How Much B12 Is in B100? Deciphering B-Complex Supplements
                                
                                
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                                    4 min read                                
                            
                                Many vitamin B complex supplements labeled "B100" contain 100 micrograms (mcg) of Vitamin B12 per serving, alongside 100 milligrams (mg) of several other B vitamins. This common formulation can be confusing, but understanding the label is key to proper nutrition.