FOSAMAX� PLUS D is indicated for the treatment of osteoporosis in postmenopausal women. In postmenopausal women, FOSAMAX PLUS D increases bone mass and reduces the incidence of fractures, including those of the hip and spine (vertebral compression fractures). Alendronate sodium is a bisphosphonate that acts as a specific inhibitor of osteoclast-mediated bone resorption. Bisphosphonates are synthetic analogs of pyrophosphate that bind to the hydroxyapatite found in bone. Cholecalciferol (vitamin D3) is a secosterol that is the natural precursor of the calcium-regulating hormone calcitriol (1,25 dihydroxyvitamin D3). Stop using alendronate and cholecalciferol and call your doctor at once if you have a serious side effect such as: chest pain- difficulty or pain when swallowing- pain or burning under the ribs or in the back- new or worsening heartburn- severe joint, bone, or muscle pain- new or unusual pain in your thigh or hip- or jaw pain, numbness,...