Iron deficiency can be caused by a variety of parasites, including hookworms, tapeworms, and certain types of roundworms. Hookworms can attach themselves to the walls of the intestines and feed on blood, leading to anemia. Tapeworms can cause malabsorption of essential nutrients, including iron, leading to deficiencies. Roundworms, such as whipworms and pinworms, can live in the intestines and cause malabsorption. Additionally, some parasites like Trichuris and Strongyloides can cause iron deficiency anemia due to their damaging effects on the intestines. All of these parasites can be spread through contaminated food or water, contact with infected animals, or contact with soil or sand. Treatment of the underlying infection is necessary to address the iron deficiency.