Role of the Vitamin D Receptor in Maintaining the Intestinal

[mle_ii]

http://www.ncbi.nlm.nih.gov/sites/entre ... med_DocSum

Novel Role of the Vitamin D Receptor in Maintaining the Integrity of the Intestinal Mucosal Barrier.Kong J, Zhang Z, Musch MW, Ning G, Sun J, Hart J, Bissonnette M, Li YC.
Medicine, The University of Chicago, Chicago, Illinois, United States; Chicago, Illinois, United States.

Emerging evidence supports a pathological link between vitamin D deficiency and the risk of inflammatory bowel disease (IBD). To explore the mechanism we used the dextran sulfate sodium (DSS)-induced colitis model to investigate the role of the vitamin D receptor (VDR) in mucosal barrier homeostasis. While VDR(+/+) mice were mostly resistant to 2.5% DSS, VDR(-/-) mice developed severe diarrhea, rectal bleeding and marked body weight loss, leading to death in 2 weeks. Histological examination revealed extensive ulceration and impaired wound healing in the colonic epithelium of DSS-treated VDR(-/-) mice. Severe ulceration in VDR(-/-) mice was preceded by a greater loss of intestinal transepithelial electric resistance (TER) compared to VDR(+/+) mice. Confocal and electron microscopy revealed severe disruption in epithelial junctions in VDR(-/-) mice after 3-day DSS treatment. Therefore, VDR(-/-) mice were much more susceptible to DSS-induced mucosal injury than VDR(+/+) mice. In cell cultures, 1,25(OH)2D3 markedly enhanced tight junctions formed by Caco-2 monolayers by increasing junction protein expression and TER and preserved the structural integrity of tight junctions in the presence of DSS. VDR knockdown with siRNA reduced the junction proteins and TER in Caco-2 monolayers. 1,25(OH)2D3 can also stimulate epithelial cell migration in vitro. These observations suggest that VDR plays a critical role in mucosal barrier homeostasis by preserving the integrity of junction complexes and the healing capacity of the colonic epithelium. Therefore, vitamin D-deficiency may compromise the mucosal barrier, leading to increased susceptibility to mucosal damage and increased risk of IBD. Key words: vitamin D receptor, intestinal mucosal barrier, inflammatory bowel disease, tight junction, vitamin D.

[tex]

Well I'll be a monkey's uncle - that's some downright profound information, isn't it. That probably explains why Canada has such a high rate of Crohn's disease.

So does that suggest that high doses of vitamin D should be beneficial to MCers, and anyone else with an IBD, or am reading too much into this?

Tex

[mle_ii]

Not sure I can go that far yet. But it would mean that it would be a good idea to have Vitamin D be on a normal blood test panel. And that if one were low should supplement.

Perhaps a high dose would be good, but I would say this with caution as though it's called a Vitamin, it is as we can see here and in various other studies, pretty damn powerful stuff. It could cause problems with calcium balance if one does not watch out.

But as you pointed out this is pretty profound.

[harvest_table]

Hmmm, that's very interesting. Thanks Mike.


Love,
Joanna

[Gloria]

This is very interesting. Since one can get vitamin D from sunlight, it would be interesting to see if people with outside jobs have less incidence of MC.

[mle_ii]

This is very interesting. Since one can get vitamin D from sunlight, it would be interesting to see if people with outside jobs have less incidence of MC.

My guess would be yes, but there might be other reasons for them to have less incidence of MC. Like say outside jobs more likely in being physical labor rather than a desk type job. Perhaps more oxygen, less recycled air, less RF radiation, and other reasons. So unless they could rule those things out they couldn't say for sure. But I'd lean towards more sunlight and more Vitamin D increasing the chance of not having MC.

[mle_ii]

Here's an article about this study from Celiac.com:
http://www.celiac.com/articles/21476/1/ ... Page1.html