Is tart cherry juice bad for a person with kidney dysfunction?

It is difficult to answer this question without knowing what you mean by "kidney dysfunction". Cherries are a great source of antioxidants and phytochemicals, and are considered "medium" potassium fruits. A half cup of sweet cherries contains approximately 131 mg of potassium. However, if you have potassium and/or fluid restrictions in a later stage of CKD, cherry juice may not be an appropriate drink choice.