Causes of Vit. B12 deficiency megaloblastic anemia-
Fish tapeworm competes with cells in the ilium for vitamine B12 there by causing its defficiencyin the body. Reference:Exam preparatory manual for UGs by Ramdas Nayak Page no.:256
Fish tap worm infestation
Dilantin therapy
Gastrectomy
Ileal resection
Haematology