Wynckel A, Hanrotel C, Wuillai A, Chanard J
Service de Néphrologie, Centre Hospitalier et Universitaire, Reims, France.
Miner Electrolyte Metab. 1997;23(2):88-92.
Little is known about the bioavailability of calcium in water and various beverages. Some mineral waters contain large amounts of calcium that could compensate for insufficient consumption of dairy products. The fractional intestinal absorption of calcium (FCA) was measured in 12 healthy adult volunteers, using a trace dose of radiocalcium and 200 mg of calcium carrier, part of which was calcium contained in mineral water. Measurements were performed in fasting subjects consuming a standard breakfast. In all the subjects, three mineral waters with a calcium concentration of 10.4, 78, and 467 mg/l, respectively, were tested. Calcium absorption occurred with the same kinetics for each of the mineral waters tested, and within 2 h of the oral dose, equilibrium was reached between absorbed calcium and calcium remaining in the gastrointestinal tract, which resulted in a constant FCA value. This level comprising between 34.1 and 37.0% was independent of the daily calcium consumption and the chemical content of the mineral water. In conclusion, calcium contained in mineral waters in available for intestinal absorption. In a given normal subject, the only rate-limiting factor for FCA is the amount of total calcium given with foods and drinks. Mineral waters containing calcium are recommended as a supplemental source of calcium to achieve optimal calcium requirements, especially in aged people with lactose intolerance.
关于水中和各类饮品中钙的生物利用度，人们了解甚少。一些矿泉水中含有大量钙，可弥补乳制品摄入不足的问题。采用微量放射性钙和200毫克钙载体（其中一部分是矿泉水中所含的钙），对12名健康成年志愿者的肠道钙吸收分数（FCA）进行了测量。测量在食用标准早餐的空腹受试者中进行。对所有受试者分别测试了三种钙浓度分别为10.4、78和467毫克/升的矿泉水。所测试的每种矿泉水的钙吸收动力学相同，口服剂量后2小时内，吸收的钙与胃肠道中残留的钙达到平衡，从而得出恒定的FCA值。该水平在34.1%至37.0%之间，与每日钙摄入量和矿泉水的化学成分无关。总之，矿泉水中的钙可被肠道吸收。在特定的正常受试者中，FCA的唯一限速因素是食物和饮品中钙的总量。推荐饮用含钙的矿泉水作为钙的补充来源，以满足最佳钙需求, 尤其是对乳糖不耐受的老年人。
