Re: Vitamin D Question

Comments are at the bottom. I don't quite
fully answer the question but I note some points that
I think are related.

"John" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> Maybe someone can give me some help here. I got my latest
> blood test results back and while the calcium levels remain
> very good at 9.2 ( range is 8.5 to 10.5 ), my Vitamin D
> level has me perplexed. It is 14 where the normal range is
> 10 to 68. I realize that it is in the Lo-normal range but i
> am wondering what happens to all the vitamin d in my system.
>
> Am i excreting the excess? IS there any excess to excrete?
> I  take a good multi=vitamin that includes 400 u.i of Vit D
> daily as well as another 400 u.i in my citrical tablets. I
> am also out in the sun - albeit a lot less with the onset of
> winter.
>
> I will be seeing two endocrinologists as well as my other
> treating physicians in the next few weeks and i will let the
> group know what statements they give me.
>
> Sincerely
> --
> John
> moderator sci.med.diseases.osteoporosis.newsgroup
> http://www.jmadura.com/osteofaq.htm
>

The body maintains calcium serum levels within rather
strict bounds. It will rob the bone if new calcium coming
from dietary sources is insufficient or if absorption is
inadequate.

You seem to think 400 IU of vitamin D is adequate, it
isn't. If some so-called expert says this is so, they don't know
what they are talkiing about. It has long been know that
a person living in the tropics gets far higher levels of
vitamin D from synthesis due sunlight in the area of
4000 IUs per day. Ten times 400!!!
Since you are low in vitamin D you aren't getting enough
sun. Aging, sunscreen, and frequent bathing reduces
vitamin D synthesis at the skin, as I recall.
More recent research has shown
low level supplementations with 400 IU (10 mcgs)
of vitamin D to often fails to increase subject status
to what is consider an adequate level.
Even the quite conservative Food and Nutrition Board
of the Institute of Medicine has set the tolerable upper
limit at 2000 IUs for CHILDREN, adults, pregnant and
lactating women. So it is clear 1000 IU isn't going to hurt.
During WINTER MONTHS, I've chosen to
take 4000 IUs of vitamin D3. And yes that is twice
the UL.  Clearly I think the actual real world UL is
higher. I wouldn't do that with vitamin
D2 as this form of D is found only at rather low
levels when compared to D3 in nature. If you
are conservative, I'll suggest the supplement dose size of
800 IU is a bare minamum and 1000 IUs
a tad more reasonable in the context of the
use of other supplements for YEAR
AROUND USE.

Please recall that corticosteroids are said to impair
vitamin D metabolism. Moreover, corticosteroids reduces
calcium absorption.

Your other question as to the fate of vitamin D in the
body is an interesting one. Vitamin D doesn't seem to
have as long a potential storage life a vitamin A, albeit
a longer than vitamin K and E. By the way E biological
half life is rather short.....think days.  I am running on
memory in the previous two sentences.

Now back to your question, there was a recent report of a
study in which the subjects took one 100,000 IUs vitamin
D3  dose every three months. Which averages to 800 IUs
per day. Albeit the researcher's bottom line recommend was
quite cowardly IMO as he recommended vitamin D
in the range of 400 to 800 per day. His subject
taking the vitamin D showed a marked decrease
in fractures. Kay Tee Khaw was lead researcher.
There is evidence that 400 IU per day supplements are too
small. And remember he used an average of 800 IUs
per day plus a calcium supplement of 1200 mgs.

Recall, that vitamin D is regulated by activation of
the "vitamin"  form into various active forms.
First, the vitamin is modified by
the liver into 25-(OH)D. This form is
still not an active form but is just an inactive
substrate. However, the levels of 25-(OH)D found in tests
do provide a good measure of vitamin D status.
Renal synthesis of 1,25-(OH)2D is quite tightly controlled.
This active form regulates bone mineral homeostasis
by a number of avenues. Intestinal epithelial cells
have a receptor type to which the active
form binds. This stimulation combined with retinoid
action on another receptor results in the production
of calbindin a calcium binding protein the
with plays a role in pump Ca++ out of cells.
The active form effects the microvilli so as to increase the
permeability of calcium ions thru their membranes.
It thus helps getting Ca++ in from intestinal lumen.
In the bone, the osteoprogenitor
cells and mature osteoblasts all contain 1,25-(OH)2D
receptors. Their activation by the activated vitamin D
 results in the differentiation of these cells.
Here the actions get fairly complicated.
There is an involvement with bone reabsorption,
lysomal enzyme release, and reduced collagen synthesis in
the bone according to in vitro research.
In the kidney this active form has actions like
those in the intestine that serve to promote the recovery
of Ca++ from the dilute out going liquid.
Futher it must emphasized that the activated form of  D
regulates growth and differentiation many
tissue cells. In other words, it plays a role in the
prevention of skin, prostate, and breast cancer!!!
It plays a role in the regulation of PTH.
It is involved in insulin secretion.
And the immune system are in part modulated
by 1,25-(OH)2 D. In test animals it served to
both increase protective responses to infection
and suppresses autoimmune damage. There is
still much research needing to be done
in humans. The lack of fully developed research
reflects a full blown failure on the part
our science system, IMO.

In a related topic, it is my opinion
a person should be taking
a vitamin K supplement that is above
1 milligram per day and not some silly little 100 microgram
dose. Or at the very least choosing eat
greens cooked with a modest amount
of oil or fat to enhance vitamin K.
Note also that vitamin K helps to prevent soft tissue
calcinosis/calcification. Calcinosis is the lasting
damage that huge doses of vitamin D has caused.
Remember vitamin K is as important as D to
bone health!

I suggest you do a Google search of some
of the other Newsgroup forums such as
sci.med.nutrition, sci.med, sci.life-extension on the
topic of vitamin D.

I left loads out and there are points I am unclear
on myself. I'll suggest since you are the moderator
that you start a hard copy notebooks a
number of common bone metabolism issues
such as vitamin D, vitamin K, calcium,
other minerals, the various forms of hormone
replacement therapies used in men and
women, common aging changes
that makes persons prone to osteopenia
and osteoporosis, alternative remedies and
ideas, and current standard medical protocols.
What is that 10 notebooks? That is a bit much.
And yet even I a would be denizen of the
life-extension forum has that many
computer sub-directors dedicated to these topics.
Some selective cross-posting maybe
in order so all in THIS forum get to
see the better responses from the other groups. If you
can bump out the trolls it would be nice.

Warning!! I do not claim to be a medical professional......
This is serious. Trust but verify.....better...'Verify then trust'

Finally I'll try to provide references if you require it
on a specific point.

William A. Noyes