Scientists: Vitamin D crucial for immunity

Danish scientists have determined sufficient intake of vitamin D is vital for the killer T cells of the immune system to fend off serious infections. And these findings could prove useful in the fight against infectious diseases, as well as during the development of new vaccines.

T cells work by either attacking and destroying all cells carrying traces of a foreign pathogen or assisting the immune system in acquiring memory. The so-called helper cells send messages to the immune system, passing on knowledge about the pathogen so that the system can recognize and remember it at their next encounter and launch a more efficient and enhanced immune response.

"When a T cell is exposed to a foreign pathogen, it has an immediate biochemical reaction and 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," explains Professor Carsten Geisler of the University of Copenhagen.

Scientists have long known that vitamin D is important for calcium absorption and implicated in 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," Geisler says. 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 can be taken as a dietary supplement.

- see the press release from the University of Copenhagen
- read the study abstract in the journal Nature Immunology