Hi! I just got it to work on Windows 10 without changing any security settings.
Hope it helps somebody! 
docker run -v /User/Documents/directory-to-share-on-host:/dir-on-container image/name ls
it’s really strange as if there is some kind of link or shortcut defined for path for current user. I don’t know why but it works just like that!
Just drop the /c/Users/username and replace it with /User/
/c/Users/username/directories -> /User/directories