This group of vitamins was originally thought to have only one chemical form; the different vitamins became distinguished by each having a number added to the name.

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The B-vitamins were originally thought to have only one chemical form, and the different vitamins in this group were distinguished by each having a number added to the name, such as B1 (thiamine), B2 (riboflavin), and so on.

This Group of Vitamins Was Originally Thought to Have Only