If you have kidney problems, you must be careful with dietary supplements. Supplements to avoid with Kidney Disease include high-dose vitamin C, which can increase kidney stone risk, and vitamin A, which may build up to toxic levels. Protein powders and creatine can overwork damaged kidneys. Potassium, phosphorus, and magnesium supplements may cause dangerous mineral imbalances if taken without medical advice. Certain herbal products such as licorice root, horsetail, and aristolochia can harm kidney tissue. Always consult a healthcare provider before using any supplement to protect kidney function safely.