In this 5-minute breakdown I review the most common supplements for UTIs.
The take-home points
✓ Cranberry — the one with real evidence. Aim for 36 mg of A-type PAC twice a day (or 72 mg once). Pick a powder or extract that lists its PAC content. Best for women with recurrent, uncomplicated UTIs.
✗ D-mannose — skip it. It looked promising, but the large 2024 SWEET trial found it no better than placebo.
✗ Vitamin C — the data isn’t strong. One small pregnancy trial, and no proof it prevents UTIs otherwise. Keep it under 1,000 mg/day (higher doses raise kidney-stone risk in men).
One caveat: none of these reliably help frail elderly people, catheter users, or men.
Want every study and the full reasoning? Read the full write-up: https://www.paretolife.com/p/cranberry-d-mannose-and-vitamin-c-for-utis-what-the-2024-to-2025-evidence-actually-says
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The full deep-dive on this topic: https://www.paretolife.com/p/cranberry-d-mannose-and-vitamin-c-for-utis-what-the-2024-to-2025-evidence-actually-says
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References
Williams et al., Cochrane 2023 · Kontiokari et al., BMJ 2001 · Stothers, Can J Urol 2002 · Maki et al., Am J Clin Nutr 2016 · Barbosa-Cesnik et al., Clin Infect Dis 2011 · Kranjčec et al., World J Urol 2014 · Hayward et al. (SWEET), JAMA Intern Med 2024 · Ochoa-Brust et al., Acta Obstet Gynecol Scand 2007 · Ackerman et al. (AUA/CUA/SUFU), J Urol 2025 · Ferraro & Curhan, Am J Kidney Dis 2016.