Macrocytic anemia
Anemia caused by a lack of vitamin B12 can be prevented by following a well-balanced diet. B12 injections can prevent anemia after surgeries known to cause vitamin B12 deficiency. Early diagnosis and prompt treatment can limit the severity and complications of this anemia.
Antony AC. Megaloblastic anemias. Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 170.