Cause:Malnutrition; aluminum-binding antacids; iv glucose, which drives intracellularly; renal tubular damage from hypokalemia, osmotic diuresis, or Fanconi’s. In types without cell injury like acute DKA, hyperalimentation, or acute respiratory alkalosis, no bad consequences occur because total body PO₄ depletion has not occurred (Nejm 1985;313:447)

Sx:Confusion, weakness

Bleeding (impaired platelet function), infections (impaired granulocyte function), rhabdomyolysis

Lab: PO₄ low

Rx: 2.5 mg elemental phosphorus/kg in NS over 12-h iv, or po w NeutroPhos