AIM: We performed a retrospective analysis of a calcium hydroxide-containing calcium agent (TACHIKAWA DENKAI CALCIUM™: E-Ca) based on data of bone mineral density obtained by dual-energy X-ray absorptiometry (DXA) to clarify the relationship between bone mineral density and E-Ca intake on an empty stomach in those who regularly use E-Ca. RESULTS: We found the percentage of volunteers with their age-matched (AM) values of above 100% to be 89%, and also a moderate positive correlation between AM values and the intake period of E-Ca. CONCLUSION: Our findings demonstrate that AM values can be used as an effective indicator assessing osteogenesis by regularly administrated calcium agents which exert their effects after long-term use.