Order Phosphorus (Phosphate) Blood Test from JustLabs for $5 ($23 all-in for a single-test order: $5 + one $18 lab & physician order fee per order). Price includes lab processing at Quest Diagnostics. No insurance required.
Phosphate is a mineral that works with calcium to build bones and teeth and helps make energy. Its blood level is controlled by the kidneys, vitamin D and parathyroid hormone, so an abnormal result is read alongside calcium and kidney tests.
Most of the phosphate in your body is stored in bone, bound to calcium. The rest circulates in the blood, where it acts as an electrolyte and helps with energy production and nerve and muscle function. Phosphorus comes from foods such as dairy, meat, poultry, eggs, beans, nuts and seeds.
Your body keeps blood phosphate within a narrow range through three controls: the kidneys, which excrete the extra; vitamin D, which helps absorb it; and parathyroid hormone (PTH), which balances it against calcium. When calcium goes up, phosphate tends to go down, and the reverse. That is why Quest notes that phosphate on its own has limited diagnostic value and should be read with calcium.
Phosphorus is not part of the Comprehensive Metabolic Panel (CMP) or the Basic Metabolic Panel (BMP). On JustLabs it is included in the Renal Function Panel, which also measures calcium, albumin and kidney markers. Ordering phosphorus on its own makes sense when you already have recent calcium and kidney results, need to re-check one abnormal phosphate value, or are monitoring phosphate as your clinician advised, for example with chronic kidney disease.
Mildly abnormal phosphate often causes no symptoms. A clinician interprets it with calcium, PTH, vitamin D and kidney function.
Price
$5
All-in
$23
incl. $18 lab & physician fee
Results
1-3 business days
Fasting
Not Required
What's Measured
What This Test Measures
This test measures inorganic phosphate in your blood serum, reported as phosphorus. Quest notes that phosphate should be correlated with serum calcium: high phosphate with low calcium suggests hypoparathyroidism or kidney disease; low phosphate with high calcium suggests hyperparathyroidism or sarcoidosis; low phosphate and low calcium suggest malabsorption, vitamin D deficiency or renal tubular acidosis; and high phosphate with normal or high calcium suggests milk-alkali syndrome or excess vitamin D.
Who Should Consider This Test
People with chronic kidney disease, or whose clinician is monitoring kidney function, who need phosphate followed over time; people with an abnormal calcium result being evaluated for a parathyroid or vitamin D problem; people re-checking a previous abnormal phosphate; and people with conditions that can disturb phosphate, such as malnutrition, malabsorption or poorly controlled diabetes, as their clinician advises.
Health Insights
Conditions Screened
Related Symptoms
When to Get Tested
Any time of day; Quest does not require fasting for this test. If your clinician wants results compared with earlier fasting samples, follow their instructions so the readings are comparable. Because phosphate is interpreted with calcium, it is most useful when calcium is measured on the same day.
No fasting needed. How to prepare for your blood test →
Understanding Your Results
A result within the lab's reference range is reassuring; Quest's directory lists 2.5-4.5 mg/dL for adults aged 21-64 and 2.1-4.3 mg/dL over 64, with higher ranges for children because their bones are growing. A high phosphate (hyperphosphatemia) is linked to later-stage chronic kidney disease, low parathyroid hormone (hypoparathyroidism), acidosis, excess vitamin D, and long-term use of phosphate laxatives, enemas or steroids. A low phosphate (hypophosphatemia) can come from overactive parathyroid glands (hyperparathyroidism), vitamin D deficiency, poor intake or absorption, alcohol use disorder, or antacids and diuretics; mildly low levels are often not a health problem, but severely low levels need urgent care. Results are interpreted with calcium, PTH, vitamin D and kidney tests. JustLabs results are informational; review them with a clinician.
What to Expect
After placing your order, we send it straight to Quest Diagnostics — there is no consent form to sign and no partner email to wait for. Your requisition is usually ready to download from your dashboard within about an hour, and you can book your blood draw at any Quest Diagnostics location.
The blood draw typically takes just a few minutes. Results are usually available within 1-3 business days and will appear in your secure JustLabs dashboard.
Our results include reference ranges and easy-to-understand indicators showing whether your values are within normal limits.
How much does the Phosphorus test cost?
The Phosphorus test costs $5 at JustLabs — $23 all-in, since the $18 lab & physician order fee is charged once per order, however many tests you add. The price is fixed before your blood draw; no insurance or doctor visit needed.
| Option | Price | Order all-in | Notes |
|---|---|---|---|
| Phosphorus at JustLabsDrawn at Quest Diagnostics | $5 | $23 | Includes the one $18 fee, charged once per order |
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Frequently Asked Questions
Hospital cash price: $120–$200
$5
+ $18 order fee · $23 all-inOne $18 fee per order covers your Quest blood draw and the independent physician order, however many tests you add.
- Results in 1-3 business days
- No fasting required
- Physician order included
No insurance needed · HSA/FSA eligible
- Physician-ordered
- CLIA-certified Quest lab
- Drawn at Quest Diagnostics
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