The vitamin "misnomer" really confuses me. I don't think if it was called "hormone D" that people would be snaffling it up trying to self-medicate.

Anyhow, I've googled and googled but still can't figure out why it's called a vitamin at all. The best I can come up with is that there IS an actual vitamin D that comes from the sun, but it helps the kidneys produces the good "hormone D" which is the what people are deficient in.

Can anyone shed some light on this? My description above could be a million miles off.

You can get it through food as well. The name was given when science was not as developed as today. Finally, names tend to stick once given.