The bone and mineral metabolism group of the Argentina Nephrology Society (Sociedad Argentina de Nefrolog铆a) () has produced a consensus document to help the nephrologist in the management of mineral metabolism of the patient with chronic kidney disease, adapted to the reality of Argentina. It has taken into account the new definitions and a more integrated classification system than that recently proposed by the KDIGO (Kidney Disease Improving Global Outcomes) Foundation. In this part several chapters are presented. In this article we review the introduction to the working consensus and the first chapter that deals with bone and mineral metabolism in the treatment of hyperphosphatemia in chronic kidney disease stage 3鈥?.