Hello dear, Chalk contains calcium carbonate which if taken in excessive amount can cause stone formation in kidneys. The continuous craving for eating inedible substances (like chalk, slate pencils) is known as Pica. It is one of the features of Iron deficiency anemia. This has already been detected in your basic blood tests. Investigations like peripheral blood smear will be helpful in determining the type of anemia. Based on the reports, management will include administration of supplemental Iron & Folic acid preparations. There can be associated factors like hookworm infection which needs to be managed with Albendazole preparations. Also you need to take a healthy balanced diet rich in green leafy vegetables. So, kindly consult your General Physician for proper clinical evaluation. Wishing you a good health. Take care.