Assessment of Mineral and Bone Disorders in Kidney Transplant Recipients

This study is measuring bone health and mineral levels (like calcium and phosphorus) in three groups of people: those on long-term hemodialysis (kidney dialysis), kidney transplant recipients, and people with osteoporosis. The goal is to compare how kidney disease and transplantation affect bone strength and mineral metabolism. **You may be eligible if...** - (Dialysis group) You have been on hemodialysis for at least 12 months and are 20 to 70 years old - (Kidney transplant group) You received a kidney transplant at least 12 months ago and are 20 to 70 years old - (Osteoporosis group) You are a man or postmenopausal woman aged 50 to 70 with diagnosed primary osteopenia or osteoporosis **You may NOT be eligible if...** - (Dialysis group) You are currently receiving treatment for bone disease beyond calcium and vitamin D - You have an active cancer or are undergoing cancer treatment - You have had a serious infection recently Talk to your doctor to see if this trial is right for you.