Iron deficiency anemia is a common type of anemia that can be treated with iron supplements like ferrous sulfate or ferrous gluconate. Slow release supplements are recommended for patients with conditions like Crohn's disease or ulcerative colitis that can interfere with iron absorption. Other types of anemia include aplastic anemia, which requires bone marrow transplantation or immunosuppressant drugs, sickle cell anemia treated with drugs like hydroxyurea or bone marrow transplants, and pernicious anemia treated with vitamin B12 injections or supplements since it results from B12 deficiency.