The use of calcium supplementation for the management of primary postmenopausal osteoporosis (PPMO) has increased significantly in the past few years. A review of the published data does not support calcium megadosing during postmenopause. Controlled studies showed no significant effect of calcium intake on mineral density of trabecular bone and a slight effect on cortical bone. Since PPMO is predominantly due to demineralization of trabecular bone, there is no justification for calcium megadosing in postmenopausal women. Soft tissue calcification is a serious risk factor during calcium megadosing under certain conditions. A total dietary program emphasizing magnesium instead of calcium for the management of PPMO takes into account the available data on the effects of magnesium, life-style and dietary habits on bone integrity and PPMO. When this dietary program was tested on 19 postmenopausal women on hormonal replacement therapy who were compared to 7 control postmenopausal women, a significant increase in mineral bone density of the calcaneous bone (BMD) was observed within one year. Fifteen of the 19 women had had BMD below the spine fracture threshold before treatment; within one year, only 7 of them still had BMD values below that threshold.