IUBio Biosequences .. Software .. Molbio soft .. Network News .. FTP


Richard Kondo rkondo at ephys.ucla.edu
Mon May 6 11:22:29 EST 1996

Bert Gold wrote:
> Dima,
> My reading of the aforemented PNAS paper by Levine et al., (1996)
> disagrees with the very high dose vitamin C protocols which were
> advocated by Pauling and Szent-Gyorgyi, without providing any firm
> evidence on the issue, and without mentioning these great
> investigators by name.
> Conclusions in the PNAS paper are limited to a new RDA for
> ascorbate for men in their 20s.
> Bert Gold
> San Francisco
> Dima Klenchin (klenchin at macc.wisc.edu) wrote:
> : Q: is it really confirmed by research, or the current state of affair
> : is simply that kilogram amounts of ascorbic acid don't hurt (apparently)?
> : - Dima

	One repeated criticism regarding the ascorbic acid 
hypothesis is that ascorbic acid (AA) is water soluble, which means 
that absorption of AA would probably occur via a transport 
mechanism.  Such a mechanism would be saturable, and therefore, the 
body might not be able to absorb the mega-dosages of AA which Dr. 
Pauling advocates (well, advocated).  In a very rapid scan of 
Medline, I found studies measuring AA uptake in astrocytes, cornea 
cells, epithethial cells with evidence showing a Na+ dependence of 
AA uptake as well as inhibition of transport by various anion 
transporter blockers.  However, I don't know the gold standard 
studies nor do I have the knowledge to judge the quality of studies 
in this area?

	At what level is AA transport across gut epithelial 
membranes saturated?  How does it compare with estimated 
concentrations of AA in the gut at the mega-dosages suggested by 
Linus Pauling?  Moreover, Dr. Pauling said that the proper amount 
of AA should be titrated to just below a threshold which causes 
diarrhea.  Does this imply that not all of the recommended AA is 
not absorbed and that some of its beneficial impact is achieved in 
the colon.

Richard Kondo
Cardiovascular Research Lab

More information about the Glycosci mailing list

Send comments to us at biosci-help [At] net.bio.net