Supplement

Health authorities in England are starting to feel there is a lack of vitamin D intake for approximately one fifth of the population. The 10 microgram per day recommended is only partially filled by food (3 to 5), the rest - meant to be derived by sunlight - is hard to get. Climate change may be affecting the level of sunlight received.

source: Le Figaro, from The Independent

http://www.lefigaro.fr/sciences/2015/08/03/01008-20150803ARTFIG00207-grande-bretagne-le-manque-de-soleil-pourrait-devenir-un-probleme-de-sante-publique.php