Hacker News Reader

Very useful, thank you.

This is simply a result of how vitamin D is manufactured, and the lack of sunlight in northern latitudes.

It was specifically the NHS advice I was questioning, I'm aware of the basic cause. Thanks.

You can see the development of the UK guidance.

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-...