The Sunshine Vitamin: Vitamin D

With summer underway, the increased daylight and warmer temperatures encourage us to go outside and turn our faces to the sun. Buried in our genetic makeup is the innate understanding that we need sunlight for survival and health, and lately more and more information is being published on just how important it is. Vitamin D was best known for supporting calcium in bone health but in a time when immunitiy has become such a primary concern, the other roles vitamin D has in the body specifically are getting more attention.

Vitamin D Supplementation

The most recent study about vitamin D and immunity was published in the American Journal of Clinical Nutrition on March 23, 2010, the results of which are very exciting. 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 supplementation had a 42% lower risk of catching the flu than the children taking the placebo. They also found that asthma attacks almost disappeared during the same time with vitamin D-3 supplementation in the children that had previously been diagnosed with the inflammatory disease.

Vitamin D Crucial For T-Cells

Another new study done at Copenhagen University explains how these results are possible. The immune system has many components but the front line soldiers of the system are called the T-cells and they lie dormant until they are activated to detect and kill infections from viruses and bacteria. The researchers discovered that the first stage of the crucial activation of the T-cells involves vitamin D. They found that when a T-cell is exposed to a virus or bacteria, it immediately extends a signaling device or ‘antenna’ which is actually a vitamin D receptor that will search for vitamin D in the blood. The T-cell must have vitamin D or its activation will stop. “If the T-cells cannot find enough vitamin D in the blood, they won’t even begin to mobilize”, says Dr. Geisler, the 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.

Supplement or Sun?

Getting adequate amounts of Vitamin D from exposure to the sun is a natural option – if you live above 35 degrees latitude. For those of us that don’t live above 35 degrees latitude, the sun is only at the right altitude for making vitamin D in the body from about May until early October. Keep in mind, your skin must be exposed directly to the sun, without the use of sunscreen. As well, the UVB rays from the sun that launch the production of vitamin D in the body, can also cause sunburns and other related negative effects.

Supplementation may be the best option for you. How much vitamin D should you take? Your best bet is to have your vitamin D levels checked and then speak to your health care team about the best options 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/