The effects of a high-lipid diet on the intestinal transference of Ca2+ and the activities of intestinal enzymes were studied in ovariectomized rats. The plasma Ca2+ level and urinary loss of Ca2+ were also observed. Ovariectomy decreased both alkaline phosphatase (AP) and calcium ATPase (Ca(2+)-ATPase) activity, and also reduced the mucosal transference of Ca2+ in all parts of the small intestine. Although the plasma Ca2+ level did not change significantly, the urinary loss of Ca2+ was enhanced. A high-lipid diet supplement enhanced all these parameters in ovariectomized rats. It is therefore believed that a high-lipid diet may promote osteoporosis in ovariectomized rats as the result of Ca2+ transfer and enhanced urinary Ca2+ loss.