Doctors Say These Everyday Supplement Errors May Raise the Risk of Kidney Injury and Harmful Drug Interactions

This article is not a substitute for medical advice. Ask your doctor about the right approach for your individual health.

Your kidneys are essential for filtering waste and regulating fluids, making kidney health a key part of staying well over the long term. Many things can harm kidney function, including poor diet and not drinking enough water. Another often overlooked concern is taking certain supplements incorrectly or in excessive amounts. Supplements can help fill nutritional gaps, but some products can pose safety risks, especially for the kidneys.

We spoke with pain management physician Sean Ormond and dietitian Krutika Nanavati about several common supplement mistakes that could cause problems for kidney health over time. Their warnings range from risky combinations to too much protein powder.

" alt="" />

1. Mixing Vitamin E and Vitamin K

Vitamin E and vitamin K both support important functions in the body. Vitamin K helps maintain strong bones and plays a major role in blood clotting, while vitamin E is important for vision, reproductive health, and brain function. When these nutrients come from food, they can be part of a healthy diet. But Dr. Ormond says high-dose supplements of both should not be taken together.

“Vitamin E and vitamin K are both fat-soluble vitamins that can interact with each other,” he explains.

“Taking high doses of both vitamins together can increase the risk of blood clots.” One study also notes that, because both nutrients are deeply involved in coagulation, extreme cases of this interaction can lead to abnormal blood clotting.

Vitamin E has blood-thinning effects and can raise bleeding risk, while vitamin K is central to clotting. Large amounts of either one may interfere with the other and upset the balance needed for normal clotting. In addition, both vitamins affect the vascular system and may indirectly affect kidney function when overused.

" alt="" />

2. Taking Too Much Vitamin C

Vitamin C is widely known for supporting the immune system and overall health, but dosage matters. Nanavati cautions that excessive intake, especially more than 2,000 mg a day, may contribute to kidney stone formation, particularly in people who already have kidney problems.

Kidney stones can cause severe pain and may block the urinary tract, which can lead to infection and kidney damage. For most people with healthy kidneys, staying within recommended amounts is generally considered safe.

" alt="" />

3. Overusing Protein Supplements

Protein supplements are popular with people who want to build muscle or support athletic performance. Still, taking too much protein, especially through supplements, may have negative health effects, including on the kidneys. Nanavati says high protein intake can worsen kidney damage in people who already have kidney disease by increasing the workload on the organs. Since the kidneys filter waste produced during protein metabolism, too much protein can place extra strain on that process and may contribute to damage over time.

Experts stress that more research is still needed to fully understand how excessive protein affects kidney health. Healthy people are unlikely to see harmful effects, but anyone with existing kidney disease should be cautious and speak with a healthcare professional before greatly increasing protein intake, especially through supplements.

" alt="" />