<prompt> Vitamin B12 is absorbed inDuodenumJejunumIleumColon  <response>: Most vitamins are absorbed in the upper small intestine, but vitamin B 12 is absorbed in the ileum.This vitamin binds to IF and this complex is absorbed across the ileal mucosa.Vitamin B12 and folate absorption are Na independent.Ref: Ganong;s Review of medical physiology, 23 rd edition, page 458 