(UroToday.com) In the moderated poster session on medical management of stones, Dr. Daniel Jhang presented his research on the effects of vitamin C supplementation on urinary parameters critical for kidney stone formation. Vitamin C is one of the most commonly taken supplements and recently, the incidence of urolithiasis has increased. This study is in response to growing concerns about the increased frequency and complexity of kidney stones associated with higher vitamin C intake during the COVID-19 pandemic. Vitamin C is believed to contribute to stone formation via oxalate, a byproduct of vitamin C metabolism.

Dr. Jhang began by explaining his systematic review process using the PRISMA guidelines. Dr. Jhang and his team conducted a comprehensive literature search for relevant studies published between 1965 and February 2023. Only intervention studies that investigated the effects of vitamin C supplements on urinary parameters were included. These studies compared the results with baseline values ​​or a placebo group. The meta-analysis focused on calculating the mean difference (MD) in urinary oxalate, citrate, and calcium. From an initial pool of 808 studies, nine studies met the criteria for inclusion in the meta-analysis.


Systematic analysis and meta-analyses showed a significant increase in urinary oxalate levels after vitamin C supplementation. Compared to baseline, the mean difference was 9.72 mg/24h (p
Dr. Jhang concluded that vitamin C supplements significantly increase urinary oxalate excretion in both individuals with and without kidney stones. This increase in urinary oxalate levels could potentially contribute to kidney stone formation or worsen existing stone disease.

Presented by: Daniel Jhang, MD, Department of Urology, Loma Linda University Health, Loma Linda, CA

Written by: Renai Yoon, Researcher, Department of Urology, University of California Irvine, @renaiyoon on Twitter/X during the 2024 World Congress of Endourology and Urotechnology: August 12-16, 2024, Seoul, South Korea