You may have heard of Mr. T. He’s a fictional character from The A-Team, but I’m talking about another Mr. T—T cells. T cells are part of the adaptive immune system. That means that they function by teaching the immune system to recognize and adapt to constantly changing threats.
T cells are white blood cells that can transform into two types of cells—at least once they’re activated. One type searches and destroys infectious agents, while the other type records information about the invading pathogen and communicates that knowledge to other parts of the immune system. That’s why the latter cells are called “helper” cells; they help the immune system respond quickly if there is a future infection with a similar invader.
The key here is that these T cells must be activated in order to function properly. If they’re not activated, then they just sit there—with no immune response—and those invaders can march right on in and gain a foothold.
So what activates these killer T cells? Vitamin D.
You heard right. Scientists have known for some time now that vitamin D supports bone health and much more, but until recently, they’ve not known that vitamin D supports the immune system—and, in particular, serves to activate T cells so they can fight off viral and bacterial invaders.
In fact, researchers from the University of Copenhagen found that T cells rely on vitamin D in order to activate and that they remain dormant, “naïve” to the possibility of threat if vitamin D is lacking in the blood. In short, if there’s not enough vitamin D in the blood, then the T cells remain passive and no immune response occurs. Their study was published in the journal Nature Immunology.
Professor Carsten Geisler, of the Department of International Health, Immunology and Microbiology, explains further 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 (white blood cells) cannot find enough vitamin D in the blood, they won’t even begin to mobilize.”
And that could spell trouble—especially since 75% of U.S. teens and adults are deficient in vitamin D.
Make sure your T cells are activated this season. Introduce Mr. T to Mr. D—vitamin D, that is. Together, they make a pretty amazing A-Team of their own, especially when it comes to a healthy immune system.