Despite the links between low calcium (Ca) intake and age-related bone loss, hypertension, and colon cancer, the majority of Western populations have average daily Ca intakes substantially below recommended daily allowances. Although dietary products are widely known as a rich and valuable source of Ca in the diet, consumption of diary products is low and has been decreasing because of perceptions of excess calories and fat in the diet, as well as taste aversions. During the last decade, a marked increase in the consumption of bottled waters has occurred. Since some of these waters are characterized by high concentrations of Ca, we have studied Ca bioavailability from a Ca-rich water, using 15 lactose intolerant male individuals as subjects, and compared such bioavailability to that from milk. We report herein that the bioavailability of Ca from the water was generally as good as or better than that from milk, a food product well known for its very high Ca bioavailability. Indeed, in eight of 15 subjects, there was a higher level of Ca absorption from mineral water than from milk; bioavailability was equal in five of 15 subjects; in contrast, in two of 15 subjects, the bioavailability of Ca absorption from milk was greater than that from the mineral water. The potential implications of this observation for the prevention and management of age-related bone loss are important for preventive medicine and indicate a new, important source of dietary Ca for lactose intolerant individuals.