Vitamin D deficiency is very common especially in people who spend their daytime hours inside and also in dark skinned people living in northern latitudes.
In the UK doctors recommend everyone takes a vitamin D supplement in the winter.
In the UK doctors recommend everyone takes a vitamin D supplement in the winter.
There's a consensus statement from 2010, here: https://www.nhs.uk/Livewell/Summerhealth/Documents/Concensus...
And there's discussion of the new guidelines (with links to the newer research) here: https://www.nhs.uk/news/food-and-diet/the-new-guidelines-on-...