Department of Nutritional Sciences, Rutgers University, 96 Lipman Drive, New Brunswick, NJ 08901-8525, USA.
Osteoporos Int. 2012 Nov;23(11):2607-14. doi: 10.1007/s00198-012-1901-5. Epub 2012 Jan 27.
The goal in this study was to examine the hormonal and dietary predictors of true fractional Ca absorption (TFCA) in adult women and to determine whether TFCA differs due to body weight. Results showed that TFCA is higher in obese individuals and dietary fat, estradiol, and 1,25-dihydroxy vitamin D are the most significant positive predictors of TFCA in adult women.
Calcium absorption is an important determinant of calcium balance and is influenced by several factors. Previous studies have identified that age, intake of protein, fat and fiber, and hormones such as 1, 25-dihyroxyvitamin D (1,25(OH)(2)D(3)) influence absorption. The determinants of TFCA using the double isotope method, the gold standard estimate of absorption, have not been examined previously in adult women nor has the role of obesity been addressed.
In this study, we examined the hormonal and dietary predictors of TFCA in adult women with a wide range of age, body weights, and nutrient intake. TFCA was measured using dual stable isotope ((42)Ca and (43)Ca) technique. Serum was analyzed for bone-regulating hormones, and dietary information was obtained through food records. The independent dietary factors and hormonal predictors (25-hydroxyvitamin D, 1,25(OH)(2)D(3), parathyroid hormone, and estradiol) of TFCA were analyzed using multiple regression analysis.
Two hundred twenty-nine women aged 54 ± 11 years old (24-75 years) and with BMI of 31 ± 7.0 kg/m(2) were eligible and were categorized into tertiles of body mass index (BMI) into leaner, overweight, and obese. In the entire group of women, total fat intake, estradiol, and 1,25(OH)(2)D(3) are significant positive predictors (p < 0.05). As expected, age is a significant negative predictor of TFCA (R (2) = 26%). TFCA is higher in obese women compared to non-obese women (p < 0.05).
Together, these data show that dietary fat is the most significant positive predictor of TFCA which may have implications for dietary intake for non-obese individuals who are more likely to have lower and potentially compromised Ca absorption.
本研究旨在探讨女性真分数钙吸收（TFCA）的激素和饮食预测因子，并确定 TFCA 是否因体重而有所不同。
肥胖个体的 TFCA 较高，膳食脂肪、雌二醇和 1,25-二羟维生素 D 是成年女性 TFCA 的最重要正向预测因子。
钙吸收是钙平衡的重要决定因素，受多种因素影响。先前的研究表明，年龄、蛋白质、脂肪和纤维的摄入量以及 1,25-二羟维生素 D（1,25(OH)(2)D(3)）等激素都会影响吸收。此前尚未在成年女性中使用双同位素法（TFCA 的金标准估计值）来检测 TFCA 的决定因素，也未研究肥胖的作用。
本研究中，我们使用双稳定同位素（(42)Ca 和 (43)Ca）技术，检测了年龄、体重和营养素摄入量范围广泛的成年女性的 TFCA 激素和饮食预测因子。通过食物记录获取血清骨调节激素和膳食信息。使用多元回归分析分析 TFCA 的独立膳食因素和激素预测因子（25-羟维生素 D、1,25(OH)(2)D(3)、甲状旁腺激素和雌二醇）。
共有 229 名年龄 54 ± 11 岁（24-75 岁）、BMI 为 31 ± 7.0 kg/m(2)的女性符合条件，并按 BMI 分为更瘦、超重和肥胖三组。在整个女性组中，总脂肪摄入量、雌二醇和 1,25(OH)(2)D(3)是显著的正向预测因子（p < 0.05）。如预期的那样，年龄是 TFCA 的显著负向预测因子（R (2) = 26%）。与非肥胖女性相比，肥胖女性的 TFCA 更高（p < 0.05）。
这些数据表明，膳食脂肪是 TFCA 的最重要正向预测因子，这可能对那些脂肪摄入量较低、钙吸收可能受损的非肥胖个体的饮食摄入有意义。
