This is a randomized, double-blind, active-controlled study to evaluate the efficacy and safety of amorphous calcium carbonate in rheumatoid arthritis patients with osteopenia or osteoporosis, compared to crystalized calcium carbonate.~A total of 180 subjects will be enrolled into this study. Eligible subjects will be randomized to receive amorphous calcium carbonate (ACC group) or crystalized calcium carbonate (CCC group) with 1:1 allocation. Randomization will be stratified by the use of biologics. The study product, 2 tablets (400mg calcium element), will be taken twice daily approximately 30 minutes after breakfast and dinner during 12-month treatment period. Additional 600 IU vitamin D3 will be also received with investigational product after breakfast.~The study will consist of 7 clinical visits. Subjects will come to the clinics at Visit 1 (screening visit), Visit 2 (randomization, regimen start), Visit 3 to 6 (follow-up visits), and Visit 7 (post-treatment follow-up visits) according to the pre-defined schedule.~The DXA score, and BTM (P1NP, CTX) from fasting serum samples, and FRAX score will be collected. The treatment-emergent adverse events for safety endpoints will be also recorded.
DensityTM, an amorphous calcium carbonate (ACC) imported by Universal Integrated Corporation, is tried to demonstrate its efficacy and safety in rheumatoid arthritis patient with osteopenia or osteoporosis, compared to crystalized calcium carbonate (CCC).