Postmenopausal women (aged from 55 - 67 y old) living Hanoi were divided into 4 groups and received daily one wafer fortified with different doses and kinds 0f Ca and D3. Group 1 (n=44) received a wafer contained 500 mg ca carbonate & 100 IU D3; group 2 (n=46), received a wafer contained 500 mg Ca Gluconate & 100 IU D3; group 3 (n=49) received a wafer contained 1000 mg ca carbonate & 200 IU D3; group 4 (n=49) received a wafer non-fortified (placebo).