Low intake - Malnutrition, malabsorption, Alcoholism

Excess loss - hyperparathyroidism, renal tubular damage (Fanconi syndrome), diarrhoea

Extracellular/intracellular fluid redistribution - alkalosis, refeeding

Refeeding syndrome

  • (\downarrow) Insulin, (\uparrow) glucagon. Fat and protein metabolism. Intracellular stores of electrolytes used up
  • Upon refeeding (\uparrow) Insulin, (\uparrow) glycolysis, requiring K, PO4 and magnesium movement into cells with glucose.
  • This causes severe hypokalaemia, hypophosphatemia and Hypomagnesemia heart dysfunction and resp failure

Signs and symptoms of low PO4

  • Haemolysis, thrombocytopenia and poor granulocyte function
  • Severe muscle weakness, respiratory muscle failure and rhabdomyolysis

Treatment with oral or IV phosphate