Vitamin D deficiency - Which value important?

[Gerenuk]

I'm not getting much sun here so I checked my Vitamin D levels some time ago.
They determined
16 ng/ml for Vit D 25 and
47 ng/l for Vit D 1,25
Apparently the first value signals a deficiency, but not the second. I read one should usually do only the first check (as it's cheaper), but on the other hand the second form is what is the final biologically active form.
So do I need the solarium after all? :)

 

[fileen]

We are just now covering Vit. D. in my nutrition course. We were not given specific values, and I am certainly not an expert, but my proff was saying that recent research has suggested that the current suggested amount of vit. D. is too low and that it is in the process of being re-evaluated. He discussed the trends for people in colder climates and how we (Im Canadian, but he included anywhere that requires covering up and less sunlight) should be supplemented in the winter months. We just started getting into how vit. D. affects bone density. My proff suggested consuming fish oils as a natural supplement that does not have the same risks associated as UV exposure. Unfortunately nothing is quite as effective as the sun, however 15 mins of afternoon sun should do it, and a person should never burn themselves in attempt to get more vit. D. I remember being told that strawberries have lots in them, but you have to eat loads of them every day to get the required amount. I don't know if that's true or not though. Do you live in a sunny area? Do you have a job that requires you to be locked away indoors while the mid day sun is blazing down?

 

[Gerenuk]

So fish oils instead of taking the real food that contains Vitamin D?
Germany isn't exactly sunny - for sure not in winter. An office job doesn't get me outdoors. I even read that common glass absorbs most of the UV, so sitting behind glass isn't going give much Vitamin D?!

 

[Count Iblis]

The Sun needs to be higher than about 40° above the horizon for enough UV light to get through. This means that if you live at 50° Northern lattitude, you can only get vitamin D from the Sun in the months May, June, July and August, and that only in the afternoons.

So, if you are in the office from 9 to 5, you won't get any vitamin D from the Sun, not even in the summer.

 

[fileen]

So fish oils instead of taking the real food that contains Vitamin D?
Germany isn't exactly sunny - for sure not in winter. An office job doesn't get me outdoors. I even read that common glass absorbs most of the UV, so sitting behind glass isn't going give much Vitamin D?!

The proff says that lots of foods boast of containing vitamin D, but its not all digestible and you end up absorbing a lot less than you would think. I have the biochemistry of it in my notes, but Id need his permission to post it, and to be honest I don't fully understand it and I am not required to for the course. I guess its the same sort of thing as when people think they get all sorts of iron from spinach when in reality 99.9% is indigestible and just goes right through you. Animal sources are apparently the best after the sun and only some animals (mainly fish) have the vit D we need and use. Its funny you say Germany because he showed some data from a study done in Germany as an example of a place that has little sunlight. They tested vit D levels and bone density for a year in two samples of people, then they did the same the following year and supplemented one of the groups with vit. D. The supplemented group had much higher bone density. In Canada we are in much the same situation.