Calcium retention in relation to calcium intake and postmenarcheal age in adolescent females
Calcium retention in relation to calcium intake and postmenarcheal age in adolescent females
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DOI：
10.1093/ajcn/66.2.327
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发表时间：
1997-08-01
影响因子：
7.1
通讯作者：
Weaver, CM
中科院分区：
文献类型：
--
作者：
Jackman, LA;Millane, SS;Weaver, CM
在青春期达到最大钙潴留可能会影响峰值骨量的大小，从而降低骨质疏松症的风险。一般认为，钙潴留在一定的钙摄入量下会达到一个平台。为了检验这一假设，在35名平均（+/- SD）年龄为12.7 +/- 1.2岁（范围：12-15岁）的女性中测量钙平衡，这些女性的钙摄入量为841 +/- 153至2173 +/- 149 mg Ca/d。受试者吃基础饮食，其中包括含有不同量柠檬酸苹果酸钙的强化饮料。二十一名受试者进行了研究，在两个膳食钙摄入量与使用交叉设计。数据分析中纳入了先前在14名受试者中进行的研究结果，这些受试者仅摄入一种钙。钙潴留被建模为钙摄入量的非线性函数，其中包括代表平均最大保留的参数。平均最大钙潴留为473 mg/d（95% CI：245，701 mg Ca/d）。在较高的绝经后年龄，最大钙潴留较低，但所需的摄入量，以实现这一点也没有受到影响。钙摄入量分别解释了粪便和尿钙排泄变化的79%和6%。摄入1200 mg Ca/d（1989年公布的钙的推荐膳食允许量）导致平均钙保留为最大值的57%（95%; CI：25%，89%）。1300 mg Ca/d的摄入量是允许一些青少年女性达到100%最大钙潴留的最小摄入量（95% CI：26%，100%）。这些数据支持这样的观点，即钙潴留在一定的钙摄入量下达到平台，尽管在摄入量> 2 g/d时钙潴留继续增加。
Achievement of maximal calcium retention during adolescence may influence the magnitude of peak bone mass and subsequently lower the risk of osteoporosis. Calcium retention is generally considered to reach a plateau at a certain calcium intake. To test this hypothesis, calcium balance was measured in 35 females with a mean (+/- SD) age of 12.7 +/- 1.2 y (range: 12-15 y) who consumed from 841 +/- 153 to 2173 +/- 149 mg Ca/d. Subjects ate a basal diet that included a fortified beverage containing different amounts of calcium citrate malate. Twenty-one subjects were studied at two dietary calcium intakes with use of a crossover design. Results from a previous study in 14 subjects who were studied at only one calcium intake were included in the data analysis. Calcium retention was modeled as a nonlinear function of calcium intake that included a parameter representing mean maximal retention. Mean maximal calcium retention was 473 mg/d (95% CI: 245, 701 mg Ca/d). At higher postmenarcheal ages, maximal calcium retention was lower but the intake required to achieve this was nor affected. Calcium intake explained 79% and 6%, respectively, of the variation in fecal and urinary calcium excretion. Intake of 1200 mg Ca/d, the recommended dietary allowance for calcium published in 1989, resulted in a mean calcium retention that was 57% of the maximal value (95%; CI: 25%, 89%). Intake of 1300 mg Ca/d was the smallest intake that allowed some adolescent females to achieve 100% of maximal calcium retention (95% CI: 26%, 100%). These data support the idea that calcium retention plateaus at a certain calcium intake although it continues to increase at intakes > 2 g/d.