As far as I understand it, Vitamin D deficiency could well occur throughout the British population, particularly in the winter months.
Most of our Vitamin D does not come from food, though there are some good sources (oily fish, eggs, for instance). Most of it is manufactured by the exposure of our skin to sunlight. The process involves the cholesterol in the fat under the skin, I think - those who know better please correct me!
Anyway, it seems that in the winter at more northern latitudes (which includes GB) the sun is not strong enough for us to manufacture Vit D; we cover up too much because of the cold, anyway, and we don't get out enough. Also older people are less efficient at manufacturing it - so by the end of the winter many of us are deficient in it.
You're lucky to get a test - my surgery won't do it because they're too expensive! I Googled 'Vitamin D deficiency', and 'Vitamin D3', and got quite a number of interesting peer-reviewed articles - sadly I've lost the links! The result is, that I take Vit D3 supplements all year round, 5000IU in the winter and 2500IU in the summer (unless I'm getting a lot of sun), both of which are way over the RDA. I'm not dead yet!
It's worth reading around and getting good information. There's been quite a lot of work done on safe levels of Vit D. If I can find the link in this tip I call my office, I'll post it.
Viv 8)
PS Lovely day here today - I might risk exposing a bit of skin :shock: Only my arms, though :lol: