Dietary and herbal supplements are widely used, perceived as safe, and promoted for therapeutic potential and correction of nutrient deficiencies. However, they may be harmful for people with CKD due to ingredients that are only partly scrutinized by regulatory agencies.1-3 Supplements may be inaccurately labeled, interact with each other and/or prescription medications, or contain nephrotoxic substances. Renally eliminated supplements and metabolites may accumulate in CKD, leading to adverse outcomes.