Here are 2 web-links I'd like to share:
First mongongo nuts, the staple of the !Kung (real bushmen)
http://www.naturalhub.com/natural_food_guide_nuts_uncommon_Ricinodendron_rau
tanenii.htm

(I'm afraid the line above will split, so you've to complete the url with
the rest, like "taneii.htm". )

Then after all the discussions we had about Vitamin B12.
The ultimative B12 link. Very complete, covers many aspects like
b12 from seaweeds, from dairy, from oral cavity , from intestine bacteria.
http://www.veganoutreach.org/health/b12.html
The first pages tell how it all works.
The paper advocates B12 supplementation for vegans.
One point if critic: What is considered fixed in the article is the RDA (2.4
ug/day) and the serum levels to be considered normal (> 200ng/l).

However the intake/turnover seems to be very dependant on the amount lost
with bile (this is why vegans often have sufficient for 20-30 years).
Then serum levels... I feeled very well with 150ng/l.
Case Studies show deficiencies below about 100ng as I recall
(but the text "uncovers" deficiencies if beyond the definition of 200ng).
Very good reading for who's interested in the topic.

Regards, Amadeus