What is vitamin B12 deficiency disease called? Exploring pernicious and megaloblastic anemia
                                
                                
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                                    3 min read                                
                            
                                According to the National Institutes of Health, vitamin B12 deficiency can affect a significant portion of the population, especially older adults. When this occurs, it can manifest in several ways, but what is vitamin B12 deficiency disease called, and how do medical professionals classify the condition?