Here's some info from Drug information site.

alfacalcidol Pronunciation: al-f-kalsi-dol A derivative of vitamin D used in 
the treatment of hypoparathyroidism, vitamin D-dependent rickets, and rickets...
Medical Dictionary (Stedman's
  ----- Original Message ----- 
  From: Kirsteen Wright 
  To: silver-list@eskimo.com 
  Sent: Friday, August 28, 2009 11:03 AM
  Subject: CS>OT Vit D


  Sorry this off yopic but I really don't know where else to ask. I believe 
we're probably all short of Vit D especially here in Scotland. I'd ordered some 
supplements (Biolife Vit D3) and started taking them. I persuaded my doc to 
test my blood levels (no idea what test they actually did) and he agreed I 
wasmarginally low. so prescribed One-Alpha 0.25mcg alfacalcidol. now I may just 
be highly suspicious of the medical profession but this looks more like a 
medicine than a drug and I'm finding it very hard to get any info on it. Does 
anyone know anything about it?

  thanks
  Kirsteen