Harvey J A, Kenny P, Poindexter J, Pak C Y
Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas 75235.
J Am Coll Nutr. 1990 Dec;9(6):583-7. doi: 10.1080/07315724.1990.10720413.
Calcium absorption from calcium citrate was compared with that obtained from calcium carbonate in 20 normal women. It was measured by external forearm counting technique, where the ratio of forearm radioactivity after an oral dose of labeled calcium salt (containing 500 mg calcium) and after an intravenous injection of trace radiocalcium represented fractional calcium absorption. The fractional calcium absorption from calcium citrate was 39.2 +/- 8.6%, which was significantly higher than the 31.2 +/- 9.4% derived from calcium carbonate (p less than 0.001). Seventeen subjects displayed greater calcium absorption from calcium citrate. The remaining three patients, with a lower calcium absorption from the citrate salt, had high levels of calcium absorption from calcium carbonate. It is concluded that calcium is better absorbed from calcium citrate than calcium carbonate when these salts are taken on an empty stomach in most women. The exception might be those with optimum calcium absorption from calcium carbonate.
在20名正常女性中，对柠檬酸钙的钙吸收情况与碳酸钙的钙吸收情况进行了比较。采用前臂外部计数技术进行测量，口服一定剂量的标记钙盐（含500毫克钙）后前臂放射性与静脉注射微量放射性钙后前臂放射性的比值代表钙的吸收分数。柠檬酸钙的钙吸收分数为39.2±8.6%，显著高于碳酸钙的31.2±9.4%（p<0.001）。17名受试者从柠檬酸钙中吸收的钙更多。其余三名患者从柠檬酸盐中吸收的钙较低，但从碳酸钙中吸收的钙水平较高。得出的结论是，在大多数女性空腹服用这些盐时，柠檬酸钙的钙吸收比碳酸钙更好。例外情况可能是那些从碳酸钙中能实现最佳钙吸收的女性。
