Apple cider vinegar for prevention of urinary lithiasis (APUL): a randomized crossover trial.

PURPOSE: To evaluate the potential stone-preventative effects of apple cider vinegar (ACV) supplementation on 24-h urinary citrate, pH, and volume.

METHODS

We performed a randomized crossover trial testing ACV, coconut water, lemon water, and orange soda. Participants were non-stone formers randomized to two of the four beverages. Participants consumed one assigned beverage daily for one week, underwent a two-week washout period, and then consumed the second assigned beverage. Three 24-h urine collections were planned: one baseline collection prior to beverage consumption, one following completion of the first treatment week, and one following completion of the second week.

RESULTS

Twenty participants were enrolled. Eight were female. Six consumed ACV, six coconut water, eight lemon water, and six diet orange soda. ACV did not significantly change 24-h urinary parameters. 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. Effects on urine pH and volume were not significant in any treatment arms.

CONCLUSION

ACV did not significantly change 24-h urine parameters. Coconut water and lemon water increased urinary citrate. Further study is necessary to validate these findings in a larger cohort. Registered with ClinicalTrials.gov (NCT04073719, 8/28/2019).