The difficulties of understanding Vitamin C (or anything, for that matter)

When you learn things from your science textbook, it all seems so clear that it's a complete mystery why no one figured it out right away.  Of course life doesn't spontaneously generate. Of course gravity accounts for the movement of the planets. Of course scurvy is caused by a lack of Vitamin C.

Maciej Ceglowski recently wrote a superb essay about Scott's tragic expedition to the Antarctic, and  the contribution of scurvy, among many other problems, to that disaster. What, you say the scurvy problem had been solved back during the Napoleonic wars by the British navy? Why then are these limeys losing teeth over a century later?

The story is much more complex than that, it turns out.  Preventing scurvy was a pressing issue in sailing vessels on long voyages, but seemed less important on faster steam ships. For a variety of reasons, including where the citrus fruit came from and how it was processed, the British ended up with less and less effective versions of their scurvy preventer, but access to fresh food (most of it containing some Vitamin C) concealed this.

Until people started exploring the polar regions, and coming down with scurvy. What was wrong?

What if it was a disease carried by germs? Many otherwise mysterious diseases were explicable by this mechanism, so scurvy might well be one too.

Well, "might be" to you.  Physicians always "know" the causes of what ails us. Always. It's their essential nature. So physicians knew that scurvy was caused by spoiled meat, despite the huge ambiguities in the evidence.

Now, in fact, the role of scurvy in the Scott disaster is minor, and not even completely demonstrated. But the story of how confusing and unobvious the evidence was for Vitamin C deficiency as the cause of scurvy is the interesting part. Recommended.

(via the everflowing Kottke)