Answer : A Alcoholism
Macrocytic anemia may be caused by impaired DNA synthesis due to a deficiency of folic acid or vitamin B12.
This results in abnormal nuclear development, which, in turn, leads to ineffective erythrocyte maturation and macrocytic anemia.
Folic acid deficiency is most commonly due to inadequate dietary intake, which often develops in patients with poorly balanced diets (e.g., alcoholics).
Other possible causes of macrocytic anemia include liver disease, hypothyroidism, and primary bone marrow disease. None of the other choices are associated with macrocytic anemia.
Chronic disease and renal disease cause normochromic, normocytic anemia. Iron deficiency and thalassemia are microcytic anemias.