Hello, Eating chalk is called pica (eating non-digestible materials) and in itself, it may cause gastrointestinal symptoms (abdominal pain, nausea, vomiting, etc) but also respiratory symptoms such as cough and shortness of breath. It is unlikely to cause kidney problems. On the other hand, it is important that you do a check to rule out anemia and certain nutritional deficiencies as patients that have these deficiencies are more prone to eat non-digestible materials such as chalk. I hope this answers your query. I remain at your disposal for further medical assistance. Regards, Dr. Antoneta Zotaj General and Family Physician