The effects of a total bone extract (TBE), a new mineral preparation made from bovine bone rendered soluble by lactic acid and citric acid under decompression, on the bone metabolism and apparent calcium absorption were examined for an ovariectomized (OVX) rat model of osteoporosis. The apparent calcium absorption from TBE was significantly higher than that from calcium carbonate. There were no significant differences in serum biochemical indices. Although there were no significant differences in the dry weight, ash and calcium content in the tibia, or in the bone mineral density of the femur, TBE feeding increased the cortical thickness index of the femur. A positive effect of TBE on bone formation is thus suggested.