9 Vitamins & Supplements That May Affect Your Liver and Kidneys If Misused
Vitamins and supplements can be helpful when used appropriately, but “natural” does not always mean safe. Taking large doses, combining several products, or using supplements when you have kidney or liver problems can sometimes cause harm.
- Vitamin A — Excessive amounts, especially preformed vitamin A, can damage the liver and cause other problems.
- Vitamin D — Very high doses can raise calcium levels and potentially damage the kidneys.
- Vitamin C — Large amounts can increase the risk of kidney stones in some people.
- Vitamin B3 (Niacin) — High doses can cause liver injury, particularly with some prescription-strength preparations.
- Iron — Taking more iron than your body needs can cause serious toxicity and liver damage.
- Calcium — Excessive supplementation may contribute to kidney stones and, in certain circumstances, high blood calcium.
- Green tea extract — Concentrated extracts have occasionally been associated with liver injury, particularly at high doses.
- Herbal supplements — Some herbal products can contain compounds that affect the liver or kidneys, and their contents may vary between products.
- High-dose bodybuilding or weight-loss supplements — Some products may contain multiple ingredients or undeclared substances that can put stress on the liver or kidneys.
Smart Safety Tips
- Follow the recommended dose on the label unless your healthcare professional tells you otherwise.
- Avoid taking several supplements containing the same vitamin or mineral.
- Tell your doctor or pharmacist about every supplement you take.
- If you have kidney or liver disease, ask a healthcare professional before starting a supplement.
- Seek medical attention if you develop symptoms such as yellow skin/eyes, unusually dark urine, severe vomiting, confusion, or significant changes in urination.
