Vit D

Ever wondered how animals make Vit D? 
Humans make vit D when our skin is exposed to sun light right?  So Animals and birds who have  fur and feathers? How do they make Vit D? Do they have diets which are so rich in Vit D already?

from this very interesting  page 

http://www.chm.bris.ac.uk/motm/vitaminD/vitamindjm.htmThe presence of fur in animals or feathers in birds blocks UV light from reaching the skin. So in these cases, the creatures’ skin secrete oils or waxes which coat and impregnate its fur or feathers. Sunlight then interacts with the oil and produces vitamin D, which is then ingested by the animal or bird when it grooms itself.

not only that apparently the Vit D tablets that we take comes from Sheep wool! 

Did also assume that the first humans were probably black? me too! Because today people in Africa are black and Humans came from Africa so they probably looked like how people look today! Right!

But Then someone clever pointed out that underneath the fur all animals are basically pink ( i.e white :P ) So the earliest ancestors of humans when they were just about losing the fur were probably pink skinned? so ancient humans were probably white!??!

Wiki says skin pigmentation evolved 1.2 million years ago and we can say Home Sapiens were probably dark skinned and our assumption was probably correct :-P Still it is all very interesting how our assumptions colour our beliefs.