Background: Vitamin B12 (VB12) deficiency is a pleomorphic disease with a wide range of manifestations. Its major cause is pernicious anemia, an autoantibody-mediated disease that results in low levels of intrinsic factor [1,2]. Case Presentation: We present a case report of a middle-aged man with severe megaloblastic anemia due to VB12 deficiency in relation to an unsuspected Crohn’s disease with exclusive ileum involvement. He also had some unusual neurological manifestations of this vitamin’s deficiency, such as hypersudoresis. Unlike most cases, the anemia was not hypoproliferative and hemolysis existed. Conclusion: This case reports some unusual aspects of VB12 deficiency and reminds us that ileum disease should be considered in patients with a negative autoimmune profile.

Keywords: Crohn’s disease, vitamin B12 deficiency, case report, weight loss, night sweats, anemia