Vitamin D in sheep's Lanolin

This video from 123HomeFree talks about utilizing Vit D made naturally in sheep wool.  He doesn't wash the wool and says he wears it and gets Vitamin D from the wool.    

I read that sheep shearers had to be careful about Vitamin D toxicity from shearing alot of sheep and handling their wool.  I am wondering if I saved wool from my sheep (I only have 2 each year for meat), how long the vitamin D stays in the wool and maybe just working with a bit of wool several times a week would provide adequate vitamin D?  

That's very, very interesting.

People in northern winter climates are often Vitamin D deprived, which is a health concern.

Also, I know people with psoriasis who are prescribed an expensive ointment with a specific formulation of Vitamin D to suppress the condition. Hmm!