青春前期女童钙代谢实验研究

目的:研究我国青春前期女童钙代谢状况,初步探讨该时期女童钙需要量。方法:选择49名处于生长突增期、未月经初潮的青春前期女童,采用经典钙代谢实验方法,在600～1500mg/d范围内设计4个不同的钙摄入剂量组,观察研究对象的钙代谢状况。结果:在600～1500mg/d钙摄入量范围内,各组对象钙表观钙吸收率未发现差别,平均吸收率为(53±0.12)%(范围52%～55%)。采用非线性回归模型对钙摄入量和钙储留量的关系进行拟合,钙摄入量在500mg/d时,钙储留量处于较低水平,钙摄入量在500～1000mg/d时,储留量快速增加,当钙摄入量达到1100mg/d时,钙储留量稳定在500mg/d左右的平台水平。结论:我国青春前期女童钙的表观吸收率为(53±0.12)%;青春前期女童达到最大钙储留量的最低钙摄入量是1100mg/d。

STUDY OF CALCIUM METABOLISM IN PREMENARCHE CHINESE GIRLS

Objective:To investigate the characteristics of calcium metabolism and identify the calcium intake that produces plateau retention in premenarche Chinese girls. Method:Forty-nine healthy premenarche Chinese girls (9-11.5 y) were recruited, and divided into four groups respectively receiving one of four different doses of calcium intakes for 6 d, 600 mg (usual diet),900 mg (containing 250 ml milk),1 200 mg (containing 250 ml milk and 750 mg CaCO3) and 1 500 mg calcium (250 ml milk and 1500 mg CaCO3) per day. Calium in 3-day urine and stool,and 3-d duplicated food samples were collected to assess the calcium equilibrium during the treatment period. Results: There were no significant differences in apparent calcium absorption among the four groups (55%, 53%, 52% and 52%). The relationship between calcium intake and calcium retention was fitted into a non-liner regression model which showed that the calcium retention was approaching the plateau when calcium intake reached 1100mg/d. Conclusion: The apparent calcium absorption was 53%±0.12% in Chinese premenarche girls with dietary calcium intakes ranged between 600 to 1500 mg/d. Calcium retention approached its plateau when calcium intake reached 1 100 mg/d in Chinese premenarche girls.