You may have noticed this subject of Vitamin D ("D") showing up more often these days, especially if you are living north of the 39th parallel. D's role in your basic health is well documented, but lately more information is appearing on its impact on your daily life.
Historically it was known that D, in combination with calcium, promoted strong bones and as we age we need to increase our D intake. However in the last few years, we now realize D does much more. Proper levels of D have now been connected to the reduced risk of various forms of cancer, heart disease, and MS.
Interestingly, D is not technically a vitamin. To quote the Vitamin D council,
"Technically not a "vitamin," vitamin D is in a class by itself. Its metabolic product, calcitriol, is actually a secosteroid hormone that is the key that unlocks binding sites on the human genome. The human genome contains more than 2,700 binding sites for calcitriol; those binding sites are near genes involved in virtually every known major disease of humans."
The more you dig, the more you realize just how important D really is!
The most recent findings and most interesting part when it comes to athletes is D's role in activating our immune system. Essentially, our body needs a certain level of D to activate T-cells. This is a critical function of our immune system. Our immune system can't function optimally if there's not enough D available. It does not affect the production of T-Cells but affects their mobility and memory. Think of having a huge army at your disposal but not enough trucks to move them, even worse the ability to tell them what to do!
As athletes we really give our immune system a workout. This is why athletes actually tend to get sick more often! Especially if we are over training and not getting enough rest. This becomes even more of a factor when we bring our training indoors, or at the Crossfit studio as we handle equipment that has been handled by others, kick up dust during our workouts and leave and transfer sweat.
Recently, Dr Michael Colgan, a BC native based on Saltspring Island, of the Colgan Institute of Canada, released a study that discusses the subject of D and sunscreen. It's a brilliant read so I have attached it to this post. His article could be considered somewhat controversial if you are a sun screen company. The article is very detailed but to summarize one of the key point; if you need sun exposure to get D, and you're wearing sunscreen all day, how do you get enough UV? You will be protecting your skin but will you be getting the dose of UV you need to get your D? What are the broader health consequences to sub optimal D levels ? He outlines several risks of sub optimal D levels.
The bottom line: if you are north of the 39th parallel, you NEED to supplement your D.
The UV levels in our northern sun exposure are not generating the D levels we need. If your levels are very low, your athletic performance and your immune system will be affected. As athletes we affect on our immune system every day, and now with the link between D and our immune system established, you're just asking for trouble if you do not monitor your levels and make an effort to keep you D in the green.
If you want to find out more about you D levels and how to supplement, I will be continuing the subject in future posts. I also have D kits for testing your level. Stop in if you want to find out more!
For more information, have a look at some of these articles:
Look who is taking D these days:
D's Role in our Immune System:
Vitamin D and Living north of the 39th Parallel