David Wolfe reports that typical raw vegan diets are deficient and often
fail (he is critical of natural-hygiene-style diets), but that raw vegan
diets with added supplements and (high priced) superfoods have a
better chance of success:

http://www.fredericpatenaude.com/interview-wolfe.html

Of course, if raw vegan diets are "most natural" then one would not expect
to need supplements or superfoods on such diets. Wolfe is not alone in
pushing supplements and superfoods - Viktoras, Cousens  and Clement/
Hippocrates promote them, even Ann Wigmore if you count wheatgrass
as a superfood.

Tom Billings