Kidney stones are painful and surprisingly often linked to low citric acid in urine. When citric acid levels fall, urine becomes more prone to forming calcium oxalate or calcium phosphate crystals, raising the risk of kidney stone disease. This link, called hypocitraturia, frequently appears in people with poor diet, dehydration, certain medications, or renal tubular acidosis.

Low urinary citrate excretion weakens the body’s built‑in defense by allowing calcium salts to stick and grow into stones. Without enough citrate, kidney stones can form more easily and more often.

This article explains the causes, symptoms, testing, and treatment options for low citric acid in urine to help you prevent future kidney stones.

Citric acid plays a key role in preventing kidney stone formation by neutralizing free calcium in urine. It also helps retain the proper urinary pH so crystals don’t get a foothold.

Citric acid, found naturally in fruits like lemons and limes, helps the body manage energy and supports healthy kidney function. In urine, citrate binds calcium ions, which reduces the likelihood of calcium oxalate or calcium phosphate crystals forming. That binding action inhibits crystal aggregation and improves uric acid solubility, helping fend off stone formation. When levels drop, calcium‑based stones become easier to form.

Normal urinary citrate levels help shield against stone disease by keeping calcium and acid in balance. Hypocitraturia (low citric acid in urine) means there isn't enough citrate to stop crystal growth, and the urine pH may shift. Those changes increase risks for calcium oxalate renal stones and calcium phosphate stones. Keeping optimal urinary citrate levels and urine pH reduces the chance of kidney stones developing.

A drop in urinary citrate can stem from what you eat, chronic health issues, hydration habits, or certain medications. Each plays a part in affecting your kidney stone risk.

A diet lacking in fruits and vegetables, especially citrus like lemon and lime juice, lowers citrate levels in urine. Heavy intake of salt or animal protein can further reduce citrate concentration and hamper calcium metabolism. Without enough citrate excretion, calcium kidney stones become more likely.

Health conditions such as chronic renal insufficiency, renal tubular acidosis, or other metabolic disorders interfere with citrate filtration. These alter urine pH and reduce citrate output. Conditions like metabolic acidosis are known to heighten risks for calcium stone formation and uric acid stones. Evaluating renal stone disease often includes checking for these underlying issues and may require diagnosing renal tubular acidosis.

Insufficient fluid intake makes urine more concentrated, lowering citric acid levels and boosting the risk of kidney stone formation. High levels of urinary oxalate, calcium, or uric acid in less diluted urine favor crystal growth. Staying hydrated supports citrate excretion, lowers calcium output, and helps maintain proper urine pH.

Some drugs, like carbonic anhydrase inhibitors, diuretics, or ACE inhibitors, can reduce citrate excretion and raise urinary stone risk. These medicines may also change urine pH in a way that encourages calcium phosphate or uric acid stone creation. If you’re on these treatments, discuss your risk of renal calculi and low urinary citrate with your doctor.

Low citric acid in urine doesn’t usually cause obvious symptoms, but it increases the chance of renal stone disease. Many people only find out they have low urine citrate after having a kidney stone.

Low urinary citrate levels usually don’t cause noticeable symptoms at first. However, when citrate excretion is too low, it can lead to the formation of kidney stones, which often bring painful and disruptive symptoms. Signs that may point to low citric acid in urine include:

• Sharp pain in the back, side, or lower abdomen: Often a sign that a kidney stone is moving through the urinary tract.

• Blood in the urine (hematuria): Stones can irritate or damage the lining of the urinary tract.

• Painful or difficult urination: Caused by stones blocking or irritating the urinary flow.

• Frequent urge to urinate: Especially if a stone is near the bladder.

• Nausea or vomiting: May occur with more severe kidney stone formation or if pain is intense.

When citrate concentration is too low, calcium binds easily to oxalate or phosphate and forms stones. Calcium oxalate crystals aggregate and grow into full kidney stones. Recurrence is especially common in people who are calcium stone formers or those with chronically reduced citrate excretion.

Low citric acid in urine increases the risk of more than just kidney stones. Without proper treatment, repeated stone formation can lead to serious long-term issues related to kidney function and urinary health. People with chronic stone disease or low citrate levels may face additional complications, such as:

• Urinary tract infections (UTIs): Stones can block urine flow and create a breeding ground for bacteria.

• Kidney scarring: Ongoing kidney stone formation may damage kidney tissues over time.

• Renal failure: In severe or untreated cases, repeated stone formation can lead to lasting kidney damage or renal failure.

• Chronic discomfort: Frequent stones may cause long-term pain and reduced quality of life.

• Higher recurrence risk: People with persistent low urinary citrate are more likely to become recurrent stone formers.

To confirm low urine citrate levels, doctors rely on targeted urine and blood tests. These tests pinpoint the cause and guide treatment.

A 24‑hour urine test measures urinary citrate excretion along with calcium, oxalate, uric acid, urine pH, and other stone risk markers. Low filtered citrate points toward hypocitraturia. Citric acid test measures help doctors decide if potassium citrate therapy or dietary changes are needed.

Blood tests help check for metabolic issues like renal tubular acidosis or metabolic acidosis that impact citrate excretion. These conditions also alter calcium metabolism and urine chemistry, increasing the risk of kidney stone disease.

Managing low citric acid in urine starts with lifestyle changes and may include medication. The goal is to raise urinary citrate levels and reduce the risk of kidney stone formation.

Eating more citrus fruits and juices raises citric acid levels naturally. A balanced diet with fruits and vegetables also supports a healthy urine pH. Limiting sodium and animal protein can help reduce calcium excretion and improve citrate concentration.

Doctors may prescribe potassium citrate supplementation to boost urinary citrate. This treatment helps inhibit calcium salts from forming stones. Potassium citrate therapy is especially useful for people with a history of calcium kidney stones or uric acid stones. In some cases, sodium potassium citrate may be an option.

Drinking enough water helps dilute urinary oxalate, uric acid, and calcium, making stone formation less likely. Good hydration also supports healthy urinary citrate levels. This balance helps maintain proper urine pH and reduces the risk of kidney stones.

Under medical guidance, medications affecting citrate excretion (such as diuretics or carbonic anhydrase inhibitors) can be adjusted. In select cases, sodium bicarbonate or potassium chloride may correct metabolic acidosis and improve citrate excretion.

Preventing low urine citrate starts with small but consistent changes in daily habits. These steps help reduce the chance of developing stones in the first place.

Simple changes to your daily habits can help raise urinary citrate levels and reduce the risk of kidney stone formation. These steps support better calcium metabolism, improve urine pH, and help prevent recurring stone disease:

• Add citrus fruits and juices like lemons, limes, and oranges to boost natural citric acid levels.

• Drink plenty of water throughout the day to support citrate excretion and keep urine diluted.

• Limit salt and animal protein, as excess sodium can raise calcium excretion, increasing the chance of forming stones.

• Eat potassium-rich foods such as bananas, avocados, and leafy greens, or take supplements if advised by a doctor.

• Avoid high-oxalate foods like spinach and beets if you're prone to calcium oxalate stones, and focus on a normal diet that supports a balanced urinary pH.

For people at risk of recurrent stone formation, regular testing is key. A 24-hour urine test helps track urinary citrate levels, citrate excretion, and other risk markers. Repeat testing also helps evaluate renal stone disease and adjust treatment if needed.

Doctors may follow research-backed methods, such as those cited by Dr. Khashayar Sakhaee, to guide therapy for patients with low urine citrate or renal tubular acidosis.

Click here to learn more about Alerna's Uric Acid Supplements to support your kidney health and overall well-being!

Low citric acid in urine is a major risk factor for kidney stone disease, especially in people with high levels of calcium or uric acid in their urine. This condition, known as hypocitraturia, is often caused by a poor diet, dehydration, certain medications, or underlying issues like renal tubular acidosis.

A 24-hour urine test can measure urinary citrate levels to confirm the diagnosis and guide treatment. Increasing citrus intake, staying well-hydrated, taking potassium citrate, and adjusting medications under medical guidance can help raise citrate levels and lower the risk of kidney stone formation.

Addressing low urine citrate early can prevent complications and support long-term kidney health.

The information provided in this article is for educational and informational purposes only and should not be considered a substitute for professional medical advice, diagnosis, or treatment. Please consult with your healthcare provider before starting any new dietary supplement, especially if you are pregnant, nursing, have a medical condition, or are taking other medications. Never disregard professional medical advice or delay in seeking it because of something you have read in this article.

1. Bao, Y., Tu, X., & Wei, Q. (2020). Water for preventing urinary stones. The Cochrane database of systematic reviews, 2(2), CD004292. https://doi.org/10.1002/14651858.CD004292.pub4

2. Haleblian, G. E., Leitao, V. A., Pierre, S. A., Robinson, M. R., Albala, D. M., Ribeiro, A. A., & Preminger, G. M. (2008). Assessment of citrate concentrations in citrus fruit-based juices and beverages: implications for management of hypocitraturic nephrolithiasis. Journal of endourology, 22(6), 1359–1366. https://doi.org/10.1089/end.2008.0069

3. Leslie, S. W., & Bashir, K. (2024, August 1). Hypocitraturia and renal calculi. In StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK564392/

4. Sakhaee, K. (n.d.). Khashayar Sakhaee, M.D. UT Southwestern Medical Center. https://utswmed.org/doctors/khashayar-sakhaee/

5. Wiegand, A., Fischer, G., Seeger, H., Fuster, D., Dhayat, N., Bonny, O., Ernandez, T., Kim, M. J., Wagner, C. A., & Mohebbi, N. (2019). Impact of potassium citrate on urinary risk profile, glucose and lipid metabolism of kidney stone formers in Switzerland. Clinical kidney journal, 13(6), 1037–1048. https://doi.org/10.1093/ckj/sfz098