Phosphate

The normal reference range for Phosphate is Adult phosphate is typically 0.75-1.50 mmol/L (children run higher because of bone growth). Phosphate is regulated together with calcium by parathyroid hormone and vitamin D, so the two are read together.. Reference ranges may vary between laboratories, so always consult your healthcare provider for interpretation.

Helps assess kidney function, bone metabolism, and certain metabolic disorders.

High phosphate (hyperphosphataemia) is most commonly caused by reduced kidney clearance in chronic kidney disease — a key driver of bone and vascular problems in kidney patients. Other causes include an underactive parathyroid, excess vitamin D, and the massive cell breakdown of tumour lysis syndrome or rhabdomyolysis. It often mirrors a low calcium.

Low phosphate (hypophosphataemia) is classically seen in refeeding syndrome, when nutrition is reintroduced after starvation — a potentially dangerous shift that must be anticipated. Other causes include an overactive parathyroid, vitamin D deficiency, excess alcohol, recovery from diabetic ketoacidosis, and phosphate-binding antacids. Severe depletion causes muscle weakness and impaired breathing.

Phosphate is measured with calcium and kidney function when assessing bone disease, parathyroid disorders or chronic kidney disease, and is monitored closely when feeding malnourished patients to catch refeeding syndrome early. It is not part of every routine panel.