Troubling Vit D research - What are we to think???

[Guest guest]

Normally, I'm very skeptical of research proporting to find supplements are

" dangerous. "

But this seems different to me; after all, oral supplementation of vit d - no

matter how

bioidentical - is not at all the way nature/the body goes about getting vitamin

d.

I'd love to know what others think about this and whether they will discontinue

any Vit D

sups until it's sorted out.

http://www.sciencedaily.com/releases/2008/01/080125223302.htm

VitaminD Deficiency Study Raises New Questions About Disease And Supplements

ScienceDaily (Jan. 27, 2008) — Low blood levels of vitaminD have long

been associated with disease, and the assumption has been that vitamin

D supplements may protect against disease. However, this new research

demonstrates that ingested vitaminD is immunosuppressive and that low

blood levels of vitaminD may be actually a result of the disease

process. Supplementation may make the disease worse.

In a new report Trevor Marshall, Ph.D., professor at Australia's

Murdoch University School of Biological Medicine and Biotechnology,

explains how increased vitaminD intake affects much more than just

nutrition or bone health. The paper explains how the VitaminD Nuclear

Receptor (VDR) acts in the repression or transcription of hundreds of

genes, including genes associated with diseases ranging from cancers

to multiple sclerosis.

" The VDR is at the heart of innate immunity, being responsible for

expression of most of the antimicrobial peptides, which are the body's

ultimate response to infection, " Marshall said.

" Molecular biology is now forcing us to re-think the idea that a low

measured value of vitaminD means we simply must add more to our diet.

Supplemental vitaminD has been used for decades, and yet the

epidemics of chronic disease, such as heart disease and obesity, are

just getting worse. "

" Our disease model has shown us why low levels of vitaminD are

observed in association with major and chronic illness, " Marshall

added. " VitaminD is a secosteroid hormone, and the body regulates the

production of all it needs. In fact, the use of supplements can be

harmful, because they suppress the immune system so that the body

cannot fight disease and infection effectively. "

Marshall's research has demonstrated how ingested vitaminD can

actually block VDR activation, the opposite effect to that of

Sunshine. Instead of a positive effect on gene expression, Marshall

reported that his own work, as well as the work of others, shows that

quite nominal doses of ingested vitaminD can suppress the proper

operation of the immune system. It is a different metabolite, a

secosteroid hormone called 1,25-dihydroxyvitamin D, which activates

the VDR to regulate the expression of the genes. Under conditions that

exist in infection or inflammation, the body automatically regulates

its production of all the vitaminD metabolites, including

25-hydroxyvitamin D, the metabolite which is usually measured to

indicate vitaminD status.

VitaminD deficiency, long interpreted as a cause of disease, is more

likely the result of the disease process, and increasing intake of

vitaminD often makes the disease worse. " Dysregulation of vitaminD

has been observed in many chronic diseases, including many thought to

be autoimmune, " said J.C. Waterhouse, Ph.D., lead author of a book

chapter on vitaminD and chronic disease.

" We have found that vitaminD supplementation, even at levels many

consider desirable, interferes with recovery in these patients. "

" We need to discard the notion that vitaminD affects a disease state

in a simple way, " Marshall said. " VitaminD affects the expression of

over 1,000 genes, so we should not expect a simplistic cause and

effect between vitaminD supplementation and disease. The

comprehensive studies are just not showing that supplementary vitamin

D makes people healthier. "

Journal reference: Marshall TG. VitaminD discovery outpaces FDA

decision making. Bioessays. 2008 Jan 15;30(2):173-182 [Epub ahead of

print] Online ISSN: 1521-1878 Print ISSN: 0265-9247 PMID: 18200565

Adapted from materials provided by Autoimmunity Research Foundation,

via AlphaGalileo.