Phosphorus And Nutrition In Chronic Kidney Disease
Daily phosphorus ingestion is approximately 1200 mg, of which 950 mg are absorbed. Around 29% of body phosphorus is located in bone, and less than 1% is in the blood, which is the phosphorus that is quantified in clinical practice. Most phosphorus (70%) is located intracellularly and is interchangeable. Phosphorus is removed by two systems, the gastrointestinal tract, (150 mg/day) and the urine (800 mg/day) . Ingestion of phosphorus by an individual with normal renal function results in immediate phosphaturia probably mediated by phosphatonins of intestinal origin . A positive phosphorus balance recruits other phosphatonins. The first one, faster and transient, is parathyroid hormone (PTH) and the second one, slower and lasting, is Fibroblast Growth Factor 23 (FGF23).