The invention is concerned with use of oral inorganic pyrophosphate for preventing and/or reducing tissue calcification, particularly soft tissue calcification, and/or diseases or disorders characterized by low plasma PPi levels, as, e.g., occurs in chronic kidney disease (CKD), end-stage renal disease (ESRD), generalized arterial calcification of infancy (GACI), Pseudoxanthoma elasticum (PXE), Arterial Calcification Due to Deficiency of CD73 (ACDC), Ehlers-Danlos syndrome, arteriosclerosis obliterans, venous calcifications, crystal deposition disorders, calcification resulting from neurological disorders, calcinosis universalis, calcinosis circumscripta, scleroderma, dermatomyositis, systemic lupus erythematosus, hyperparathyroidism, neoplasms, milk-alkali syndrome, hypervitaminosis D, tumoral calcinosis, hypophosphatemic rickets, ossification of the posterior longitudinal ligament of the spine, myocardial ischemia, joint calcification, heterotropic ossification of traumatized muscle, angioid streaks, diabetes mellitus type II, cardiovascular disorder, or atherosclerosis.