www.17harleystreet.co.uk - Vitamin D has been known about for many years and is often called the "Sunshine Vitamin". Simple exposure to sunshine and eating a diet with plenty of oily fish, are the best ways of getting Vitamin D. It is thought that one billion people are deficient in Vitamin D - that is a stunning number! One in six of the world's population are deficient in a Vitamin, that few of us think about and doctors rarely test for.