What is a critical level of B12?
                                
                                
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                                    2 min read                                
                            
                                According to the National Institutes of Health (NIH), a vitamin B12 deficiency, characterized by serum levels below 200 picograms per milliliter (pg/mL), affects a significant portion of the adult population. A critical level represents a severe stage of this deficiency that can lead to profound and potentially irreversible health complications.