A patient seated in the chair before a blood draw
In person

Phosphate

A mineral for bones and energy, read with calcium, from one draw.

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  • 2,000+ lab locations. Find one near you
  • Nothing due at the lab. FSA / HSA accepted
  • Ordered by a licensed clinician

At a glance

Collection
Blood draw
A standard blood draw at the lab.
Preparation
None
Nothing to do ahead of time. Water is fine.
Results
1 to 2 days
Typical turnaround after your visit.
Where
2,000+ lab locations
Nationwide, with nothing due at the lab.

About this test

Phosphate is a mineral your body uses to build bones and teeth and to store and use energy in cells. On its own, phosphate says little, so it is read with calcium, since parathyroid hormone, vitamin D, and the kidneys shape both. It is usually a follow-up test. No fasting is needed.

For adults 18 and older. Test availability varies by lab location.

Who should take this test?

This test is for adults whose healthcare provider wants to follow phosphate with calcium, often for bone, kidney, or parathyroid questions, or after a past result.

Ask about this test

Not sure this is the right test?

AI-generated. For information only, not medical advice. Call 911 for an emergency.

What does this test measure?

Your result shows how much phosphate is in your blood, which can help a healthcare provider read it together with calcium for bone, kidney, and parathyroid questions.

Phosphate (phosphorus)
Phosphate is a mineral that works with calcium to build bones and teeth and helps cells store energy. Your kidneys and hormones help control the level. On its own it says little, so a healthcare provider reads it together with your calcium and kidney results.
Why it’s measured: Read with calcium and kidney results to check mineral balance.

How it works

  1. Step 1

    Order online

    Check out here. A licensed clinician in your state reviews your order and sends it to the lab.

  2. Step 2

    Visit a lab

    Bring a photo ID to any of 2,000+ lab locations. No fasting needed, and nothing is due at the lab.

  3. Step 3

    Get your results

    Results post to your account, usually in 1 to 2 days, each number next to the lab’s reference range.

Find a lab near you

Choose from 2,000+ lab locations nationwide. Your order works at any of them.

What your results tell you

Phosphate is reported as phosphorus in milligrams per deciliter (mg/dL) and compared with the lab’s reference range on your report.

  • Your number next to the lab’s reference range
  • Explained in plain language
  • A licensed clinician reviews your order and, if appropriate, orders the test.
  • A lab report you can download and share

Phosphate is read with calcium and kidney markers, so talk with a healthcare provider about your result in that context.

Clinical-grade testing, from the comfort of home.

From the lab to your report, every step of our process meets the gold standard in medical testing.

  • CLIA-certified labs

    Every lab we partner with is certified under the Clinical Laboratory Improvement Amendments, meeting both state and federal standards with regular independent inspections.

  • We protect your health data

    We protect your health data with encryption and do not sell it. Some results must be reported to public health authorities by law. See our Privacy Notice.

  • Rigorous quality assurance

    All partner labs run regular internal quality checks, participate in proficiency testing, and comply with federal and state lab regulations.

  • Clinician-reviewed reports

    Results are reviewed by an independent, licensed clinician.

Questions

Common questions.

Anything else, our care team answers by phone, text, or email.

Calcium and phosphate are controlled by the same hormones, mainly parathyroid hormone and vitamin D, along with the kidneys. On its own, phosphate is of limited value.

The combination of phosphate and calcium, whether they move together or in opposite directions, is what points a healthcare provider toward possible causes.

Phosphate levels can reflect the parathyroid glands, vitamin D status, kidney function, and how well the gut absorbs nutrients. Because so many systems are involved, a result outside the range is a starting point for a conversation with a healthcare provider, not an answer.

For this test, yes. Phosphorus in the body is mostly found as phosphate, and the lab reports it as phosphorus. The test does not measure bone density or tell you how much phosphorus you eat. A healthcare provider reads it with calcium and kidney markers.

Lab tests are informational and don’t diagnose conditions on their own. Available to adults 18 and older; test availability varies by lab location. A licensed clinician reviews your order and, if appropriate, orders the test. All testing is performed at CLIA-certified laboratories. Not for emergencies: if you think you may be having a medical emergency, call 911.