum calcium intake was 1400 mg/d （1320 mg/d in boys and for 1200 mg/d in girls） .Conclusion In order to meet the need of growth of calcium retention and to enable the body to maintain a high level of calcium absorption, adolescents need daily calcium intake of 800 -1000 mg.