Indigestible sugars are used in food production and pharmaceutical industry due to their desirable properties. The effects of mannitol on Ca and Mg absorption and retention in ovariectomized rats were evaluated. Five weeks old ovariectomized Wistar rats were given Ca, Mg-deficient diet for 28 days then fed a control diet or 8% mannitol diets for another 28 days. Feaces were collected twice for 72h to measure mineral absorption. On day 56, rats were slaughtered and cecal parameters were observed. Femurs were collected to measure mineral levels. Results were shown that mineral absorption and femoral mineral was significantly increased by mannitol feeding. Cecal parameters were significantly altered after mannitol consumption. In conclusion, Ca and Mg absorption and their retention were improved by cecal fermentation of mannitol in ovariectomized rats.