What is it?
Vitamin D has become a well known and widely recommended vitamin and supplement. Many people relate its name to the sun and to bone health. I have come across many people (patients included) who supplement their diets with this. But did you know that it plays an important role in the immune system’s health? Let’s explore just another of the many functions of vitamin D.
This vitamin is one of four fat soluble vitamins (along with vitamins A, E, and K). They are present in foods that contain fat – my food recommendations to obtain it will come later in this article. In order for the body to properly absorb and utilize it, it must be consumed with fat. Most people know that your body can synthesize vitamin D with proper sun exposure. This means exposing your skin and eyes to the sun daily without sunscreens or sunglasses. The absolute best way to get this vitamin is from the sun.
Why do we vitamin D?
It is now becoming clear that it has important roles when it comes to immunity. Research provides evidence that immune cells are host to receptor sites specific to it. Amazing observations of this active vitamin in these sites have taught us that it modulates the innate and adaptive immune system (the two components of immunology). Deficiency in this is associated with increased autoimmunity as well as an increased susceptibility to infection.
Perhaps even more relevant considering today’s front page news (covid-19), this vitamin is linked to lung health! A study carried out at the University of Western Australia, the Busselton Health Study and Sir Charles Gairdner Hospital has found vitamin D deficiency can contribute to poor respiratory function and health in middle-aged adults. The investigators found that low lung function directly correlated to deficiency.
What does this mean for those of us who are not cell biologists? It means that it’s not only critical for bone and joint health. Therefore it is necessary for robust and proper immune system function AND lung function.
Does that mean you should run out and buy a vitamin D supplement?
Not exactly. In fact, taking a supplement for anything that your body naturally synthesizes actually interrupts your body’s natural ability to make it for you! Supplementing with the vitamin should never be a long term solution to ensuring that you have appropriate amounts for optimal health.
Well then, what are the best sources of vitamin D so our bodies are supported and not enabled?
First and foremost, direct sun exposure! The sun has multiple incredible benefits for our health in addition to initiating the synthesis of this vitamin. It is critically important to expose yourself to sunlight everyday! If it’s cloudy you can still get UVA, UVB and infrared light- which allow this process to occur (I’m talking go outside… not just standing in the window.)
My favorite sources of dietary vitamin D are: fish oil, I recommend Rosita’s Cod Liver Oil, sardines, salmon (see a trend here… sea foods), egg yolks, and cheese. Many foods are fortified with it which are less optimal options as this vitamin D is generally synthetic. Remember that vitamin D should be consumed with fat! No wonder all those fatty foods are great sources of vitamin D.