Kidney Stones and Excess Vitamin C

Written By Antonino Ruscitto

Vitamin C Supplementation and Kidney Stone Risk

Taking high doses of vitamin C supplements—generally defined as 500 mg per day or more on a regular basis—has been associated with an increased risk of kidney stone formation in certain individuals, particularly calcium oxalate stones (Ferraro et al., 2013; Thomas et al., 2013). This risk appears to be elevated among individuals with a personal or family history of nephrolithiasis.

Vitamin C (ascorbic acid) is partially metabolized into oxalate, which is subsequently excreted in the urine. Elevated urinary oxalate levels can increase the likelihood of calcium oxalate crystal formation, the most common type of kidney stone (Ferraro et al., 2013).

Recommended Dietary Allowance (RDA) for Vitamin C

For individuals at risk of kidney stone formation, experts recommend not exceeding the Recommended Dietary Allowance (RDA) for vitamin C (National Institutes of Health [NIH], n.d.):

  • 75 mg per day for adult women

  • 90 mg per day for adult men

Vitamin C From Food Sources

Vitamin C is naturally abundant in many commonly consumed foods, making routine supplementation unnecessary for most individuals. Vitamin-C-rich foods include:

  • Broccoli

  • Cauliflower

  • Mangoes

  • Oranges

  • Strawberries

  • Kale

In many cases, a single serving of these foods can meet or exceed daily vitamin C requirements (NIH, n.d.). When dietary intake is combined with vitamin C supplements or vitamin-C-containing multivitamins, total intake may unintentionally exceed recommended levels, potentially increasing kidney stone risk in susceptible individuals (Ferraro et al., 2013; Thomas et al., 2013).

A Kidney-Conscious Multivitamin Approach

CERO® Multi is a zero-vitamin-C multivitamin formulated with kidney stone prevention in mind. Designed by physicians, it supports daily nutritional needs without contributing excess vitamin C, which may be problematic for individuals prone to stone formation. The formulation emphasizes a food-first nutritional philosophy, intended to complement—rather than replace—a healthy, whole-food diet.

When taken as directed (two capsules daily), alongside adequate hydration and appropriate dietary choices, CERO® Multi may be incorporated into a broader strategy aimed at reducing kidney stone risk while supporting overall wellness.

Key Points:

  • Excess Vitamin C intake has been shown to increase kidney stone risk

  • Kidney stone sufferers, especially, should monitor their daily vitamin C intake

References

Curhan, G. C. (2007). Epidemiology of stone disease. Urologic Clinics of North America, 34(3), 287–293. https://doi.org/10.1016/j.ucl.2007.04.003

Ferraro, P. M., Curhan, G. C., Gambaro, G., & Taylor, E. N. (2013). Total, dietary, and supplemental vitamin C intake and risk of incident kidney stones. JAMA Internal Medicine, 173(5), 386–388. https://doi.org/10.1001/jamainternmed.2013.2296

National Institutes of Health, Office of Dietary Supplements. (n.d.). Vitamin C fact sheet for health professionals. https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/

Thomas, L. D. K., Elinder, C. G., Tiselius, H. G., Wolk, A., & Åkesson, A. (2013). Ascorbic acid supplements and kidney stone incidence among men: A prospective study. JAMA Internal Medicine, 173(5), 386–388. https://doi.org/10.1001/jamainternmed.2013.2296

Antonino Ruscitto
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