<prompt> Vitamin B12 is required for a number of metabolic processes. Which of the following lesions would NOT lead to a deficiency of this vitamin?Chronic gastritis resulting in achlorhydriaAutoimmune destruction of gastric parietal cellsSurgical resection of the jejunumSurgical resection of the ileum  <response>: Absorption of vitamin B12 requires formation of a complex with intrinsic factor, which is secreted by parietal cells of the stomach. Destruction of these cells thus results in a vitamin B12 deficiency. The vitamin B12-intrinsic factor complex is absorbed in the ileum. Thus, surgical resection of the ileum, but not of the jejunum, will also produce a deficiency. Ref: Kaushansky K., Kipps T.J. 2011. Chapter 37. Hematopoietic Agents: Growth Factors, Minerals, and Vitamins. In L.L. Brunton, B.A. Chabner, B.C. Knollmann Eds, Goodman Gilmans The Pharmacological Basis of Therapeutics, 12e. 