TSH way down/No symptomatic relief

[Guest guest]

Crystal,

You wrote:

>

> I truly believe the calcitonin in Armour is very beneficial!

Your belief is not particularly well founded in science. Calcitonin is

not just made in the thyroid, but in many organs, including lungs and

intestines. Although calcitonin has been shown to play an important role

in calcium concentration control in animals, tests in humans have show

much less of an effect. In fact, to have a therapeutic effect (e.g. for

treating Paget's disease), you need 100-400 IU, depending on the source.

Salmon calcitonin is more potent than human.

Forest Pharmaceuticals does not control Armour for calcitonin content.

That means that one dose could contain zero; the next day might be

closer to 1 IU. Not exactly a dependable nor a substantive source.

Finally, the stuff has a very short life in the body, about an hour and

a half. So, the steady supply you get from your own organs is probably

much more effective than the brief and minor pulse you get by taking

Armour.

There is hardly any justification in any of these facts for taking

Armour rather than a T4. If you really feel you need more calcitonin

than your body will produce naturally, each more salmon.

Here's a summary from the Endocrine Index at Colorado State:

http://www.vivo.colostate.edu/hbooks/pathphys/endocrine/thyroid/calcitonin.html

" Calcitonin is a hormone known to participate in calcium and phosphorus

metabolism. In mammals, the major source of calcitonin is from the

parafollicular or C cells in the thyroid gland, but it is also

synthesized in a wide variety of other tissues, including the lung and

intestinal tract. In birds, fish and amphibians, calcitonin is secreted

from the ultimobrachial glands.

Calcitonin is a 32 amino acid peptide cleaved from a larger prohormone.

It contains a single disulfide bond, which causes the amino terminus to

assume the shape of a ring. Alternative splicing of the calcitonin

pre-mRNA can yield a mRNA encoding calcitonin gene-related peptide; that

peptide appears to function in the nervous and vascular systems. The

calcitonin receptor has been cloned and shown to be a member of the

seven-transmembrane, G protein-coupled receptor family.

Physiologic Effects of Calcitonin

A large and diverse set of effects has been attributed to calcitonin,

but in many cases, these were seen in response to pharmacologic doses of

the hormone, and their physiologic relevance is suspect. It seems clear

however, that calcitonin plays a role in calcium and phosphorus

metabolism. In particular, calcitonin has the ability to decrease blood

calcium levels at least in part by effects on two well-studied target

organs:

* Bone: Calcitonin suppresses resorption of bone by inhibiting the

activity of osteoclasts, a cell type that " digests " bone matrix,

releasing calcium and phosphorus into blood.

* Kidney: Calcium and phosphorus are prevented from being lost in

urine by reabsorption in the kidney tubules. Calcitonin inhibits tubular

reabsorption of these two ions, leading to increased rates of their loss

in urine.

It seems clear that there are species differences in the importance of

calcitonin as a factor affecting calcium homeostasis. In fish, rodents

and some domestic animals, calcitonin appears to play a significant role

in calcium homeostais. In humans, calcitonin has at best a minor role in

regulating blood concentrations of calcium. One interesting piece of

evidence to support this statement is that humans with chronically

increased (medullary thyroid cancer) or decreased (surgical removal of

the thyroid gland) levels of calcitonin in blood usually do not show

alterations from normal in serum calcium concentration.

Chuck