Re: Calcitriol, Dr. Nogode's Study update

[Susan Evans Garlinghouse <suendavid@worldnet.att.net>]

Heidi and Susan, you
> might enjoy reading it.  I will send you copies if you send me your snail mail
> address.

Thanks, I'll go find it in the Cal Poly archives.
> 
> Dr. Nagode was researching a theory he had that supplementing horses about
> four days before a 100 mile ride with calcitriol (really) would improve the
> efficiency of intestinal calcium transport

Yes, calcitriol does have a function of increasing calcium uptake from
the gut.  However, the stimulation for this effect is hypocalcemia, or
low plasma calcium, which stimulates parathyroid hormone to mobilize
calcium from storage depots AND stimulate the release of
25-hydroxycholecalciferol from the kidneys and it's conversion to its
active form, 1,25-dihydroxycholecalciferol, aka calcitriol.  However,
the specific action by which calcitriol works is by stimulating the
synthesis of a protein called calcium-binding protein.  In other words,
the mechanisms are all already there for more calcium uptake and
mobilization when it's needed, and all you have to do is feed
sufficient-not-excessive calcium in the diet and get outta the way. 
Injecting exogenous D3 would not only be illegal, but probably not
particularly effective in a practical sense, as proteins don't get
synthesized in a flash.  dr. Nogode's work is certainly valid and
warranted, but practically speaking, is probably only of academic
interest.


> I contacted Dr. Nagode today by phone at Ohio State University.  He was kind
> enough to spend some time with me talking about that research 

Kind, HA!  Asking a researcher to talk about his work is alot like
asking water to please flow downhill. Most people have to beg us to stop
talking. :-D

(Just kidding, of course, that was nice of him).


  He was not
> able to get further funding to continue his studies with horses.

Join the club.


> He still believes that too much calcium in the diet interferes with the
> adaptive mechanisms for dealing with calcium deficiency. 

Yup, me too.

Thanks for the follow-up, Debby.

Susan Garlinghouse