Take these vitamins with caution: Doctors warn of side effects
Vitamins that can harm the kidneys identified (photo: magnific)
Some dietary supplements can, under certain conditions, place additional strain on the kidneys or worsen their function. This mainly concerns products with high doses of vitamins and minerals, as well as some popular sports supplements, according to Eating Well.
High-dose vitamin C
High doses of vitamin C may seem like a simple way to support the immune system, but they can create an additional burden on the kidneys.
Many people consider vitamin C harmless because it is water-soluble, but megadoses can actually become problematic for kidney health, especially for people who already have kidney disease or a history of kidney stones.
Excess vitamin C can be converted into oxalate in the body, and elevated oxalate levels may contribute to the formation of kidney stones.
Therefore, taking high doses above 1000–2000 mg per day is not recommended.
It is better to obtain vitamin C from food sources instead.
High-dose vitamin D
Although vitamin D is essential for bone health, immunity, muscles, and nerves, excessive intake may place stress on the kidneys. It can lead to elevated calcium levels in the blood, which may contribute to kidney stone formation.
The tolerable upper intake level for adults is 4000 IU per day. For most people, supplementation should be individualized based on laboratory tests.
Herbal supplements containing aristolochic acid
Aristolochic acid is a well-known kidney toxin and carcinogen, directly linked to cases of kidney failure.
Some herbal supplements may not clearly disclose all ingredients. Therefore, extra caution is needed when choosing such products.
St. John’s wort
St. John’s wort is a herbal supplement commonly used to relieve symptoms of depression. Despite its benefits, it may pose a serious risk for people with kidney disease.
People with chronic kidney disease are often advised to avoid it, as it can interfere with medications.
High-protein supplements
For healthy individuals, protein powders are generally considered safe when taken in appropriate amounts. However, for people with chronic kidney disease who are not on dialysis, high protein intake may overload the kidneys.
Excess protein from supplements, bars, and powders may contribute to kidney stone formation and accelerate kidney disease progression.
Other tips for kidney health
Maintaining kidney health is not only about avoiding certain supplements. Daily habits also play an important role:
- Limit sodium intake — too much salt can raise blood pressure, a major risk factor for kidney disease
- Choose quality protein sources — opt for whole plant proteins such as beans, nuts, seeds, tofu, or edamame
- Drink enough water — dehydration can contribute to kidney stones (needs vary per person)
- See a doctor regularly — kidney disease can progress silently for years, so monitoring blood pressure, glucose, creatinine, and urine protein is important
This material is for informational purposes only and should not be used for medical diagnosis or self-treatment. Our goal is to provide readers with accurate information about symptoms, causes, and methods of detecting diseases. RBС-Ukraine is not responsible for any diagnoses that readers may make based on materials from the resource. We do not recommend self-treatment and advise consulting a doctor in case of any health concerns.
