MLT GlobePhosphate (inorganic phosphorus)
Electrolytes · also called PO₄, Phosphorus, Pi
What it measures
Serum phosphate reflects the inorganic phosphorus needed for bone mineral and cellular energy. It is measured with calcium in kidney, bone, parathyroid and nutritional disorders.
Specimen and preparation
- Specimen: Serum or lithium-heparin plasma
- Tube: Gold top
- Preparation: Fasting sample preferred; separate promptly and avoid haemolysis.
Reference range
| Group | Range |
|---|---|
| Adult | 2.5–4.5 (0.81–1.45) mg/dL (mmol/L) |
| Child | 4.0–7.0 (1.29–2.26) mg/dL (mmol/L) |
Reference ranges differ between laboratories, methods and populations. Always use the range printed on your own lab report.
Causes of high values
- Chronic kidney disease
- Hypoparathyroidism
- Tumour lysis and rhabdomyolysis
- Vitamin D excess
- Haemolysed or delayed sample
Causes of low values
- Refeeding syndrome
- Primary hyperparathyroidism
- Vitamin D deficiency
- Alcohol use disorder
- DKA treatment and respiratory alkalosis
Method
Colorimetric (phosphomolybdate, UV)
Good to know
Phosphate is naturally higher in growing children. Severe low phosphate (<1 mg/dL) can cause muscle weakness and respiratory failure.
Related tests
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