Food just isn’t as nutritious as it used to be, mainly because over-farming practices have robbed the soil of its nutrition. Fruits and vegetables are less nutrient dense than they used to be, and we are consuming fewer of them on average due to the prevalence of highly processed, readily available foods that are prepackaged and take no prep time (hey, we’re all busy!).
So, you might be swallowing a multi-vitamin or even a combination of supplements to boost your nutritional intake and get all the nutrients you need. One of the most commonly recommended vitamins of late is Vitamin D due to its powerful ability to boost immune system function and help fight disease.
When the body identifies a foreign invader, the T-cell (immune system cells) send out a Vitamin D receptor that actually activates their function and allows them to fight off the pathogen. Researchers have long known that Vitamin D is imperative for calcium absorption, but they had no idea how critical it was for keeping the immune system healthy and functioning.
Vitamin D can be found in foods like fish liver oil, egg yolks and fatty fish such as salmon, herring and mackerel, but the best source of Vitamin D is that which your body absorbs from sunlight (without burning, of course!). Of course, in northern latitudes (hello, Seattle) we don’t get quite so much sun in the winter, which has been linked to higher incidence of multiple sclerosis and other auto-immune diseases.
Suddenly, it makes a lot more sense as to why Nordic cultures rely so heavily on deep water fatty fish as their primary food source….
Enter Vitamin D supplementation! But buyer beware, all Vitamin D is not created equal. There are two forms of Vitamin D – D2 (ergocalciferol) and D3 (cholecalciferol). Vitamin D2 is usually available in prescription form while D3 is available over the counter at relatively low cost (around $6-9 per bottle).
Vitamin D3 is what is produced naturally in our bodies when our skin is exposed to sunlight. D2 is made by irradiating plant matter and fungus. A compilation of 42 studies involving Vitamin D showed that Vitamin D2 is correlated with a 2% increase in mortality while Vitamin D3 is correlated with a 6% reduction in death.
The bottom line is that you should supplement with Vitamin D3, the same form that is naturally produced inside your body when skin is safely exposed to sunlight. You can also use cold water fish oil, such as cod liver oil, to supplement. If you are in northern climates, you almost certainly need Vitamin D supplementation in the winter, although your naturopath or physician can run a blood test to see if you are deficient.