How Kidney Stones Form
Simplifying Complex Process
First, just a little bit of biology. You have two kidneys located on each side of your lower back, just above your waistline. Their main job is to filter your blood of toxins and excess substances and turn that waste into urine (National Institute of Diabetes and Digestive and Kidney Diseases [NIDDK], 2023). Inside each kidney are millions of tiny filtering units called nephrons, which are responsible for this process (Guyton & Hall, 2021).
Once urine is formed, it passes from the kidneys through tubes called ureters to the bladder, where it is stored. When enough urine collects, the bladder empties through another tube called the urethra. The kidneys, nephrons, ureters, bladder, and urethra together make up the urinary tract. Still with me?
Good! There are a lot of small—but very important—tubes involved in this system. Together, your two kidneys produce about 1.5 to 3 liters of urine per day, filtering more than 180–200 liters of blood plasma every 24 hours (Guyton & Hall, 2021; NIDDK, 2023).
Urine contains water and various dissolved waste products, including minerals and salts. As urine moves through the urinary tract, it becomes too concentrated, to often due to inadequate fluid intake. When urine becomes too concentrated—often due to inadequate fluid intake—these dissolved substances can begin to form tiny crystals within the narrow passageways of the urinary tract (Coe et al., 2005).
Starting to see the problem?
Back to the crystals. Other substances in the urine can attach to these microscopic crystals, allowing them to grow larger over time. If they are not flushed out, they can continue to enlarge, eventually forming kidney stones (Khan et al., 2016; Coe et al., 2005).
If stones do not move, they may attach to the lining of the urinary tract or become too large to pass. Stones that obstruct urine flow can cause a backup of urine, leading to increased pressure in the kidney and significant pain (Pearle et al., 2014).
Even stones that are not stuck can be extremely painful as they move through the ureter on their way out of the body. If this is you, your physician has likely instructed you on pain management and advised you to drink plenty of fluids. Increased fluid intake leads to increased urine production, which can help flush smaller stones out of the urinary tract (Pearle et al., 2014).
If conservative measures fail, medical intervention—such as medication, shock wave therapy, or surgical removal—may be required to safely remove the stone (Türk et al., 2023).
While kidney stones can be painful and disruptive, many are preventable. Prevention focuses on keeping urine dilute and reducing the conditions that allow crystals to form and grow.
Hydration is the foundation of prevention. Adequate fluid intake helps dilute urine and lowers the concentration of stone-forming minerals. Clinical guidelines commonly recommend producing at least 2 to 2.5 liters of urine per day, which may require higher fluid intake depending on activity level, climate, and individual needs (Türk et al., 2023). Water is generally the preferred fluid.
Dietary patterns significantly influence urine chemistry. Diets high in sodium and excessive animal protein can increase urinary calcium excretion, raising stone risk (Curhan et al., 1997). Diets rich in fruits and vegetables may increase urinary citrate, a natural inhibitor of stone formation (Taylor & Curhan, 2008). Adequate dietary calcium from food—rather than high-dose supplements—can help bind oxalate in the gut, limiting how much reaches the kidneys (Heaney, 2008).
Supplement choices deserve careful consideration. High-dose vitamin C supplementation has been shown to increase urinary oxalate excretion, which may elevate the risk of calcium oxalate stone formation in susceptible individuals (Thomas et al., 2013; Ferraro et al., 2016). For individuals with a history of kidney stones, avoiding excessive vitamin C intake from supplements may be prudent.
Magnesium plays a supportive role in urinary balance. Magnesium can bind oxalate in the gut and urine, reducing calcium oxalate supersaturation and crystal formation (Massey, 2005). Lower urinary magnesium levels have been associated with increased stone risk, while adequate intake may contribute to a more protective urinary environment (Kohri et al., 1988).
CERO Multi® was developed with these considerations in mind—designed to complement, not replace, hydration, nutrition, and healthy lifestyle choices. When used thoughtfully alongside adequate fluid intake and dietary guidance, kidney-aware supplementation may support healthier urine chemistry without introducing excessive stone-promoting nutrients.
Ultimately, kidney stone prevention is not about a single solution, but about a consistent, whole-body approach—supporting the kidneys every day so they can continue doing what they do best.
Key Points:
Waste filtered by your kidneys becomes crystals, crystals become stones
Stones enlarge and cause pain; not good
Supplements should be chosen carefully. High-dose vitamin C supplements may increase stone risk in susceptible individuals, while nutrients like magnesium may help reduce crystal formation when consumed appropriately.
References
Coe, F. L., Evan, A., & Worcester, E. (2005). Kidney stone disease. Journal of Clinical Investigation, 115(10), 2598–2608.
Curhan, G. C., Willett, W. C., Rimm, E. B., & Stampfer, M. J. (1997). Family history and risk of kidney stones. Journal of the American Society of Nephrology, 8(10), 1568–1573.
Ferraro, P. M., Curhan, G. C., Gambaro, G., & Taylor, E. N. (2016). Total, dietary, and supplemental vitamin C intake and risk of incident kidney stones. American Journal of Kidney Diseases, 67(3), 400–407.
Guyton, A. C., & Hall, J. E. (2021). Textbook of medical physiology (14th ed.). Elsevier.
Heaney, R. P. (2008). Calcium intake and disease prevention. Arq Bras Endocrinol Metabol, 52(7), 1091–1096.
Khan, S. R., Pearle, M. S., Robertson, W. G., Gambaro, G., Canales, B. K., Doizi, S., Traxer, O., & Tiselius, H. G. (2016). Kidney stones. Nature Reviews Disease Primers, 2, 16008.
Kohri, K., Garside, J., Blacklock, N. J., & Beckett, A. H. (1988). The role of magnesium in calcium oxalate urolithiasis. British Journal of Urology, 61(2), 107–115.
Massey, L. K. (2005). Dietary influences on urinary oxalate and risk of kidney stones. Frontiers in Bioscience, 10, 2133–2142.
National Institute of Diabetes and Digestive and Kidney Diseases. (2023). Your kidneys and how they work. U.S. Department of Health and Human Services.
Pearle, M. S., Goldfarb, D. S., Assimos, D. G., Curhan, G., Denu-Ciocca, C. J., Matlaga, B. R., & Preminger, G. M. (2014). Medical management of kidney stones. Journal of Urology, 192(2), 316–324.
Taylor, E. N., & Curhan, G. C. (2008). Diet and fluid prescription in stone disease. Kidney International, 73(10), 1178–1184.
Thomas, L. D., Elinder, C. G., Tiselius, H. G., Wolk, A., & Akesson, A. (2013). Ascorbic acid supplements and kidney stone incidence among men. JAMA Internal Medicine, 173(5), 386–388.
Türk, C., Neisius, A., Petrik, A., Seitz, C., Skolarikos, A., & Thomas, K. (2023). EAU guidelines on urolithiasis. European Association of Urology.
