Supplements are being marketed for everything from boosting your immunity to enhancing productivity. But don't be fooled—natural doesn't always mean safe, especially for your kidneys. HaVy Ngo-Hamilton, PharmD, a BuzzRx clinical consultant, says it's "a common myth" to think that supplements can't cause any kidney damage just because they're available over the counter.
"It's not feasible to try to memorize or keep a list of supplements that you should watch out for," she says, suggesting the list is long. Instead, "the best thing to do to avoid unpleasant or even dangerous drug interactions is to ask your doctor or pharmacist before you start taking any supplements."
If you experience symptoms of kidney damage, it's important to share a list of every medication and supplement you're taking with your doctor. They can help you determine whether one of your supplements is to blame, or if there is another underlying cause. That said, since knowledge is essential in this department, here’s a list of common supplements that can damage your kidneys, according to doctors.
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1 | Turmeric
Microgen / ShutterstockTurmeric, also known as curcumin, is often used for its anti-inflammatory properties. However, Angela Dori, PharmD, a pharmaceutical patient consultant and medical content creator, says that if you have a history of kidney problems including kidney stones, you should avoid taking high doses of turmeric.
"Turmeric contains oxalate, which can bind to minerals and increase the risk of kidney stones," she shared in a TikTok post.
2 | Vitamin C
PeopleImages / iStockDori also says it's important to avoid "mega-doses" of vitamin C. Though the daily recommended amount is 75 mg for women and 90 mg for men, according to the Mayo Clinic, many people take supplements in 1,000 mg doses that far surpass the body's needs.
As Dori explains, "excess vitamin C is excreted as oxalate, which can form kidney stones."
A 2023 study also linked vitamin C supplements to renal failure. "The high, toxic dose of vitamin C has been proven to cause hyperoxaluria and complications like acute kidney injury," the study authors wrote.
In fact, a recent case report published earlier this year details a 67-year‑old man with chronic kidney disease who suffered acute kidney injury after taking 3 grams of vitamin C per day, ultimately showing calcium oxalate crystal deposits in his kidneys.
The Mayo Clinic states that, in most cases, you can get adequate levels of vitamin C without supplementation through your diet alone. Do this by eating whole foods, like chopped red peppers, brussels sprouts, cabbage, broccoli, or spinach.
3 | Vitamin D
Food Impressions / ShutterstockTaking vitamin D can also have adverse effects on the kidneys. "Vitamin D supplements can interact with aluminum-containing phosphate binders often used in chronic kidney disease patients to reduce the phosphate levels in the blood," Ngo-Hamilton explains. "Therefore, vitamin D can result in harmful levels of aluminum in people with chronic kidney disease."
However, Ngo-Hamilton notes that this doesn't necessarily mean that people with kidney disease should not take vitamin D supplements. "As long as your doctor is aware, they can recommend a safe dosage for you, in addition to periodic blood work to monitor blood levels of different minerals," she says.
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4 | Calcium
iStockDori recommends avoiding high doses of calcium, especially if you take it with vitamin C. "Calcium is excreted through urine, and most kidney stones are composed of calcium and oxalate," she says.
However, she notes that, under your doctor's supervision, taking magnesium and vitamin B6 can help offset the effects of calcium supplements.
5 | Potassium
eternalcreative / iStockPotassium supplements are available over the counter, but Harvard Health Publishing says you should not take a daily potassium supplement unless your doctor has prescribed it. It can cause kidney damage and hyperkalemia, the condition of having unsafe high serum or plasma potassium levels.
"People with chronic kidney disease, including those on dialysis, must watch their potassium intake to prevent potassium accumulation in the blood," explains Ngo-Hamilton. "Hyperkalemia causes nausea, vomiting, muscle cramps, weakness, and tiredness. Severe hyperkalemia can cause heart rhythm problems and even death. Unknowingly taking herbal supplements that contain potassium can further increase the risk of hyperkalemia."
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6 | Vitamin A
3 | Vitamin AGalina Zhigalova/ShutterstockWhile low doses support vision and immunity, high doses of vitamin A from supplements are fat-soluble and can accumulate, causing hypervitaminosis A.
This increases kidney strain and risks of liver damage, as shown in a 2023 health alert linking excessive vitamin A to nephrotoxicity.
7 | Creatine
Research Reveals the No. 1 Supplement to Take After a Bad Night's SleepiStockMany gym-goers use creatine to help build muscle and increase performance, but the supplement can put excessive stress on your kidneys—especially if you have kidney disease, experts at My Kidney Disease Team say.
"It can raise blood levels of creatinine (a waste product with a similar name), which can make it look like kidney function is worse, even if it’s not causing damage," they write. "People with kidney disease should avoid creatine unless a doctor says it’s safe."
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8 | Licorice Root
Consuming licorice root, particularly in large amounts or over a prolonged period, can potentially lead to kidney damage, research shows.
According to a 2019 study, "Licorice, today chiefly utilized as a flavoring additive in tea, tobacco, and candy, is one of the oldest used herbs for medicinal purposes and consists of up to 300 active compounds."
However, its main compound, glycyrrhizin, can potentially increase blood pressure, thus impacting your kidney health. The National Center for Complementary and Integrative Care (NCCIC)Trusted Source suggests that anyone who has hypertension, heart disease, or kidney disease, as well as people who are pregnant or nursing, should not use licorice root.
Again, it's important to talk to your doctor about which supplements are right for you—and which you should avoid.
