microgravity effects on bone density

Microgravity, such as in space, reduces the mechanical stress on bones, leading to decreased stimulation for bone maintenance. Without normal weight-bearing activity, bones lose minerals like calcium, resulting in decreased bone density and strength, increasing fracture risk. This process, similar to osteoporosis on Earth but accelerated, occurs because bones rely on regular stress to stay healthy. Re-entering Earth's gravity prompts the body to rebuild bone density, but recovery can take time, and prolonged space exposure poses significant challenges to skeletal health.