Ostel-D 70/2800 is a prescription medication combining Alendronic Acid (70 mg) and Vitamin D₃ (Cholecalciferol, 2800 IU), manufactured by Square Pharmaceuticals PLC in Bangladesh. It is primarily used to treat and prevent osteoporosis in postmenopausal women and men, aiming to increase bone mass and reduce the risk of fractures, particularly in the hip and spine.