Folate deficiency in Crohn's disease: incidence, pathogenesis, and treatment.

Megaloblastic anaemia due to folate deficiency is a well- recognized complication of idiopathic steatorrhoea and acute tropical sprue. These conditions are characterized by abnor- malities of mucosal structure and absorptive function of the proximal small intestine, the principal site of folate absorption. On the other hand, in patients with anatomical lesions of the small intestine such as blind loops, strictures, and ileal re- sections, megaloblastic anaemia, if it occurs, is almost invariably due to vitamin B., deficiency (Mollin, 1960).