<prompt> Causes of Vit. B12 deficiency megaloblastic anemia-Fish tap worm infestationDilantin therapyGastrectomyIleal resection  <response>: 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 