A Day Without Vitamin D Is Like a Day Without Sunshine Written by Jill Hillhouse

Vitamin D has been best known for its role in preventing rickets and supporting calcium absorption for bone health but research over the past couple of years has uncovered more about the other roles Vitamin D has in the body specifically, in the H1N1 era, with regard to immunity.

A recent study about Vitamin D and immunity was published in the American Journal of Clinical Nutrition in March of 2010, and it demonstrates very exciting results. From December 2008 through March 2009, researchers conducted a randomized, double-blind, placebo-controlled trial (the gold standard in scientific testing) that compared Vitamin D-3 supplementation with a placebo in school children. They found that the children taking the Vitamin D supplementation had a 42% lower risk of catching the flu than the children taking the placebo. Additionally, asthma attacks in the children that had previously been diagnosed with asthma almost disappeared during the same time with the Vitamin D-3 supplementation.

But how does this all work? Another new study done at Copenhagen University shows us. The immune system has many components but the front line soldiers are called the T-cells. T cells work by either attacking and destroying all cells carrying traces of a foreign pathogen or by 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 the next encounter and launch a more efficient and enhanced immune response. The researchers discovered that the first stage of the crucial activation of the T-cells involves Vitamin D. "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, lead researcher. Without T-cell activation, our immune system is severely compromised. The implications of this study are profound, considering that almost half of the world’s population has lower than optimal levels of Vitamin D and 97 percent of Canadians are Vitamin D deficient at some point during the year.

What about getting Vitamin D from the sun? This is a natural option – if you live above 35 degrees latitude. The most southerly latitude in Canada is 43 degrees, found in southern Ontario and the southern tip of Nova Scotia. For those of us that live above 35 degrees latitude, the sun is only at the right altitude for making Vitamin D in the body from about April until early October. So we should get all the sun we can during that time right? Well, maybe, but while it is the UVB rays from the sun that launch the production of  Vitamin D in the body, these rays also cause sun burn and the related negative effects. Oh, and we can’t make Vitamin D if we wear sunscreen.

So what are we to do? Health Canada says people need 200 to 600 International Units (IU’s) per day and the Canadian Cancer Society has been recommending 1,000 IUs per day. The children in the Vitamin D study were given 1200 IU’s. Consider that the body will make about 20,000 IUs when exposed for about 20 to 30 minutes to midday sun in the summer. The best bet is to have your Vitamin D levels checked (a blood test no longer covered by OHIP) and then speak to a Trusted Advisor on your health care team about the best supplements and dosing for you.

References :

http://whfoods.org/genpage.php?tname=nutrient&dbid=110

Khalsa, Soram. The Vitamin D Revolution. Hay House Inc. 2009.

http://www.theglobeandmail.com/life/health/two-studies-hope-to-test-the-benefits-of-Vitamin-d-once-and-for-all/article1490123/103/

Marina Rode von Essen, Martin Kongsbak, Peter Schjerling, Klaus Olgaard, Niels Ødum, Carsten Geisler.  Vitamin D controls T cell antigen receptor signaling and activation of human T cells.Journal name: Nature ImmunologyVolume: 11, 07 March 2010; 344-349Pages: