Vitamin D crucial to activating immune defenses

University of Copenhagen ^ | Mar 7, 2010 | Unknown

[decimon]

Vitamin D Crucial To Activating Immune Defenses

Scientists at the University of Copenhagen have discovered that Vitamin D is crucial to activating our immune defenses and that without sufficient intake of the vitamin, the killer cells of the immune system – T cells - will not be able to react to and fight off serious infections in the body.

For T cells to detect and kill foreign pathogens such as clumps of bacteria or viruses, the cells must first be 'triggered' into action and 'transform' from inactive and harmless immune cells into killer cells that are primed to seek out and destroy all traces of a foreign pathogen.

The researchers found that the T cells rely on vitamin D in order to activate and they would remain dormant, 'naïve' to the possibility of threat if vitamin D is lacking in the blood.

Chemical Reaction that Enables Activation

In order for the specialized immune cells (T cells) to protect the body from dangerous viruses or bacteria, the T cells must first be exposed to traces of the foreign pathogen. This occurs when they are presented by other immune cells in the body (known as macrophages) with suspicious 'cell fragments' or 'traces' of the pathogen. The T cells then bind to the fragment and divide and multiply into hundreds of identical cells that are all focused on the same pathogen type. The sequence of chemical changes that the T cells undergo enables them to both be 'sensitized to' and able to deliver a targeted immune response.

Professor Carsten Geisler from the Department of International Health, Immunology and Microbiology explains that "when a T cell is exposed to a foreign pathogen, it extends a signaling device or 'antenna' known as a vitamin D receptor, with which it searches for vitamin D. This means that the T cell must have vitamin D or activation of the cell will cease. If the T cells cannot find enough vitamin D in the blood, they won't even begin to mobilize. "

T cells that are successfully activated transform into one of two types of immune cell. They either become killer cells that will attack and destroy all cells carrying traces of a foreign pathogen or they become helper cells that assist the immune system in acquiring "memory". The helper cells send messages to the immune system, passing on knowledge about the pathogen so that the immune system can recognize and remember it at their next encounter. T cells form part of the adaptive immune system, which means that they function by teaching the immune system to recognize and adapt to constantly changing threats.

Activating and Deactivating the Immune System

For the research team, identifying the role of vitamin D in the activation of T cells has been a major breakthrough. "Scientists have known for a long time that vitamin D is important for calcium absorption and the vitamin has also been implicated in diseases such as cancer and multiple sclerosis, but what we didn't realize is how crucial vitamin D is for actually activating the immune system – which we know now. "

The discovery, the scientists believe, provides much needed information about the immune system and will help them regulate the immune response. This is important not only in fighting disease but also in dealing with anti-immune reactions of the body and the rejection of transplanted organs. Active T cells multiply at an explosive rate and can create an inflammatory environment with serious consequences for the body. After organ transplants, e.g. T cells can attack the donor organ as a "foreign invader". In autoimmune disease, hypersensitive T cells mistake fragments of the body's own cells for foreign pathogens, leading to the body launching an attack upon itself.

The research team was also able to track the biochemical sequence of the transformation of an inactive T cell to an active cell, and thus would be able to intervene at several points to modulate the immune response. Inactive or 'naïve' T cells crucially contain neither the vitamin D receptor nor a specific molecule (PLC-gamma1) that would enable the cell to deliver an antigen specific response.

The findings, continues Professor Geisler "could help us to combat infectious diseases and global epidemics. They will be of particular use when developing new vaccines, which work precisely on the basis of both training our immune systems to react and suppressing the body's natural defenses in situations where this is important – as is the case with organ transplants and autoimmune disease."

Most Vitamin D is produced as a natural byproduct of the skin's exposure to sunlight. It can also be found in fish liver oil, eggs and fatty fish such as salmon, herring and mackerel or taken as a dietary supplement. No definitive studies have been carried out for the optimal daily dosage of vitamin D but as a large proportion of the population have very low concentrations of vitamin D in the blood, a number of experts recommend between 25-50mg micrograms a day.

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The findings will be published in the latest edition of Nature Immunology, (Vitamin D controls T cell antigen receptor signaling and activation of human T cells ) 10.1038/ni.1851, on 07 March 1800 London Time/1300 Us Eastern Time.

Press coverage of the release is embargoed until this date and time.

Contact Details

Professor and Head of Department, Carsten Geisler Tel: (+45) 35 32 78 80 Mobile: (+45) 28 75 7880 Email: cge@sund.ku.dk Department of International Health, Immunology and Microbiology Faculty of Health Sciences University of Copenhagen´

Press Officer, Sandra Szivos Tel: (+45) 35 32 69 21 Mobile: (+45) 28 75 69 21 Email: sasz@sund.ku.dk

Press Officer, Anne Dorte Bach Tel: (+45) 35 32 42 63 Email: adba@adm.ku.dk

[decimon]

Model of the Findings: Naïve T Cells Do not Express Vitamin D Receptor nor Plc-Gamma1

Caption: When the naïve T cell recognizes foreign molecules with its T cell receptor (TCR) it sends activation signals (1) to the VDR gene. The VDR gene now starts the production of VDR (2). VDR binds vitamin D in the T cell (3) and becomes activated. Vitamin D bound to activated VDR goes back into the cell nucleus and activates the gene for PLC-gamma1 (5). PLC-gamma1 is produced (6) and the T cells can get started.

Credit: Professor of Immunology, Carsten Geisler

Usage Restrictions: This image and all other graphic or textual content related to the press release is embargoed until March 7, 1800 London Time, 1300 US Eastern Standard Time

Related news release: Vitamin D crucial to activating immune defenses

[decimon]

D Dane defense ping.

[TypeZoNegative]

Libs have made it “uncool” for children to play outside, so look out for an upward trend in colds, flus and other infectious diseases.

[James C. Bennett]

Question is, is food-additive Vit D as effective as skin-produced Vit D?

[MozarkDawg]

Most Vitamin D is produced as a natural byproduct of the skin's exposure to sunlight.

All the scare stuff over skin cancer, people have been slathering on the sunscreen to the detriment of Vitamin D absorption -- an endocrinologist told me several years ago, ten minutes a day out in the fresh air and sunshine is sufficient to proper D absorption and will not be enough to endanger one or damage skin.

Get outside, people.

[MozarkDawg]

Question is, is food-additive Vit D as effective as skin-produced Vit D?

Apparently, as the nationwide deficiency causing rickets was what led to Vitamin D fortifying butter and milk decades ago, my understanding is that the cases dropped exponentially afterward.

[decimon]

Question is, is food-additive Vit D as effective as skin-produced Vit D?

Good question that I don't think I've seen answered directly. But I've seen nothing to say that supplemental vitamin D doesn't work.

There is one thing - adding vitamin D to foods did apparently do away with the formerly common rickets.

[Harmless Teddy Bear]

an endocrinologist told me several years ago, ten minutes a day out in the fresh air and sunshine is sufficient to proper D absorption

He was wrong unless you live south of 42 degrees latitude. You also need to be wearing shorts and a tank top for that to be enough time.

If you live north of 42 degrees latitude then you will get almost no vitamin D from the sun from November through February. Depending on where you are you might not even see the sun for days and wearing shorts and a tank top during those times the sun does decide to peak out is usually impractical.

[waus]

Mercola has an entire section devoted to vitamin D information:

http://vitamind.mercola.com/

[waus]

Exactly...sunscreen actually increases your cancer risk:

http://articles.mercola.com/sites/articles/archive/2003/07/02/sunblock-cancer-part-one.aspx

[bgill]

I’ve increased my Vit D supplements because of all the flu scare. There is a nasty bug going on here. Kid brought it home from school but it wasn’t too bad which may be because he’s outside often. Hubby, who doesn’t go outside, caught it and was in bad shape for a week. Then, I caught it but was over it in three days. Usually, I’m the one who is laid up with a chest infection at the least hint of a bug.

[denydenydeny]

It should have been the most obvious thing in the world.

For the longest time knew two salient facts seemingly at odds with each other:

A) Colds and flu are not caused by outside temperature but by microbes.

B) And yet there is a “cold and flu season” which occurs exclusively in the colder months of the year.

It was a logical paradox that the medical community seemed to shrug their shoulders over. Scientists are not supposed to be Walter Cronkite: “That’s the way it is” is not a sufficient explanation for anything. There had to be a reason.

Why I think it took so long for them to come to the conclusion was the medical and scientific community’s reluctance to look for nutritional solutions for any disease. But the conclusion is inescapable: We are out in the sun far less during the colder months, and the sun is less intense in those months, and the reduced amounts of Vitamin D make all the difference in whether we get sick or not. It’s so simple it should have been obvious all along.

[DvdMom]

Smokin’ Joe I pinged your list and some other freepers to a new different Vitamin D Article ...

thanks freepers decimon & freeper Smokin’ Joe :)

[denydenydeny]

To amend what I said: the sun’s light is always the same, the sunlight reaching the northern latitudes is less intense in the winter months.

[Alamo-Girl]

Thanks for the ping!

[Battle Axe]

When did they put Vit D into milk and butter? Folks on the farm would still be drinking their own cow's milk and making their own butter and thus not get the benefits.

[A CA Guy]

D3 in particular.

[GrannyAnn]

***We are out in the sun far less during the colder months, and the sun is less intense in those months, and the reduced amounts of Vitamin D make all the difference in whether we get sick or not. It’s so simple it should have been obvious all along.***

You make a good point here. This is just an anecdotal observation but my husband golfs year round here in AZ and is rarely sick. He never seems to catch what I get either.

[GrannyAnn]

They now put huge shade coverings over the school jungle gyms here in AZ. For years we played outside in the sun, now the kids have to play in shade. Stupid libs.

[luckystarmom]

We’ve been supplementing with vitamin D this year, and my daughter has had the worst colds this year. She’s had 2 that have gone in to secondary infections and needed anti-biotics.

She was low on vitamin D last year, and she’ll get retested soon.