Phosphate deficiency

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 $\rightarrow$ 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