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Are Supplements Bad for Your Kidneys? Stones, Creatine, Risky Herbs and Warning Signs

Yes, a few supplements can harm the kidneys. Vitamin C pills of 1,000 mg or more a day went with extra kidney stones in men (grade C), calcium with vitamin D slightly raised stone risk (grade B), and aristolochic acid herbs caused kidney failure. Creatine raises creatinine, a kidney blood test, without lowering kidney function in trials (grade B). With stage 4 or 5 kidney disease or dialysis, ask your nephrology team before any supplement.

Published How we grade evidenceEditorial policy

The short version

  • Vitamin C pills of 1,000 mg or more a day: a 19% higher kidney stone risk in men, not women. Grade C (Ferraro 2016).
  • Calcium with vitamin D slightly raised stone risk in pooled trials; calcium alone showed no clear rise. Grade B (Kahwati 2018).
  • Creatine raises creatinine, a kidney blood test, but measured kidney filtering did not change. Grade B (de Souza Almeida 2026).
  • Magnesium and potassium can build up to dangerous levels when kidneys work poorly. Grade C (Wakai 2019; Gritter 2022).
  • Aristolochic acid, in some traditional herbal remedies, has caused kidney failure and urinary tract cancer. Grade C (Luciano 2015).
SupplementWhat happenedGrade
Vitamin C, 1,000 mg+ a dayMore stones in menC
Calcium with vitamin DSlightly more stonesB
Vitamin DHigh blood calcium, not more stonesB
CreatineCreatinine up, filtering unchangedB
Magnesium, potassiumBuild-up with weak kidneysC
Licorice rootHigher blood pressure, lower potassiumB
Aristolochic acidKidney failure, cancerC

Can supplements cause kidney damage?

Yes: some raise stone risk, a few injure the kidney directly, and others build up when the kidneys can't clear them. The 2024 KDIGO kidney guideline tells clinicians to review and limit over-the-counter, dietary and herbal remedies that may harm people with chronic kidney disease (CKD), naming creatine, high-dose vitamin C and aristolochic acid (KDIGO 2024). The National Kidney Foundation lists creatine and licorice root as high risk with kidney disease (NKF).

With stage 4 or 5 CKD, or on dialysis, ask your nephrology team before any supplement. Stage 4 means an eGFR (estimated glomerular filtration rate, a blood-test filtering score) of 15 to 29; stage 5 is below 15 (KDIGO 2024).

Is creatine bad for your kidneys?

Grade B: in trials, creatine didn't lower measured kidney function, but it raises creatinine, the blood test behind eGFR. Pooling 19 randomized trials, creatine raised blood creatinine by 0.13 mg/dL with no difference in eGFR (8 trials); longer trials are needed (Tsiaras 2026). In a second review of trials in healthy adults and people with CKD, eGFR estimated from creatinine read 10.75 mL/min lower, while filtering measured directly with a tracer did not differ (de Souza Almeida 2026). In 18 young men taking about 10 g a day for 3 months, cystatin C, a marker not made from creatine, showed no harm (Gualano 2008).

Grade D for harm, from case reports involving several products. A 24-year-old weightlifter on creatine and other supplements developed kidney inflammation (Thorsteinsdottir 2006); 4 bodybuilders injecting steroids and taking 15 g of creatine a day plus protein products had damaged kidney tubules (Almukhtar 2015). Our creatine page shows a D for kidney function, from one study; we give B because two pooled analyses of randomized trials agree.

Does vitamin C cause kidney stones?

Grade C, in men taking high doses. In US cohorts of 40,536 men and 156,735 women, tracked for medians of 11.3 to 11.7 years, men whose vitamin C pills reached at least 1,000 mg daily had a 19% higher stone risk (hazard ratio 1.19); women showed no link, and vitamin C from food showed none in either sex (Ferraro 2016). A pooled analysis of 4 studies agreed: men only (Jiang 2019).

Grade B that the pills raise urine oxalate, a stone risk factor: a 2026 review of 9 studies found a rise in people with and without past stones, 6.45 mg a day more than placebo where there was one (Farkouh 2026). Grade D for kidney damage: oxalate crystals injured the kidneys of a man with past bowel surgery taking 2 g a day (Lin 2019).

Upper limit for adults: 2,000 mg of vitamin C a day, because more can cause diarrhea and stomach upset; take more only with blood tests or your clinician's advice (NIH ODS; check your stack). See our vitamin C page.

Do calcium supplements cause kidney stones?

Grade B for a small rise when taken with vitamin D. Among 36,282 women past menopause, daily calcium carbonate (1,000 mg) plus vitamin D3 (400 IU) for about 7 years raised kidney stones 17% against placebo (hazard ratio 1.17) (Jackson 2006). Pooling 3 trials (39,213 people), the combination added 0.33 percentage points to stone risk; calcium alone showed no difference in 3 small trials (1,259 people) (Kahwati 2018).

Grade C that calcium from food goes with fewer stones. US nurses with the most dietary calcium had 35% fewer stones, while supplement users had 20% more; two-thirds took pills without a meal or with low-oxalate meals, and the authors suggest that calcium eaten with food binds oxalate in the gut (Curhan 1997). So favor food calcium and take any pill with a meal; we found no trial of the timing.

Upper limit for adults: 2,500 mg of calcium a day (ages 19 to 50) and 2,000 mg (51 and older), because more can cause high blood calcium and kidney stones; take more only with blood tests or your clinician's advice (NIH ODS; check your stack). See our calcium page.

Can vitamin D cause kidney stones?

Grade B: vitamin D raised blood and urine calcium; pooled trials showed no more stones. Pooling long-term trials, vitamin D made high blood calcium (relative risk 1.54, 37 studies) and high urine calcium (1.64, 14 studies) more likely; stones, reported in 9 trials, were not more common (Malihi 2016). Over 3 years in 373 healthy adults aged 55 to 70, mild high blood calcium affected 9% on 10,000 IU a day, 3% on 4,000 IU and none on 400 IU (Billington 2020).

Upper limit for adults: 4,000 IU (100 mcg) of vitamin D a day, because more can cause high blood calcium; take more only with blood tests or your clinician's advice (NIH ODS; check your stack). See our vitamin D page.

Is magnesium safe for your kidneys?

Grade C: magnesium builds up when the kidneys clear it poorly; with healthy kidneys, too much mainly causes diarrhea. Among 320 hospital patients in Japan prescribed magnesium oxide (a laxative and antacid), high blood magnesium showed up in 23%, with about three times the odds at an eGFR of 55.4 or below (Wakai 2019). In older adults with very low kidney clearance taking 900 mg or more of magnesium oxide a day, the rate was 53.1% (Ishii 2023). Regular magnesium laxatives caused fatal high magnesium in a 53-year-old woman with normal kidneys (Bokhari 2018).

Upper limit for adults: 350 mg of magnesium a day from supplements, because more can cause diarrhea; take more only with blood tests or your clinician's advice (NIH ODS; check your stack). If you use blood pressure medicine, read can I take magnesium with blood pressure medicine? and our magnesium page.

What else builds up when kidneys fail?

  • Potassium. Grade C. In 191 people with CKD stage 3b to 4, potassium chloride (40 mmol a day for 2 weeks) raised blood potassium by 0.4 mmol/L, and 21 (11%) developed high potassium (hyperkalemia) (Gritter 2022). Potassium has no upper limit, but extra is dangerous with kidney disease or drugs such as ACE inhibitors (NIH ODS). See our potassium page.
  • Phosphorus. Seaweed and algae products, green powders and seed-based supplements are often high in it (NKF).
  • Vitamin A. Grade D. It builds up in kidney failure even below usual toxic amounts: a woman with CKD taking 7,000 IU a day for about 10 years developed high blood calcium, which settled after she stopped (Hammoud 2014). Upper limit for adults: 10,000 IU (3,000 mcg) of preformed vitamin A a day, because more can cause birth defects and liver damage; take more only with blood tests or your clinician's advice (NIH ODS).

Which herbs can damage the kidneys?

  • Aristolochic acid. Grade C. It comes from Aristolochia plants (birthwort, wild ginger) used in some traditional remedies (NKF). Weight-loss pills in which one herb was swapped for Aristolochia by mistake caused kidney scarring; of 39 users with failed kidneys who had them removed, 18 (46%) had urinary tract cancer (Nortier 2000). The disease moves quickly to kidney failure (Luciano 2015). The FDA calls aristolochic acid "a potent carcinogen and nephrotoxin" and detains products containing it at import (FDA Import Alert 54-10).
  • Licorice root. Grade B. Pooling 18 studies (337 people) of products with at least 100 mg of glycyrrhizic acid a day, systolic blood pressure rose 5.45 mm Hg and blood potassium fell 0.33 mmol/L from starting levels (Penninkilampi 2017). See our licorice page.
  • Turmeric. Grade C. In 11 healthy adults, supplement doses of turmeric raised urine oxalate more than cinnamon or no spice (Tang 2008); a 69-year-old man on long-term turmeric, with diarrhea from antibiotics, developed oxalate kidney damage (Washington 2024). See our curcumin page.
  • Red yeast rice. Grade D. A cholesterol supplement containing it (beni-koji) injured kidney tubules in 2 biopsied patients; one was left with CKD (Habuka 2024).
  • NSAID painkillers such as ibuprofen are medicines, but KDIGO ties regular over-the-counter use to kidney failure (KDIGO 2024).

What is the best supplement for kidney health?

We found no trial of a supplement keeping healthy kidneys healthy; in CKD, no randomized trial shows a vitamin supplement improving kidney, heart or patient-centered outcomes (Wang 2024). For diabetes, see supplements and kidney health in diabetes. For stones:

  • Water. Grade C. After a first calcium stone, 12 of 99 people told to drink more water had another within 5 years, against 27 of 100 without advice (Borghi 1996); Cochrane rated this low certainty (Bao 2020). In a 2026 trial of 1,658 people, a program that raised urine output did not cut stone events (19% against 20%) (Desai 2026).
  • Citrate, a prescription medicine. Grade B. Citrate salts, mainly potassium citrate, cut new stones (7 trials, 324 people: relative risk 0.26), but more people quit over stomach side effects (Phillips 2015).
  • Lemon juice. Grade C, no clear difference. Over 2 years in people with calcium oxalate stones, 21 of 100 on fresh lemon juice and 32 of 103 controls had a new stone (not significant; Ruggenenti 2022).
  • Cranberry is studied for urinary tract infections, not kidney function (Williams 2023).
  • Protein powder. Higher-protein diets did not change kidney filtering in healthy adults (28 studies, 1,358 people). Grade B (Devries 2018). With CKD, ask your kidney team; see our whey protein page.

What we'd skip

Safety and interactions

  • Potassium with ACE inhibitors, ARBs or spironolactone can push blood levels too high (NIH ODS). Ask your prescriber or pharmacist.
  • Licorice with blood pressure drugs or water pills: licorice alone raised blood pressure and lowered potassium (Penninkilampi 2017); no interaction studies were found. Ask your prescriber.
  • Vitamin D with calcium pills may add to the risk of high blood calcium (NIH ODS).
  • Several products at once: check your stack against the upper limits.

When to see a doctor

  • Emergency care: severe one-sided back or belly pain with fever or vomiting, or little or no urine.
  • Same day: blood in your urine; or muscle weakness, an irregular heartbeat or vomiting after starting potassium, a salt substitute or a new blood pressure drug (Te Dorsthorst 2019).
  • Soon: new swelling of your legs, ankles or face, foamy urine, or a creatinine rise on a routine test.
  • Before any supplement: stage 4 or 5 CKD, dialysis or a kidney transplant.

Don't stop a prescribed medicine on your own; ask the prescriber or pharmacist. If you are pregnant, breastfeeding or under 18, ask a clinician.

FAQ

Is creatine bad for your kidneys? In randomized trials, creatine raised the blood test creatinine but did not lower directly measured kidney filtering (grade B). With kidney disease, ask your nephrology team first.

Does vitamin C cause kidney stones? In US cohorts, men whose vitamin C pills reached at least 1,000 mg daily had a 19% higher stone risk (grade C); women, and vitamin C from food, showed no link.

Is magnesium safe for your kidneys? With healthy kidneys, too much from supplements mainly causes diarrhea (adult upper limit 350 mg a day). With weak kidneys it can build up dangerously (grade C), so ask first.

Is turmeric safe for your kidneys? In 11 healthy adults, turmeric raised urine oxalate, a stone risk factor (grade C), and one man on it long term developed oxalate kidney damage. With past stones or kidney disease, ask first.

Sources

  1. Ferraro PM, et al. Total, Dietary, and Supplemental Vitamin C Intake and Risk of Incident Kidney Stones. Am J Kidney Dis. 2016. PubMed 26463139 · doi:10.1053/j.ajkd.2015.09.005
  2. Kahwati LC, et al. Vitamin D, Calcium, or Combined Supplementation for the Primary Prevention of Fractures in Community-Dwelling Adults: Evidence Report and Systematic Review for the US Preventive Services Task Force. JAMA. 2018. PubMed 29677308 · doi:10.1001/jama.2017.21640
  3. de Souza Almeida A, et al. Impact of creatine supplementation on kidney health: a systematic review and meta-analysis. Int Urol Nephrol. 2026. PubMed 42507286 · doi:10.1007/s11255-026-05287-x
  4. Wakai E, et al. Risk factors for the development of hypermagnesemia in patients prescribed magnesium oxide: a retrospective cohort study. J Pharm Health Care Sci. 2019. PubMed 30805197 · doi:10.1186/s40780-019-0133-7
  5. Gritter M, et al. Effects of Short-Term Potassium Chloride Supplementation in Patients with CKD. J Am Soc Nephrol. 2022. PubMed 35609996 · doi:10.1681/ASN.2022020147
  6. Luciano RL, et al. Aristolochic acid nephropathy: epidemiology, clinical presentation, and treatment. Drug Saf. 2015. PubMed 25446374 · doi:10.1007/s40264-014-0244-x
  7. Tsiaras A, et al. The Effect of Creatine Supplementation on Kidney Function: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. J Ren Nutr. 2026. PubMed 42035842 · doi:10.1053/j.jrn.2026.04.010
  8. Gualano B, et al. Effects of creatine supplementation on renal function: a randomized, double-blind, placebo-controlled clinical trial. Eur J Appl Physiol. 2008. PubMed 18188581 · doi:10.1007/s00421-007-0669-3
  9. Thorsteinsdottir B, et al. Acute renal failure in a young weight lifter taking multiple food supplements, including creatine monohydrate. J Ren Nutr. 2006. PubMed 17046619 · doi:10.1053/j.jrn.2006.04.025
  10. Almukhtar SE, et al. Acute kidney injury associated with androgenic steroids and nutritional supplements in bodybuilders(†). Clin Kidney J. 2015. PubMed 26251708 · doi:10.1093/ckj/sfv032
  11. Jiang K, et al. Ascorbic Acid Supplements and Kidney Stones Incidence Among Men and Women: A systematic review and meta-analysis. Urol J. 2019. PubMed 30178451 · doi:10.22037/uj.v0i0.4275
  12. Farkouh A, et al. The Effect of Vitamin C Supplements on Urinary Stone Risk: A Systematic Review and Meta-Analysis. J Endourol. 2026. PubMed 42535313 · doi:10.1177/08927790261471733
  13. Lin WV, et al. Ascorbic acid-induced oxalate nephropathy: a case report and discussion of pathologic mechanisms. CEN Case Rep. 2019. PubMed 30276648 · doi:10.1007/s13730-018-0366-6
  14. Jackson RD, et al. Calcium plus vitamin D supplementation and the risk of fractures. N Engl J Med. 2006. PubMed 16481635 · doi:10.1056/NEJMoa055218
  15. Curhan GC, et al. Comparison of dietary calcium with supplemental calcium and other nutrients as factors affecting the risk for kidney stones in women. Ann Intern Med. 1997. PubMed 9092314 · doi:10.7326/0003-4819-126-7-199704010-00001
  16. Malihi Z, et al. Hypercalcemia, hypercalciuria, and kidney stones in long-term studies of vitamin D supplementation: a systematic review and meta-analysis. Am J Clin Nutr. 2016. PubMed 27604776 · doi:10.3945/ajcn.116.134981
  17. Billington EO, et al. Safety of High-Dose Vitamin D Supplementation: Secondary Analysis of a Randomized Controlled Trial. J Clin Endocrinol Metab. 2020. PubMed 31746327 · doi:10.1210/clinem/dgz212
  18. Ishii H, et al. A case-control study showing low creatinine clearance and high magnesium intake as risk factors for hypermagnesemia in older individuals. Magnes Res. 2023. PubMed 37897255 · doi:10.1684/mrh.2023.0513
  19. Bokhari SR, et al. Fatal Hypermagnesemia Due to Laxative Use. Am J Med Sci. 2018. PubMed 29661354 · doi:10.1016/j.amjms.2017.08.013
  20. Hammoud D, et al. Hypercalcaemia secondary to hypervitaminosis a in a patient with chronic renal failure. West Indian Med J. 2014. PubMed 25303202 · doi:10.7727/wimj.2011.171
  21. Nortier JL, et al. Urothelial carcinoma associated with the use of a Chinese herb (Aristolochia fangchi). N Engl J Med. 2000. PubMed 10841870 · doi:10.1056/NEJM200006083422301
  22. Penninkilampi R, et al. The association between consistent licorice ingestion, hypertension and hypokalaemia: a systematic review and meta-analysis. J Hum Hypertens. 2017. PubMed 28660884 · doi:10.1038/jhh.2017.45
  23. Tang M, et al. Effect of cinnamon and turmeric on urinary oxalate excretion, plasma lipids, and plasma glucose in healthy subjects. Am J Clin Nutr. 2008. PubMed 18469248 · doi:10.1093/ajcn/87.5.1262
  24. Washington O, et al. Oxalate nephropathy and chronic turmeric supplementation: a case report. J Bras Nefrol. 2024. PubMed 38427579 · doi:10.1590/2175-8239-JBN-2023-0079en
  25. Habuka M, et al. Fanconi syndrome with acute proximal tubular injury induced by a dietary supplement containing beni-koji: a case series report. BMC Nephrol. 2024. PubMed 39639196 · doi:10.1186/s12882-024-03903-5
  26. Wang AY, et al. Vitamin Supplement Use in Patients With CKD: Worth the Pill Burden? Am J Kidney Dis. 2024. PubMed 37879527 · doi:10.1053/j.ajkd.2023.09.005
  27. Borghi L, et al. Urinary volume, water and recurrences in idiopathic calcium nephrolithiasis: a 5-year randomized prospective study. J Urol. 1996. PubMed 8583588
  28. Bao Y, et al. Water for preventing urinary stones. Cochrane Database Syst Rev. 2020. PubMed 32045491 · doi:10.1002/14651858.CD004292.pub4
  29. Desai AC, et al. Prevention of urinary stones with hydration: a randomised clinical trial of an adherence intervention. Lancet. 2026. PubMed 41864748 · doi:10.1016/S0140-6736(25)02637-6
  30. Phillips R, et al. Citrate salts for preventing and treating calcium containing kidney stones in adults. Cochrane Database Syst Rev. 2015. PubMed 26439475 · doi:10.1002/14651858.CD010057.pub2
  31. Ruggenenti P, et al. Fresh lemon juice supplementation for the prevention of recurrent stones in calcium oxalate nephrolithiasis: A pragmatic, prospective, randomised, open, blinded endpoint (PROBE) trial. EClinicalMedicine. 2022. PubMed 34977512 · doi:10.1016/j.eclinm.2021.101227
  32. Williams G, et al. Cranberries for preventing urinary tract infections. Cochrane Database Syst Rev. 2023. PubMed 37068952 · doi:10.1002/14651858.CD001321.pub6
  33. Devries MC, et al. Changes in Kidney Function Do Not Differ between Healthy Adults Consuming Higher- Compared with Lower- or Normal-Protein Diets: A Systematic Review and Meta-Analysis. J Nutr. 2018. PubMed 30383278 · doi:10.1093/jn/nxy197
  34. Te Dorsthorst RPM, et al. Review of case reports on hyperkalemia induced by dietary intake: not restricted to chronic kidney disease patients. Eur J Clin Nutr. 2019. PubMed 29588531 · doi:10.1038/s41430-018-0154-6