Healthy kidneys activate vitamin D. The activated form of vitamin D is called calcitriol. Calcitriol helps the body absorb calcium. Working together, calcitriol helps maintain normal PTH levels, and they carefully balance calcium in your system. When kidneys fail, they stop converting inactive vitamin D to calcitriol. Your body is unable to absorb calcium from food, so it “borrows” the calcium it needs from the greatest calcium storage depot. Renal osteodystrophy (ROD), also known as uremic osteopathy, is the constellation of musculoskeletal abnormalities that occur in patients with chronic renal failure, due to concurrent and superimposed. demineralization: usually subperiosteal, however it may also involve joint margins, endosteal, subchondral, subligamentous areas, cortical bone, or trabeculae