5th April 2024

Management

Treatment depends on the cause, severity and duration of low phosphate. Mild hypophosphatemia can be treated with oral phosphate replacement. Parenteral phosphate is usually indicated when levels reach < 0.3 mmol/L with close monitoring of phosphate, calcium and renal function as there is a risk of hypocalcaemia, over treatment resulting in hyperphosphatemia and hyperkalemia. Those with poor renal function are at increased risk from intravenous replacement. 

Where low phosphate is secondary to Coeliac disease or Crohn’s, the underlying condition should be treated. Similarly, problems with alcohol dependency or eating disorders need appropriate input from specialist teams and in hyperparathyroidism, the causative tumour should be identified and removed.  In oncogenic osteomalacia, phosphate supplements are useful until the tumour has been found and removed. 

In vitamin D deficiency, oral vitamin D is usually sufficient but in severe renal disease where the kidneys are unable to convert hepatic hydroxyvitamin D3 to 1, 25 dihydroxy vitamin D3, active vitamin D should be given.