Final answer:
The statement that Vitamin B12 cannot be absorbed without intrinsic factor is true, as intrinsic factor is essential for the absorption of B12 in the small intestine, specifically in the terminal ileum.
Step-by-step explanation:
The statement that Vitamin B12 cannot be absorbed without intrinsic factor is true. Intrinsic factor is a glycoprotein secreted by the parietal cells of the stomach lining and is vital for the absorption of vitamin B12. Without intrinsic factor, vitamin B12 remains unbound and susceptible to degradation, and it cannot be absorbed by the small intestine. This absorption happens in the terminal ileum, where the intrinsic factor-vitamin B12 complex binds to specific receptors and is taken up by endocytosis. This process is critical for the production of mature red blood cells and normal neurological function. Without adequate B12 absorption, a person could develop conditions such as pernicious anemia. For individuals who cannot produce intrinsic factor or who have had a total gastrectomy, external sources of vitamin B12, such as injections, are necessary for survival.