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BioMed Research International
Volume 2018, Article ID 3061742, 5 pages
Research Article

Coconut Water: An Unexpected Source of Urinary Citrate

1Department of Urology, University of California, Irvine, USA
2Litholink Corporation, Laboratory Corporation of America® Holdings, USA
3Department of Medicine University of California, Irvine, USA

Correspondence should be addressed to Roshan M. Patel;

Received 3 May 2018; Revised 18 September 2018; Accepted 26 September 2018; Published 1 November 2018

Guest Editor: Ephrem Olweny

Copyright © 2018 Roshan M. Patel et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Purpose. Coconut water has long been touted for its medicinal qualities including natural hydration. We sought to determine whether its consumption would induce changes to urinary lithogenic factors beyond changes in urine volume. Materials and Methods. After Institutional Review Board approval, volunteers with no prior history of nephrolithiasis were recruited. Each participant was randomized initially to either the coconut water or the water phase of the study. Participants kept meticulous food and fluid intake logs during the first phase of the study and were asked to replicate that diet for the second phase. For each phase the participant consumed 2L of either Taste of Nirvana® pure coconut water or tap water daily for four days. Participants were not restricted to consume additional fluid of their choice during their assigned study phase. During days 3 and 4 of each phase the participant collected a 24-hour urine specimen. Coconut water citrate and malate content were measured and were used along with the beverage pH to calculate the total alkali content of the coconut water. Supersaturation levels were calculated using Equil2. Nonparametric paired analysis using the Wilcoxon test was performed for statistical analysis. Results. There were 4 adult male and 4 adult female participants. Each individual’s 24-hour urine collection had a creatinine excretion within 20% of the mean for each subject’s four samples corroborating that all samples were collected properly. The two samples from each phase for each individual were averaged. The coconut water itself was also analyzed and it was calculated to have a total alkali content of 13.8 mEq/L. Consumption of coconut water significantly increased urinary citrate (29%, p=0.02), urinary potassium (130%, p=0.01), and urinary chloride (37%, p=0.03), without affecting urine pH (p=0.16) or volume beyond that of tap water (p=1.00). Conclusions. Coconut water consumption increases urinary potassium, chloride, and citrate in nonstone forming individuals.