Phosphate in Urine
How It Feels
There is no pain while collecting a 24-hour urine sample.
There is no chance for problems while collecting a 24-hour urine
The phosphate urine test measures the amount of
phosphate in a sample of urine collected over 24 hours
(24-hour urine test). Phosphate is a charged particle (ion) that contains the
The normal values listed here—called a reference range—are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what's normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.
Results are usually
available in 1 to 2 days.
Phosphate in urine
grams (g) per 24-hour urine sample
millimoles (mmol) per day
| Calcium- and phosphate-restricted diet:
Less than 1.0 g per 24-hour urine sample
Less than 32 mmol per day
Many conditions can change phosphate levels. Your doctor will talk
with you about any abnormal results that may be related to your symptoms and
High urine phosphate levels may be caused by:
Low urine phosphate levels may be caused by:
- An underactive parathyroid gland (hypoparathyroidism).
- Kidney or liver diseases.
- Severe malnutrition.
What Affects the Test
Reasons you may not be able to have the test or why the results may
not be helpful include:
- Taking certain medicines, such as
diltiazem (such as Cardizem), aspirin,
- Taking a lot of
- Not collecting all of your urine within the 24-hour
What To Think About
- Phosphate may also be measured in the blood.
For more information, see the topic
Phosphate in Blood.
- Results of a test to
measure phosphate in urine are seldom useful on their own. They should always
be interpreted along with the results of other tests.
- The loss of
too much phosphate into the urine may cause conditions that damage the bones,
rickets or osteomalacia.
Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis: Saunders.
Other Works Consulted
Primary Medical Reviewer
||E. Gregory Thompson, MD - Internal Medicine
Specialist Medical Reviewer
||Alan C. Dalkin, MD - Endocrinology
||March 18, 2013