Trader Joe's recently peddled me a very attractive assortment of vitamin supplements, and in each self-contained valentine of pills were all the usual suspects reassuringly packaged together. The tiny ruby of the group, I thought, had to be something special, and indeed it was an old vitamin fave: Vitamin A. As a nearly legally blind person (but lively & w/excellent hearing!), I've always been after any talisman claiming to benefit one's eyes--even though I wasn't sure how much use I'd be able to get out of "improved night vision." A few weeks into my newly supplemented diet, I became intensely interested in the origin of my alphabet of pills. I learned that the vitamins were named according to the order in which they were discovered--okay, makes sense. But then I learned about how the Danish got involved and invented their own nomenclature rationale (thanks, ThinkQuest):

The first vitamins were discovered and named in alphabetical order, until a Danish researcher discovered and named vitamin K. He named it after the Danish word for clotting, Koagulation, because vitamin K helps the blood to clot. Meanwhile scientists had found that what they thought was a single vitamin B was really a group of vitamins that are usually found together in the same foods. So numbers were attached to the B. By this time, the last B vitamins were discovered and the system of letter naming was out of style. Thus, some of the B vitamins are called only by their chemical names.