Calcium transport from mineral waters across Caco-2 cells

In the present study the absorption of calcium from 13 different mineral wa ters has been examined. For this purpose the mineral waters were first dige sted in vitro by simulating gastric and intestinal digestion. Afterward, th e absolute and fractional transport rates of calcium from these digested so lutions across human colon adenocarcinoma (Caco-2) cell monolayers grown on bicameral filters were measured. Results showed that the fractional transp ort rates for calcium lie between 1.65 and 6.72% after 90 min of incubation time. The absolute transport values varied between 90.4 and 624.7 pmol/(mi n.cm(2)). The transport values [pmol/(min.cm(2))] for calcium from the mine ral waters were in general not concentration dependent, showing neither sig ns of saturation kinetics nor unsaturable uptake mechanisms. In addition, t he fractional transport rates from mineral waters with similar calcium conc entrations were greatly different in some cases. On the basis of these resu lts, it can be concluded that calcium biovailability from mineral waters co uld vary dependent on probably several factors.