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Citric acid urine test
Definition
This is a test to measure the amount of citric acid in urine.
Alternative Names
Urine - citric acid test
How the Test is Performed
A 24-hour urine sample is needed. The health care provider will instruct you, if necessary, to discontinue drugs that may interfere with the test.
- On day 1, urinate into the toilet when you get up in the morning.
- Afterwards, collect all urine in a special container for the next 24 hours.
- On day 2, urinate into the container when you get up in the morning.
- Cap the container. Keep it in the refrigerator or a cool place during the collection period. Label the container with your name, the date, the time of completion, and return it as instructed.
For an infant, thoroughly wash the area around the urethra. Open a urine collection bag (a plastic bag with an adhesive paper on one end), and place it on the infant. For males, the entire penis can be placed in the bag and the adhesive attached to the skin. For females, the bag is placed over the labia. Diaper as usual over the secured bag.
This procedure may take a couple of attempts -- lively infants can displace the bag, causing the specimen to be absorbed by the diaper. The infant should be checked frequently and the bag changed after the infant has urinated into the bag. The urine is drained into the container for transport to the laboratory.
Deliver it to the laboratory or your health care provider as soon as possible upon completion. A laboratory specialist will determine how much citric acid is found in the urine sample.
How to Prepare for the Test
No special preparation is necessary for this test. However, the results are influenced by your diet, and this test is typically performed while you are eating regularly. Ask your health care provider for more information.
How the Test Will Feel
The test involves only normal urination, and there is no discomfort.
Why the Test is Performed
The test is used to diagnose renal tubular acidosis and evaluate kidney stone disease.
Normal Results
The normal range is 320 - 1240 milligrams per 24 hours.
The examples above are common measurements for results of these tests. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.
What Abnormal Results Mean
Low levels of citric acid may indicate possible renal tubular acidosis and a tendency to form calcium kidney stones.
The following may decrease urine citric acid levels:
- Acidosis
- Chronic kidney failure
- Diabetes
- Hypoparathyroidism
- Excessive muscle activity
- Medicines called angiotensin converting enzymes inhibitors (ACE inhibitors)
The following may increase urine citric acid levels:
- A high carbohydrate diet
- Estrogen therapy
- Vitamin D
Risks
There are no risks.
References
Landry DW, Basari H. Approach to the patient with renal disease.In: Goldman L, Schafer AI, eds.Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 116.
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Herbert Y. Lin, MD, PHD, Nephrologist, Massachusetts General Hospital; Associate Professor of Medicine, Harvard Medical School. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
