Tuesday, September 8, 2009

Seasonal Immunity

Labor Day has passed. Students should all be back to school now. The days are getting shorter. The leaves are beginning to change color. It is time to think about how to forestall illness.

Wow. What a downer, associating Autumn with illness; but, unfortunately, that’s the way it is. What’s the connection? Sunshine, or the lack thereof. More specifically, it is the reduction of UVB radiation striking the Earth as its angle relative to the Sun limits our exposure.

Now, what does reduced exposure to UVB radiation have to do with increased levels of illness? Isn’t UVB radiation a bad thing? As regular readers of my blog and newsletter know, no, UVB radiation is actually necessary to maintaining good health.

The cells of your immune system contain Vitamin D Receptors (VDR). This means that the optimal functioning of your immune system requires optimal levels of vitamin D in your blood. If your immune system is not optimized, you are more likely to become ill. Viruses and other pathogens will have relatively free rein in your body because your defense system is sub-par.

Unprotected skin exposed to UVB radiation activates the vitamin D system, increasing blood levels of vitamin D. However, numerous factors inhibit this natural system including: over-protection of the skin (see my blog “Dermatological Purdah”); dark pigmentation at high latitudes; old age; and life spent indoors. Current estimates are that the majority of Americans have sub-optimal levels of vitamin D and are, therefore, at high risk for having a sub-optimal immune system.

If Americans aren’t getting enough vitamin D the natural way, then they will have to use supplementation. The current US recommended levels are much too low to optimize vitamin D levels. Dr. Cannell, physician and vitamin D researcher living in California, recommends that children receive 1000 IU of vitamin D3/day for each 25 lbs of weight. He takes 5000 IU/day during the winter months. The minimum recommended dose for adults, according the Canadian Cancer Society, is 1000 IU/day, year-round. Dr. Vieth, Canadian vitamin D researcher, recommends a minimum daily dose of 4000 IU/day during the winter months.

As a child, teen, and young adult, I caught pretty much every pathogen that passed by me. It wasn’t until years later, when I began my research on vitamin D, that I realized that I suffered from sub-optimal levels of vitamin D. My two big fixes for the problem were to eat sardines every day and to move to Arizona. While this did work, after several years I ended up moving back to the Midwest to be near my family. The move resulted in having to tinker some with vitamin D supplementation to achieve optimization. What appears to work for me is this: every day I eat a can of sardines. In addition to providing several hundred IU/day of vitamin D, I also get a good dose of omega-3 fatty acids, calcium, and protein. However, in the Midwest, sardines do not provide enough vitamin D. Therefore, during the summer months, I take 2000 IU/day of vitamin D3. [I just do not get out enough in the sun during the summer to optimize my vitamin D levels naturally.] In the autumn, I increase this to 3000 IU/day, then to 4000 IU/day, and finally, during the depths of winter, to 5000 IU/day. While this does not prevent every cold, I am far, far healthier than I was during my previous sojourn in the Midwest.

While this dosing schedule works for me, you will need to develop one individualized for your own set of variables. Also, if you are on any medications, you will need to discuss it with your physician. Do not wait until the leaves have all fallen to begin optimizing your vitamin D levels. It takes a few weeks to achieve optimization. If you want to have the best chance to avoid the season of colds and flu, you need to begin now. Here’s To Your Health!

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