Liver disease: often macrocytic, may see target cells
Alcoholism: BM suppression & macrocytosis independent of folate/B12 defic. or cirrhosis
Reticulocytosis
Other causes: hypothyroidism; MDS; meds that impair DNA synthesis (zidovudine, 5-FU, hydroxyurea, Ara-C); hereditary orotic aciduria; Lesch-Nyhan synd.