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Updated: Aug 11, 2026

Estimation of Urinary Nanocrystals in Humans using Calcium Fluorophore Labeling and Nanoparticle Tracking Analysis
Published on: February 9, 2021
First reported stevia-containing human urinary calculi
Sara L Best1,2, John R Asplin2, Natalia Gromadzka2
1Department of Urology, University of Wisconsin, School of Medicine and Public Health, Madison, WI, USA.
Abstract:
While most kidney stones are made of typical substances like calcium oxalate, patients with uncommon metabolic disorders or exposures/ingestions can crystallize rare materials in their urinary tracts, leading to unusual stone compositions. Six stones in 5 individuals were evaluated when their composition did not match known lithogenic substances. We report the first ever identified human urinary calculi composed of steviol, a metabolite of the no-calorie sweetener, stevia.
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