From: sjk@strl.labs.tek.com (Steven King)
Newsgroups: misc.kids
Subject: Re: RDA's  (was: Re: Dr.Spock and the Milk Controversy)
Keywords: Spock, Milk
Date: 15 Oct 92 21:04:40 GMT
Article-I.D.: crl.4837
Reply-To: sjk@strl.labs.tek.com (Steven King)
Followup-To: misc.kids
Organization: Software Technology Research Lab, Tektronix, Inc.

In article <1992Oct13.053238.7354@mnemosyne.cs.du.edu>, pciszek@nyx.cs.du.edu (Paul Ciszek) writes:
|> sgauch@ccs.northeastern.edu (Susan Gauch) writes:
|> 
|> >However, there was a study in England recently with 2 groups of children
|> >Both groups drank the RDA of calcium in milk.  One group also received
|> >a calcium supplement equal to another RDA.  After n years, the group
|> >receiving the supplement had noticeably more bone mass (a good thing).
|> >While the experimentors stopped short of upping the RDA for calcium,
|> >it seems like too much, in this case, is a good thing.
|> 
|> Remember folks, the RDA's are bare minimums, as in, "Get at least this much
|> vitamin C each day if you don't want to get scurvy".  The optimum amounts
|> are not known in most cases, or are debated.  Consuming many times the
|> RDA (a la Linus Pauling and vitamin C) is not a good thing, but exceeding
|> it by a little bit is desirable.

"Not a good thing" is relative.  In the case of certain fat-soluble vitamins,
it can be poisonous.  Too much Vitamin A, for instance, will build up in your
fatty tissues and can cause death.  Water soluble vitamins, on the other hand,
do not cause harmful effects.  They can, in large quantities, offset the
balance of other vitamins and minerals.  Minerals are the most sensitive
to the balance of other vitamins and minerals.  Vitamin C will promote
the absorbtion of Iron.  Too much Calcium will upset the balance between
Calcium and Magnesium.  This is not accounted for in the RDA system.

Many nutritionists believe that the source of the vitamin or mineral is
important.  For instance, it is widely thought that Iron tablets derived
from Spinach are more easily absorbed than Iron Oxides.  Some also
believe that an imbalance of natually derived vitamins is not as upsetting
to the system as are those derived from pure elements.

And then there are the bioflavinoids... the Vitamin A precursors.  You
can take many times the amount necessary for your body to manufacture
it's own Vitamin A, but the body will not convert any more than it needs.

I don't recall any negative imbalances or side-effects due to ingesting
1000 IU of Vitamin C (ala Pauling) per day.  If you have any references,
I would be interested to know.

We must be careful to get the facts and keep them in mind when using
supplements.  General statements such as "are a good thing" and "are not
a good thing" shed no light on the facts regarding vitamins and minerals.

BTW: I have found, for the most part, that Nutritionists know much more
about vitamins and minerals than do Pediatricians.  My pediatrician friend
keeps up with food supplements via articles in journals, which are narrow
and several years behind the state of the art in nutrition science.

Steven (sjk@strl.labs.tek.com)

"Sometimes if you have a cappuccino and then try again it will work OK."
(Dr. Brian Reid)  "Sometimes one cappuccino isn't enough." (Marcus Ranum)
"A double vanilla latte always works."  (Me)
Newsgroups: misc.kids,alt.postmodern