The kidneys and the bones are both involved in calcium homeostasis; therefore, impaired renal function leads to defective calcium homeostasis and renal osteodystrophy, in the young as in the old. Chronic renal insufficiency induces osteoporosis, osteomalacia and secondary hyperparathyroidism by means of deficiencies in vitamin D metabolism. Observational studies have shown that the survival of patients with HPT may be improved by treatment with analogues of vitamin D, given while the patients are on dialysis. Chronic kidney disease (CKD) and end-stage kidney disease (ESKD) with the increased risk of fracture are both the subjects of growing international concern. The prevalence of both is expected to increase within the next decade together with the ageing of the populations in many parts of the world, and many studies of these patients, both completed and ongoing, deal with the therapy and prevention of osteoporosis and fractures, including treatment with bisphosphonates. Another major consideration, also from an epidemiological point of view, is the close association of CKD with risk of cardiovascular disorders, which of course are also increased in the older populations and may be associated with osteopenia/osteoporosis. The survival of patients with CKD has benefited from therapy with calcitriol, and in recent years, the more potent analogues have shown additional advantages. These beneficial effects are also due to improvements in the cardiovascular system. It is now hoped that early therapy will benefit the kidney, slow progression of disease and postpone the necessity for haemodialysis and transplantation.