Enhanced absorption of calcium after oral administration of maltitol in the rat intestine

The enhancing effects of maltitol (alpha-D-glucopyranosyl-1,4-sorbitol) on absorption of calcium by the rat intestine have been studied by use of [Ca- 45]CaCl2 in-vivo. After intragastric administration of [Ca-45]CaCl2 solution with maltitol, p lasma Ca-45 concentration remained at the maximum level for more than 80 mi n, whereas for animals given [Ca-45]CaCl2 solution without maltitol, plasma Ca-45 concentration declined sharply after the peak. Determination of Ca-4 5 radioactivity remaining in the various segments of the gastrointestinal t ract revealed that administration of maltitol elicited slower gastric empty ing and slower intestinal transit, resulting in extensive Ca-45 distributio n along the small intestine throughout the experimental period. The luminal contents of the small intestine were significantly higher in rats given ma ltitol than in the control group. These results suggest that the enhancing action of maltitol on intestinal c alcium absorption could be attributed to reduced gastrointestinal calcium t ransit and increased luminal fluid content, presumably because of the osmot ic activity of maltitol; this would not only accelerate the dissolution of calcium into the increased luminal contents, but also enable a larger area of the small intestine to absorb calcium for a longer period of time.