From: silver@fraser.sfu.ca (Craig Silver)
Subject: Re: Calcium/Magnesium
Organization: Simon Fraser University, Burnaby, B.C., Canada
Date: Wed, 16 Dec 1992 23:14:18 GMT

> You posted to the net recently that your professor suggested that North
> Americans do not have a dietary Ca deficiency, rather problems with
> dietary Vitamin D.  This is one I'm completely unfamiliar with.  The
> explanation?
> 
>  slj          yogurt@vmd.cso.uiuc.edu

This is a message I sent to the man who wanted more information
(cpr4k@holmes.acc.Virginia.EDU (Christian P. Roberts)).  If you'd like
me to go into it more, let me know and I'll tell you what I know.

cpr4k@holmes.acc.Virginia.EDU (Christian P. Roberts) writes: 

>     Yes, I would.  I am looking for a Calcium supplement that is not
> calcium carbonate, because I can't take the flatulence it produces.
> Calcium citrate is preferable.  One supplement that I found (Schiff, I
> think), had less vitamin D, but I noted that it contained calcium
> phosphate.  I asked about that below, because I read that it actually
> leeches calcium from thebones, and leaves you in a negative balance,
> if taken as the source of calcium.  Sodas have been implicated in this
> regard, as well, since they usually contain phosphoric acid.

I write (Craig Silver silver@sfu.ca):

I don't know much about the different forms of calcium but I can tell
you about "vitamin D".  I put it in quotes because it's not really a
vitamin in the true sense of the word.  Being a vitamin means that it
is an essential nutrient, meaning that our bodies cannot make it and
we have to therefore consume it.  This is not true of "vitamin D"
because our bodies *do* make it when we are exposed to sunshine (no,
we don't get "vitamin D" from sunshine directly).  What it *is* is a
potent steroidal hormone and its other name is calciferol.  Its name
comes from its function: to absorb calcium.

So you might ask why not take some "vitamin D" pills to absorb more
calcium?  The answer is a big NO.  The reason is that when this
hormone is consumed it goes into the chylomicron and into lymphatic
circulation (just like how the body handles consumed fats).  The
problem with this is that it *doesn't* go to the liver and kidneys to
get converted into the proper form of the hormone (the proper form BTW
is 1.25-dihydroxycholecalciferol).  In it's improper form, it actually
sends calcium to the soft tissues, like the arteries, instead of the
bones.  So North America's problem is actually not that we don't have
enough calcium in our bodies, but that the calcium is distributed to
the wrong body parts.

Fare skinned infants are at the greatest risk of the ill effects of
consuming "vitamin D" and many died in Britain because their milk 
was fortified with it.  It is a disease and is now called Pathological
Calcification.  This why Britain doesn't fortify their dairy
anymore.  You guys in the states have a choice between fortified milk
and nonfortified.  We in Canada don't, unfortunately.

On the other hand, those who are at risk of not getting enough
"vitamin D" are dark skinned infants living in northern parts of the
world.  Some don't get enough sun so they *can* be given a small
amount of the hormone to prevent rickets (the disease one gets when
one doesn't have enough "vitamin D"). 

The truth of the matter is that the only way to get "vitamin D" to do
the right things in our bodies is to make it from sunshine and the
amount of sunshine we need to do this is a mere 1 hour 3 times a week
on the cheeks.  Can we OD on it from sunshine?  No.

So in making sure you get enough calcium, I would strongly suggest
buying dairy products that are not fortified with "vitamin D" (that
is, if you buy them) and watch your calcium:magnesium ratio (2:1).

Sorry I couldn't help with the forms of calcium.
-- 

----------------------------------------------------------------------
Craig Silver	           Computer Science at Simon Fraser University
silver@sfu.ca (Internet)   Burnaby, B.C., Canada