Does apple cider vinegar help with kidney stones?

There is no good evidence that it does. The only randomized trial of apple cider vinegar for stone prevention gave it daily for a week to adults who had never had stones, and urinary citrate, pH and volume did not change. That trial stopped early, and only 6 people took the vinegar, which is too few to detect a modest effect. A different product, Chinese mature grain vinegar, cut stone recurrence in one small pilot. The treatment with strong evidence is potassium citrate.

Unsettled. This is unsettled rather than disproven, for two reasons we can name. The apple cider vinegar trial was tiny and short, in healthy volunteers, and measured urine markers rather than stones. The vinegar that did reduce stones was a different vinegar, tested once, in one center.

What the trials found

Apple cider vinegar itself

A randomized crossover trial compared four drinks, apple cider vinegar, coconut water, lemon water and diet orange soda, each for one week, in adults who had not had kidney stones. Twenty people enrolled, 10 finished both periods, and 6 completed the apple cider vinegar arm. Recruitment stopped before reaching its goal because of staff changes. Apple cider vinegar did not significantly change 24-hour urinary citrate, pH or volume. In the same trial lemon water raised urinary citrate by 167.7 mg a day (95% CI 16 to 319) and coconut water by 273.8 mg a day (95% CI 67.9 to 480). Citrate in urine helps stop calcium crystals forming, so it is used as a marker, and none of these people had stones to prevent.

A different vinegar, with a stone outcome

In a Chinese pilot randomized trial of 79 stone-free people who had previously had calcium oxalate stones, mature grain vinegar was compared with water over 6 to 12 months or more. The relative risk of a stone coming back was 0.31 (95% CI 0.12 to 0.69) in the vinegar group. Urinary citrate improved in 72% of the vinegar group against 19% of controls. The dose was 1 tsp (5 mL) three times a day, about 12.5 mEq of acetate daily. This was a single center with 7 withdrawals, and the control was water, which does not taste like vinegar. The acetic acid content of apple cider vinegar differs by brand, so that dose does not translate to a bottle off the shelf.

The same research group compared 61 adults drinking more than 1 tbsp (15 mL) of vinegar a day with 61 matched non-drinkers. The vinegar drinkers had more citrate and less calcium in their urine. That is an association, and vinegar drinkers may eat differently. In rats given a chemical that causes calcium oxalate crystals, daily vinegar raised urinary citrate and lowered urinary calcium. Laboratory data like this suggest a mechanism and show nothing about people.

What the reviews say about vinegar

We found no systematic review or meta-analysis of vinegar and kidney stones. A 2025 systematic review of 26 dietary intervention studies in people with stones mentions vinegar only in a list of foods tested, with no pooled estimate.

What does prevent stones

Established. An umbrella review of 9 meta-analyses, 88 trials and 27,286 people found potassium citrate cut the risk of stone recurrence by 79%, on high-certainty evidence. That is a relative figure, and the review as quoted gives no absolute rates. Potassium citrate works through the same urinary citrate that vinegar is claimed to raise.

A 2026 systematic review of 31 studies in people with recurrent stones lists more water, a diet with normal to high calcium and low protein and salt, thiazides, alkali treatment and allopurinol as options that may reduce recurrence, on low strength of evidence. Vinegar is not on the list. The review excluded studies with fewer than 30 people per group, so the vinegar pilot could not have qualified.

Who should be careful

Not for everyone. Vinegar is an acid, and its harms come from that. No adverse effects were reported in the week-long apple cider vinegar trial, which with 6 people on vinegar is too small to catch uncommon harms. In a crossover trial of 16 healthy young adults, 0.88 oz (25 g) of vinegar with breakfast raised nausea ratings, most with the less palatable drink. A 2020 case report described severe metabolic acidosis in an obese patient combining a ketogenic diet, large amounts of vinegar and metformin, made worse by acute kidney injury.

That last case matters most for people whose kidney function is reduced. If your kidney function is reduced or you take metformin, large amounts of vinegar are a question for whoever treats you. The 2026 review found minor side effects may be more common with lemon juice, the acidic home remedy most often compared with vinegar, on low strength of evidence. We found no evidence on vinegar for stones in pregnancy or in children.

What expert bodies say

We looked for a position from the US National Institute of Diabetes and Digestive and Kidney Diseases, the American Urological Association and the European Association of Urology. None of them mentions vinegar for kidney stones, for or against.

How we searched

What would change this answer

• A blinded randomized trial of apple cider vinegar in people who form calcium oxalate stones, with stones coming back as the outcome. We found none.
• A larger replication of the Chinese mature vinegar pilot. The apple cider vinegar trial on the US registry, NCT04073719, has an unknown status and no posted results.

More on this food: apple cider vinegar. Related question: calcium and kidney stones.

Sources

1. ev-acvks-01 · Randomized controlled trial(s) · randomized crossover trial · n = 20
   ACV did not significantly change 24-h urinary parameters.
   
   Who: adult non-stone formers in a randomized crossover trial of four beverages; 6 completed the ACV arm
   Effect: ACV: no significant change in 24-h urinary citrate, pH or volume
   Certainty: Very small, one week per beverage, surrogate urine markers, healthy volunteers.
   Int Urol Nephrol, 2026 · checked 2026-10-07 · we read the abstract
2. ev-acvks-02 · Randomized controlled trial(s) · randomized crossover trial · n = 20
   Coconut water (+ 273.8 mg/24 h, 95% CI 67.9-480 mg/24 h) and lemon water (+ 167.7 mg/24 h, 95% CI 16-319 mg/24 h) were associated with increased urinary citrate.
   
   Who: adult non-stone formers; 8 drank lemon water, 6 coconut water
   Effect: urinary citrate: coconut water +273.8 mg/24 h (95% CI 67.9 to 480); lemon water +167.7 mg/24 h (16 to 319)
   Certainty: Small arms; citrate is a surrogate marker, not stone events.
   Int Urol Nephrol, 2026 · checked 2026-10-07 · we read the abstract
3. ev-acvks-03 · Randomized controlled trial(s) · randomized crossover trial · n = 20
   Patient accrual was stopped prior to reaching recruitment goals due to changes in department personnel and loss of research staff.
   
   Who: 20 enrolled, 15 completed period 1, 10 completed period 2
   Effect: effective sample size 25 treatment periods; recruitment goal not reached
   Certainty: Gap statement from the trial's own results section.
   Int Urol Nephrol, 2026 · checked 2026-10-07 · we read the fulltext
4. ev-acvks-04 · Randomized controlled trial(s) · randomized crossover trial · n = 20
   No adverse effects were reported.
   
   Who: adult non-stone formers drinking ACV, coconut water, lemon water or diet orange soda daily for one week
   Effect: no adverse effects reported
   Certainty: One week only, 6 people on ACV; too small to detect uncommon harms.
   Int Urol Nephrol, 2026 · checked 2026-10-07 · we read the fulltext
5. ev-acvks-05 · Randomized controlled trial(s) · randomized controlled pilot trial · n = 79
   The relative risk of a recurrence among the patients in the vinegar group, as compared with the patients in control groups, was 0.31 (95% confidence interval, 0.12 to 0.69; P = .0098).
   
   Who: stone-free patients with a history of calcium oxalate nephrolithiasis, followed 6 to 12 months or more
   Effect: relative risk of recurrence 0.31 (95% CI 0.12 to 0.69); urinary citrate improved in 72% vs 19%
   Certainty: Mature Chinese grain vinegar, not apple cider vinegar; single center, 7 withdrawals, control was water, not blinded to taste.
   EBioMedicine, 2019, 45:231-250 (Zhu et al., Dietary vinegar prevents kidney stone recurrence via epigenetic regulations) · checked 2026-10-07 · we read the fulltext
6. ev-acvks-06 · Randomized controlled trial(s) · randomized controlled pilot trial · n = 79
   Participants administered 5 ml mature vinegar (Ninghuafu®) three times a day (containing 12.5 mEq. acetate per day) or control as liquid of the same type in identical bottles.
   
   Who: calcium oxalate stone formers in the vinegar arm
   Effect: 15 mL/day mature vinegar (12.5 mEq acetate per day) versus identical-looking control liquid
   Certainty: Dose applies to Ninghuafu mature vinegar; acetic acid content of apple cider vinegar differs by brand.
   EBioMedicine, 2019, 45:231-250 (Zhu et al., Dietary vinegar prevents kidney stone recurrence via epigenetic regulations) · checked 2026-10-07 · we read the fulltext
7. ev-acvks-07 · Observational data · propensity-matched cross-sectional comparison · n = 122
   Taken together, these analyses indicate that dietary vinegar is correlated with urine chemistry, particularly citrate and calcium excretion that might suppress kidney stone formation in adults.
   
   Who: adults without nephrolithiasis from a six-city Chinese screening survey; 61 drinking more than 1 tbsp (15 mL) vinegar a day vs 61 matched non-drinkers
   Effect: higher urinary citrate and pH, lower urinary calcium and CaOx crystallization index in daily vinegar drinkers
   Certainty: Association; vinegar drinkers may differ in diet; no stone outcome.
   EBioMedicine, 2019, 45:231-250 (Zhu et al., Dietary vinegar prevents kidney stone recurrence via epigenetic regulations) · checked 2026-10-07 · we read the fulltext
8. ev-acvks-08 · Laboratory or animal data · animal experiment · n = 6 to 8 rats per group
   However, administration of vinegar significantly increased urine citrate excretion (Fig. 1b), a well-known inhibitor of CaOx crystallization [28,29], and decreased urine calcium excretion which is a component and a strong promoter of CaOx crystal formation (Fig. 1c) [30,31].
   
   Who: 8-week-old Sprague-Dawley rats with ethylene glycol-induced calcium oxalate crystals, vinegar 2 mL/kg for 4 weeks
   Effect: higher urine citrate, lower urine calcium, no change in urinary oxalate
   Certainty: Animal model; mechanism proposed via acetate and renal citrate transporter NADC1.
   EBioMedicine, 2019, 45:231-250 (Zhu et al., Dietary vinegar prevents kidney stone recurrence via epigenetic regulations) · checked 2026-10-07 · we read the fulltext
9. ev-acvks-09 · Meta-analysis or systematic review · umbrella review of meta-analyses of RCTs with GRADE · n = 27286
   The use of potassium citrate was able to prevent the risk of nephrolithiasis recurrence of 79%, supported by a high level of evidence.
   
   Who: patients in RCTs of non-surgical kidney stone prevention and treatment
   Effect: potassium citrate: recurrence risk -79% (high GRADE); thiazides -66% in 571 recurrent stone formers
   Certainty: Context: the proven citrate route, which vinegar is claimed to mimic.
   Minerva Urol Nephrol, 2025 · checked 2026-10-07 · we read the abstract
10. ev-acvks-10 · Meta-analysis or systematic review · systematic review of RCTs and nonrandomised intervention studies · n = 31 studies
    For adults with calcium oxalate or phosphate stones, increased water intake; a diet with normal to high calcium, low protein, and low sodium; thiazides; alkali treatment; and allopurinol may reduce stone recurrence (low SOE).
    
    Who: nonpregnant adults and children with recurrent nephrolithiasis; 26 RCTs and 5 nonrandomised studies
    Effect: increased water, normal to high calcium, low protein, low sodium, thiazides, alkali, allopurinol may reduce recurrence (low strength of evidence)
    Certainty: Excluded studies with fewer than 30 participants per group, so the 79-person vinegar pilot could not qualify.
    Ann Intern Med, 2026 · checked 2026-10-07 · we read the abstract
11. ev-acvks-11 · Meta-analysis or systematic review · systematic review of RCTs and nonrandomised intervention studies · n = 31 studies
    There may be increased minor adverse events with lemon juice but no increased harm due to serious adverse events with thiazides and allopurinol (low SOE).
    
    Who: adults in trials of stone prevention
    Effect: possible increase in minor adverse events with lemon juice (low strength of evidence)
    Certainty: Low strength of evidence.
    Ann Intern Med, 2026 · checked 2026-10-07 · we read the abstract
12. ev-acvks-12 · Meta-analysis or systematic review · systematic review of intervention studies · n = 26 articles
    In addition, foods such as lemon, orange, melon, lime, cranberry, apple juices, milk, vinegar, black seed, green bean extract, probiotics and synbiotic were also explored, which promoted significant changes in serum and urinary parameters related to UL.
    
    Who: people with urolithiasis in dietary intervention studies up to July 2025
    Effect: vinegar listed among foods that changed serum or urinary parameters; no stone outcome pooled
    Certainty: Narrative synthesis; vinegar evidence appears to rest on single small studies.
    Nutr Res Rev, 2025 · checked 2026-10-07 · we read the abstract
13. ev-acvks-13 · Randomized controlled trial(s) · randomized crossover acute feeding study · n = 16
    In Study 1, ingestion of vinegar significantly reduced quantitative and subjective measures of appetite, which were accompanied by significantly higher nausea ratings, with unpalatable treatment having the greatest effect.
    
    Who: healthy, young, normal weight unrestrained eaters, Study 1
    Effect: significantly higher nausea ratings with vinegar; largest with the unpalatable drink
    Certainty: Single-meal study; vinegar dose 25 g.
    Int J Obes (Lond), 2014 · checked 2026-10-07 · we read the abstract
14. ev-acvks-14 · Laboratory or animal data · case report · n = 1
    The use of dietary acetic acid is usually well tolerated; however, in this case, the large quantities and presence of acute renal injury may have worsened the acidosis.
    
    Who: one obese patient on ketogenic diet, vinegar and metformin
    Effect: severe acidosis requiring hospitalization
    Certainty: Single case with several causes; relevant to people with reduced kidney function.
    Case Rep Nephrol, 2020 · checked 2026-10-07 · we read the abstract