In article ,
Janet Baraclough.. wrote:

Science has not stated that sunshine is bad for you. Northern
Europeans require it to utilise vitamin D and avoid rickets, and also to
stimulate melatonin production and avoid SADS. The warning is
specifically against over-exposure leading to sunburn.

Yes, precisely.

There is a great deal of evidence that a tan does give SOME
protection against melanoma.

Could you provide a web reference for that evidence?

I am afraid not. The ones that I saw were in the medical literature,
and not phrased in that way (though it was pretty obvious to anyone
with a clue about statistics). The evidence is twofold:

The common skin cancers tend to be on the parts of the body most
exposed to the sun - especially the bridge of the nose. Melanoma
is relatively more common on the trunk and others areas that are
intermittently exposed. If I recall, it is particularly common on
the back of the thighs (a protected location for workers, and very
exposed when lying face down).

Outdoor workers (including those who work bare-chested in the UK,
and in the tropics) have the rate of the common ones you would
expect from a direct exposure link, but a very much lower rate of
melanoma. If I recall, comparable to the general public, though
perhaps a bit higher (see below for the consequences).

However, that is the sort of tan
you get from regular outdoor work,

AIUI Outdoor occupations (such as farming) have a higher incidence of
all skin cancers, than indoor occupations.

As I say above, that is definitely so for the common skin cancers,
but I believe that it is either much less so or not so for melanoma.
I can't remember whether the figures I saw were balanced for sun
exposure, which is a significant point.

To check if tanning has a protective effect, you need to compare
outdoor workers with indoor workers who expose themselves comparably
at less frequent intervals. Including the significant proportion
of the population that avoids the sun entirely obviously brings the
rate down.

The only farmer that I know who died from melanoma was a soldier in
North Africa during the war (and was blue-eyed and fair-haired).
That episode is known to account for a considerable excess in the
statistics, and was definitely in the "lobster roasting" class.


Regards,
Nick Maclaren.