Serum Fluoride Concentration (24-Hour Urine Collection)
This test measures the amount of fluoride in your urine over a 24-hour period to assess fluoride exposure or excretion.
["Understanding fluoride levels in your urine helps track how your body processes this mineral, which may be important for certain health evaluations."]
Key facts at a glance
- LOINC
- 63992-2
- Short code
- PHX_FLUORIDE_SUPP
- Synonyms
- Child vitamins W fluoride PhenX
- Category
- chemistry
- Sample
- serum
- Container
- Not applicable; data is collected via structured interview or questionnaire form.
- Units
- N/A
- Ref low
- 30
- Ref high
- 100
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–17 years
- Method
- phenx
- Specimen volume
- Not applicable; no biological specimen is collected for this PhenX assessment item.
- Stability
- Not applicable; no specimen is collected.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Your healthcare provider may order this test if you have symptoms or conditions related to fluoride exposure, such as dental fluorosis (excess fluoride in teeth), bone disorders, or if you work in environments with high fluoride exposure (e.g., certain industries). It can also be part of monitoring for people taking fluoride supplements or medications.
What to Expect Before the Test
You’ll need to collect all urine for a full 24-hour period in a special container. Start and end times are typically set by your provider. Drink plenty of fluids to help urine flow normally, but avoid excessive caffeine or diuretics unless instructed otherwise.
How the Test Is Done
The collected urine sample is sent to a lab for analysis. The lab measures fluoride concentration in your urine, which reflects how much fluoride your body is excreting over the day.
What the Results Mean
Results are usually reported as the total fluoride amount excreted in milligrams (mg) over 24 hours. Interpretation depends on clinical context, such as your medical history, symptoms, or exposure risks.
Reference range
NCBI: Vitamin D 30-100 ng/mL (sufficient)N/A
No special preparation required. This is a caregiver-reported questionnaire item completed during clinical or research assessment. Caregivers should report current fluoride supplementation status at the time of assessment.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
None
Frequently asked questions
How long does a 24-hour urine collection take?
Can I drink water during the urine collection?
What should I do if I miss any urine during the collection?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy