This was straightforward enough: vitamin B6. Carpal tunnel syndrome was endemic among my fellow data entry workers in XYZ insurance company’s workers’ comp processing department. About every tenth woman there (we were 98% women) wore a wrist brace. I escaped their fate until a few years later at another typing-intensive job, by which time I had already heard about the connection with vitamin B6.
I don’t remember how much I used, but it wasn’t crazy — maybe 100 mg a day? I might also have been taking B-complex, which would be another 50 mg of B6. It didn’t take long to work — a month at most. I continued to take it long after the pain disappeared, as I was nervous about the possibility of the pain returning, since I was still a keyboard slave. But eventually I did and the carpal tunnel never returned.
A more active form of vitamin B6, P5P (pyridoxal-5-phosphate), might be called for if you have no luck with regular vitamin B6.
I also discovered early on that I cannot use a center-placed trackpad on a laptop. Just 10 minutes contorting myself with that thing makes my arms hurt. I’m also careful not to get the mouse, and thus my elbow, too close to my body when I’m working at the computer. (Check out this guy who avoids the mouse entirely by using not one but two Apple Magic Trackpads, one on each side of his keyboard.)