On Fri, 22 Jan 2010 12:03:31 -0600, william <[log in to unmask]> wrote:
>
> A university study of schoolchildren during a winter in Edmonton,  
> Alberta showed that those who were exposed to the kind of fluorescent  
> light that is supposed to duplicate the spectrum of sunlight not only  
> got no dental cavities, but the little brown spots on teeth that show  
> beginning cavities disappeared.
>  From memory years ago, so no url.

You're probably thinking of this:   
http://www.eric.ed.gov/ERICWebPortal/custom/portlets/recordDetails/detailmini.jsp?_nfpb=true&_&ERICExtSearch_SearchValue_0=ED343686&ERICExtSearch_SearchType_0=no&accno=ED343686

And actually those results were from full spectrum lighting with  
supplemental ultraviolet lighting.  The attempt, of course, was to  
simulate sunlight, so the message to me is that kids need to be outdoors  
more.  ;-)

> I live at 46°N latitude, and spend an average of a few minutes outside  
> in sunlight each day.

I recall reading that it only takes 15 minutes of full body exposure each  
day to get "enough" sunlight for vitamin D synthesis, and proportionately  
longer as you cover up.   That's why vitamin D drops in the winter -- it's  
not uncommon on some of the coldest days to have everything covered but  
your eyes.

--
   Robert Kesterson
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