If you're talking about being able to call yourself a Certified Raw
Nutritionist or something like that, you might want to do some
research at
your local library.  My understanding is that, in many fields, anyone
can
put together a certification -- just make one up.  They are often put
together by businesses who train people on their systems, for example.
A
certification, therefore, can be very meaningful, completely
meaningless, or
anything in between, depending on who put it together.  A license is a
different matter.  It almost always involves governmental regulation
and
testing.  (This doesn't mean, of course, that it's always a reflection
of
real skill and useful knowledge, but it does have legal oomph.)  The
last
time I checked, there wasn't even a licensure program for
"nutritionist" in
most US states, so it'll be a long time, I'm sure, before there is
governmental recognition or regulation of anything like a raw food
expert.

If you're in the USA, the following link may be of help.
http://www.looksmart.com/eus1/eus317836/eus317916/eus64407/eus53476/eus282281/eus287113/eus282309/r?l&&hl=6&ss=1&key=licensing

Good luck!

:)
Carol