October 2026 English edition · Evidence reviewed through October 3, 2026 · David Shusterman, MD
Appendix O: Supplements, Vitamins, and Wellness Products
Supplements are often marketed as harmless additions to health. For a stone former, they are chemical exposures that can alter urinary calcium, oxalate, citrate, uric acid, pH, sodium, volume, or kidney function. The correct question is not whether a product is “natural.” It is whether the dose, formulation, indication, and metabolic effect make sense for this patient.
Vitamin C
High-dose vitamin C can be metabolized to oxalate and may increase urinary oxalate in susceptible patients. The risk depends on dose, kidney function, diet, and baseline urine chemistry. Food sources of vitamin C are not equivalent to concentrated high-dose supplements. Recurrent calcium oxalate stone formers should review large supplemental doses with their clinician.
Vitamin D
Vitamin D is important for bone health and should not be treated as forbidden. In some patients, supplementation can increase calcium absorption and urinary calcium, particularly at high doses or when combined with calcium supplements. The decision should consider serum levels, bone disease, parathyroid status, urine calcium, and the reason for treatment.
Calcium Supplements
Normal dietary calcium is generally protective for calcium oxalate stone formers because it binds oxalate in the intestine. Supplemental calcium may still be necessary for osteoporosis, pregnancy, malabsorption, or other indications. Timing with meals may help bind dietary oxalate. Dose, formulation, and total calcium intake should be individualized rather than stopped reflexively.
Magnesium
Magnesium can bind oxalate and plays roles in metabolism, but routine supplementation has not replaced established prevention strategies. Some formulations cause diarrhea, which can worsen dehydration and alter stone risk. Kidney impairment increases the risk of magnesium accumulation.
potassium citrate and Alkali Products
Prescription potassium citrate can raise urinary citrate and pH and is useful for selected metabolic patterns. Over-the-counter citrate powders, gummies, and alkalinizing products vary in actual alkali content, sodium load, sugar, and quality. Raising urine pH indiscriminately can be counterproductive for some calcium phosphate stone formers. Potassium can be dangerous in advanced kidney disease or with certain medications.
Creatine
Creatine is widely used for training and muscle performance. Current evidence does not establish that standard creatine dosing directly causes stones in healthy users, but supplements can complicate interpretation of serum creatinine, and training-related dehydration can increase stone risk. Product purity and combined pre-workout ingredients matter.
Protein Powders and Collagen
The relevant variables are total protein intake, source, sodium, sugar, additives, fluid balance, and the patient’s urine chemistry. Whey, plant, and collagen products are not automatically safe or dangerous. Very high protein intake can increase acid and purine burden in some patients. Collagen is rich in hydroxyproline, which can contribute to endogenous oxalate production; heavy use deserves review in recurrent calcium oxalate stone formers.
Electrolyte Drinks
Electrolyte products range from useful rehydration formulas to high-sodium flavored beverages. A person exercising for hours in heat may have different needs from someone walking for thirty minutes indoors. Read the sodium, sugar, potassium, and serving size. “Hydration” on the label does not guarantee a stone-smart formulation.
Multivitamins
A standard multivitamin may be reasonable when there is a nutritional indication, but stacking multiple products can create unexpectedly high totals of vitamin C, vitamin D, calcium, or other compounds. Review the combined daily exposure rather than each bottle separately.
Turmeric, Greens Powders, and Concentrated Plant Products
Some concentrated plant powders may contain meaningful oxalate loads even when marketed as anti-inflammatory or detoxifying. Spinach-based greens powders, beet powders, nut concentrates, and certain herbal blends can deliver far more of a compound than a normal serving of food. Whole-food benefits cannot always be extrapolated to concentrated powders.
Pre-Workout and Energy Products
Pre-workout formulas may combine caffeine, stimulants, sodium, creatine, amino acids, vitamins, and proprietary blends. They can reduce appetite, increase sweating, disturb sleep, and encourage exercise without adequate hydration. Energy drinks may add sugar or high caffeine loads. The stone risk often comes from the entire behavior pattern rather than one ingredient.
“Stone Breaker” Herbs
Products marketed as chanca piedra, stone breaker, kidney cleanse, or urinary detox should not be assumed to dissolve an obstructing stone. Product composition, dose, contamination, interactions, and clinical evidence vary. They can delay evaluation of infection or obstruction. No supplement replaces imaging, urine culture, kidney-function assessment, or a composition-based prevention plan.
Weight-Loss Products and GLP-1 Therapy
Rapid weight loss, reduced intake, nausea, vomiting, and dehydration can concentrate urine. GLP-1 medicines do not inherently create stones, but gastrointestinal side effects and reduced fluid intake can alter risk. Patients should protect hydration and nutrition and report persistent vomiting. Unregulated weight-loss supplements may contain stimulants, diuretics, or undeclared ingredients.
A Supplement Review Worksheet
For every product, record the brand, full ingredient list, dose per serving, actual daily servings, reason for use, prescriber if any, and start date. Then ask whether it affects fluid balance, sodium, calcium, oxalate, uric acid, urine pH, kidney function, bleeding, or medication interactions. Bring the bottles or photographs to the visit. “I take vitamins” is not enough information for a metabolic review.
The goal is not to eliminate every supplement. It is to replace marketing-based use with indication-based use.