What Happens When Your B12 is Extremely Low?
                                
                                
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                                    3 min read                                
                            
                                According to the National Institutes of Health, vitamin B12 deficiency can go undetected for years and may even occur without causing anemia, with severe symptoms only appearing after significant health damage has occurred. This is because your body can store B12 in the liver for several years, masking the early signs of a problem.