It depends. It is very important to know what kind of anemia and what causes it. Iron deficiency is one of the main causes but there are others: vitamin b12/folate deficiency, chronic disease like infection or cancer, genetic conditions, certain medications, toxins, etc. Consulting with your doctor or a hematologist for proper testing and diagnosis is a must before starting any treatment.
Depends. It depends on what kind of anemia you have , is it due to blood loss, iron deficiency, anemia of chronic disease, sickle cell anemia, is it due to bone marrow failure, vitamin B12 deficiency; some anemia will never be cured (sickle anemia) due to it's genetic origin; however if it is due to blood lost, it should be corrected immediately when you received a blood transfusion for example.