From: sbharris@ix.netcom.com(Steven B. Harris)
Newsgroups: sci.med.nutrition,alt.support.skin-diseases
Subject: Re: Vitamin B2 Toxicity??
Date: 3 Mar 1998 03:37:22 GMT

>Reuters recently reported about an article in the Journal of Neurology
>where migraine headache sufferers received substantial relief after
>three months of taking 400 mg of Vitamin 2 daily.
>
>400 mg -- DAILY! -- is ALOT!
>
>Do ANY reports of Vitamin B2 toxicity exist?  Years ago Patricia Hauser
>commented that she couldn't find any such reports to include in her
>book, "The Right Dose."  However, she extensively discussed overdoses of
>other B vitamins, particularly B6.


   Riboflavin is a precursor for some potential free radical adducts,
and I've seen on report of a strain of mice that gets retinal disease
when given riboflavin supplements, apparently from this mechanism.

   I know of no other reports that even suggest that riboflavin has any
problems.  I have my doubts, BTW, that you can absorb more than about
50 mg at a meal, however, as the transport system in in the intestine
is active and saturable.  So you probably waste any excess over that in
a single dose-- the excess doesn't even make it to your urine.  Not
that the stuff is expensive enough for you to care.  Still, it makes me
wish the people picking the doses in these megadose studies put some
thought into it.


                                          Steve Harris, M.D.