Alendronate sodium vitamin D3 tablets are a combination of two drugs, alendronate sodium and vitamin D3, whose main action is to antagonize osteoporosis. Osteoclasts play an important role in the process of osteoporosis. The increased activity of osteoclasts leads to increased destruction of bone trabeculae, thinning of bone cortex, decreased bone strength and increased bone fragility, resulting in easy fracture and the formation of osteoporosis. Alendronate sodium has an inhibitory effect on osteoclasts and can reverse or reduce osteoporosis. At the same time, the process of osteoporosis is accompanied by the loss of calcium, and anti-osteoporosis requires calcium supplementation. Vitamin D3 can promote the absorption of calcium and phosphorus in the gastrointestinal tract, which can synergistically carry out anti-osteoporosis, and these two drugs have synergistic effects. Alendronate has a significant stimulating effect on the esophagus, so after taking this drug, it is recommended to avoid lying down within half an hour and drink enough water to flush the drug into the stomach to avoid esophagitis.