About 50 years ago mention was made in some weekly reader or something
about how research on Vit. D was sparse.  Yet, what had been learned
indicated that this nutrient just might be extremely important in many
ways.  However, its un-patentability made greater research unlikely or at
least very slow.  Since then I have been on the lookout for more info on
Vit. D.  Only since computers became easily accessible have I been able to
get much more information.  Now there is tons of info and it nearly all
points to a really great need for more of this nutrient for nearly
everyone.  It seems it may actually be some sort of master nutrient.  There
is much to be learned, but the site www.vitamindcouncil.com will be very
enlightening.  What is going on is that information that could once be
suppressed for the money interests of the few, can now be publicized far and
wide by computers.  And it is being publicized.  Similar to the information
about the connection between iodine deficiency and cancer, along with loads
of other easily preventable poor health conditions.  My opinion--considered
and informed.  Not medical advice.    pj