Factors that affect the serum phosphorus level
| Increase phosphorus | Decrease phosphorus |
|---|---|
| Renal failure (decreases urinary excretion) Vitamin D (increases intestinal absorption) Increased phosphate load (from diet, drugs, cell lysis) | Fibroblast growth factor 23 (increases urinary excretion, decreases intestinal absorption, decreases parathyroid hormone) Dietary restriction Phosphate binders |
| Parathyroid hormone increases phosphorus release from the bone while increasing its excretion from the kidney, so the plasma levels are minimally affected. | |