The evaluation should determine if the anemia is of acute or chronic onset, and clues to any underlying systemic process should be sought. Iron deficiency is the most common cause of anemia. In children, the deficiency is typically caused by diet. Ferrous salts of iron are absorbed much more readily and are generally preferred. All three forms are well absorbed.
Ferrous sulfate is the least expensive and most commonly used oral iron supplement.
For iron replacement therapy, a dosage equivalent to 150 to 200 mg of elemental iron per day is recommended. Hematocrit levels should show improvement within one to two months of initiation of therapy. Since body stores of vitamin B12 are adequate for up to five years, deficiency is generally the result of failure to absorb it. Pernicious anemia, Crohn's disease and other intestinal disorders are the most frequent causes of vitamin B12 deficiency. Symptoms are attributable primarily to anemia, although glossitis, jaundice, and splenomegaly may be present.