Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
J Bone Miner Res. 2011 Feb;26(2):364-72. doi: 10.1002/jbmr.196. Epub 2010 Aug 5.
Since its role in the prevention of osteoporosis in humans was proven some 30 years ago, calcium bioavailability has been the subject of numerous scientific studies. Recent technology allowing the production of a stable amorphous calcium carbonate (ACC) now enables a bioavailability analysis of this unique form of calcium. This study thus compares the solubility and fractional absorption of ACC, ACC with chitosan (ACC-C), and crystalline calcium carbonate (CCC). Solubility was evaluated by dissolving these preparations in dilute phosphoric acid. The results demonstrated that both ACC and ACC-C are more soluble than CCC. Fractional absorption was evaluated by intrinsically labeling calcium carbonate preparations with (45)Ca, orally administrated to rats using gelatin capsules. Fractional absorption was determined by evaluating the percentage of the administrated radioactive dose per milliliter that was measured in the serum, calcium absorption in the femur, and whole-body retention over a 34-hour period. Calcium serum analysis revealed that calcium absorption from ACC and ACC-C preparations was up to 40% higher than from CCC, whereas retention of ACC and ACC-C was up to 26.5% higher than CCC. Absorbed calcium in the femurs of ACC-administrated rats was 30% higher than in CCC-treated animals, whereas 15% more calcium was absorbed following ACC-C treatment than following CCC treatment. This study demonstrates the enhanced solubility and bioavailability of ACC over CCC. The use of stable ACC as a highly bioavailable dietary source for calcium is proposed based on the findings of this study.
自从 30 年前证明了其在预防人类骨质疏松症中的作用以来，钙的生物利用度一直是众多科学研究的主题。最近的技术允许生产稳定的无定形碳酸钙（ACC），现在可以对这种独特形式的钙进行生物利用度分析。因此，本研究比较了 ACC、与壳聚糖结合的 ACC（ACC-C）和结晶碳酸钙（CCC）的溶解度和分数吸收。通过将这些制剂溶解在稀磷酸中评估溶解度。结果表明，ACC 和 ACC-C 的溶解度均高于 CCC。通过用（45）Ca 内在标记碳酸钙制剂，并用明胶胶囊口服给予大鼠来评估分数吸收。通过评估每毫升血清中测量的放射性剂量的百分比、股骨中的钙吸收和 34 小时期间的全身保留来确定分数吸收。钙血清分析表明，从 ACC 和 ACC-C 制剂中吸收的钙比从 CCC 制剂中吸收的钙高 40%，而 ACC 和 ACC-C 的保留率比 CCC 高 26.5%。ACC 处理的大鼠股骨中吸收的钙比 CCC 处理的动物高 30%，而 ACC-C 处理后吸收的钙比 CCC 处理后多 15%。这项研究证明了 ACC 比 CCC 具有更高的溶解度和生物利用度。根据这项研究的结果，建议将稳定的 ACC 用作钙的高生物利用度膳食来源。
