What is the Phosphate test?

The Phosphate blood test measures the level of inorganic phosphate in the blood, a mineral essential for bone formation, energy production (ATP), and cell function. Phosphate works closely with calcium, vitamin D, and parathyroid hormone to maintain skeletal and metabolic balance.

Most phosphate is stored in bones and teeth, with smaller amounts circulating in the blood. Levels are tightly regulated by the kidneys, intestines, and hormones, meaning abnormal results can indicate underlying systemic issues.

This test is commonly used alongside calcium, parathyroid hormone, vitamin D, and kidney function tests to assess mineral metabolism and bone health.

Why do I need a test for Phosphate?

Phosphate testing is important when investigating bone disorders, kidney disease, or unexplained muscle or neurological symptoms. Both low and high phosphate levels can disrupt normal cellular function and bone integrity.

It is particularly useful for people with chronic kidney disease, hormonal imbalances, malnutrition, or conditions affecting absorption or excretion of minerals.

You may benefit from this test if you experience:

• Bone pain or bone weakness

• Muscle weakness or cramps

• Fatigue or low energy

• Fractures or osteoporosis

• Abnormal calcium or vitamin D levels

• Kidney disease or kidney stones

• Poor nutrition or malabsorption

• Suspected parathyroid disorders

Benefits of the Phosphate test

1. Assesses bone mineral balance
   Phosphate is essential for healthy bone structure and strength.

2. Supports kidney function evaluation
   Abnormal levels often reflect impaired renal regulation.

3. Complements calcium and PTH testing
   Helps interpret mineral and hormonal balance.

4. Identifies metabolic disturbances
   Abnormal phosphate can affect energy production.

5. Supports osteoporosis assessment
   Helps evaluate factors contributing to bone loss.

6. Useful in chronic disease monitoring
   Relevant in kidney and endocrine conditions.

7. Guides nutritional assessment
   Low levels may indicate malnutrition or malabsorption.

8. Supports clinical decision-making
   Helps guide further investigations and management.

Step-by-step – how we offer Phosphate testing

Clinic-based testing (UK-wide)

• Choose your nearest UK clinic

• Attend your appointment

• A qualified clinician or phlebotomist collects your blood sample

• Sample is sent to the laboratory for analysis

At-home or hotel testing (+£60)

• A qualified phlebotomist visits your home or hotel

• Blood sample collected in a comfortable, familiar setting

• No clinic visit or travel required

Both services are available UK-wide.

Your Phosphate results explained

Low phosphate levels (hypophosphataemia)

Low phosphate levels can impair energy production and bone mineralisation. This may result from poor dietary intake, vitamin D deficiency, hormonal disorders, or excessive losses through the kidneys or gastrointestinal tract.

Symptoms may include muscle weakness, fatigue, bone pain, and increased fracture risk.

UK reference range:

• Low: <0.80 mmol/L

Normal phosphate levels

Normal phosphate levels indicate balanced mineral metabolism and effective kidney and hormonal regulation. This supports healthy bone structure and cellular energy processes.

Results should be interpreted alongside calcium, vitamin D, and PTH levels.

UK reference range:

• Normal: 0.80–1.50 mmol/L

High phosphate levels (hyperphosphataemia)

High phosphate levels are most commonly associated with reduced kidney function, where phosphate excretion is impaired. Elevated levels can contribute to vascular calcification and bone disorders.

High phosphate may also occur with excessive supplementation or cell breakdown.

UK reference range:

• High: >1.50 mmol/L