evidence: While sampling one of the otherwise tasty chewable vitamin D supplements, I did a rush-read on the accompanying literature. There was mention of sheep, lanolin and something called Quali-D. What? A vitamin supplement made from sheep’s wool? How could this be? [...] Well, if you are, as I was, curious to know how Jamieson derives vitamin D from the wool of sheep, read on for the step-by-step explanation I later got from Michael McBurney, Head of Scientific Affairs for DSM Nutritional Products, the company which supplies the ingredient to Jamieson: "Only vitamin D3 comes from wool from sheep. Some brands use vitamin D2 which comes from non-animal sources and is different from the vitamin D humans can synthesize from sun exposure. "DSM Nutritional Products’ natural-source Vitamin D3 is sold in crystalline, oil and powder forms. It is derived from lanolin taken from the wool of healthy live sheep living in Australian and New Zealand. An October 2003 Note for Guidance, adopted by the Committee for Proprietary Medicinal Products and the Committee for Veterinary Medicinal Products, states that derivatives of wool and hair from ruminants, such as lanolin, are compliant for use as natural-source supplements provided the wool or hair is taken from healthy, live animals.