Goals: The study was designed to determine whether high-calciummineral water is an efficient additional source of dictary calcium, optimizinga method for calcium determination never used for mineralwaters.Background: It is generally agreed that an adequate calcium intakeis neccssary for the acquisition of an ideal peak bone mass and forthe maintenance of the bone mineral density in adults, in postmenopausalwomen, and in the elderly. Mineral waters are calorie free, andsome, with high calcium levels, might be significant sources of calcium.Study: The availability of the calcium contained in a high-calciummineral water was measured in 27 healthy subjects. In 8 subjects thecalcium availability of the water was compared with the calciumavailability ingested with milk at the same calcium load. Milk andwater were labeled extrinsically with 30 mg 44Ca. Fractional absorptionfrom the oral dose was determined from plasma samples usingICP-MS technique.Results: At an ingested calcium load of 3.18 mmol, percentage ofabsorption for water averaged 22.53 ± 2.53 (mean ± SO) for men,22.57 ± 2.10 (mean ± SD) for premenopausal women and 21.62 ±3.12 (mean ±SO) for postmenopausaI women. Percentage absorptionfrom milk was 23.15 ± 4.06 (mean ±SO).Discussion: The calcium from the mineral water is thus highly bioavailable,at least as bioavailable as milk calcium, and ICP-MS appearsto represent a reliable and reproducible method for calcium absorptionfrom alimentary sources.

Università degli studi di Firenze – Dipartimento di Medicina Interna ed Endocrinologia – Prof.ssa M.Luisa Brandi – 2004