Ferrous sulfate is a type of iron. You normally get iron from the foods you eat. In your body, iron becomes a part of your hemoglobin (HEEMoglobin) and myoglobin (MY oglobin). Hemoglobin carries oxygen through your blood to tissues and organs.Myoglobin helps your muscle cells store oxygen. Folic acid helps your body produce and maintain new cells, and also helps prevent changes to DNA that may lead to cancer. Ferrous sulfate and folic acid is used to treat iron deficiency anemia (a lack of red blood cells caused by having too little iron in the body).