Vitamin D is a well known nutrient, however, I think few
people really understand the significance of this important vitamin. To begin with, vitamin D should hardly be classified as a
vitamin at all, since it is really hormone that helps to signal our bodies
calcium status (1). However vitamin D (VD) has been
implicated in a range of processes including obesity, renal disease,
cardiovascular disease, male fertility and even sex hormone production (2,3). With all these different actions of VD
it is tough to know where to start, as there is so much research on how VD
affects so much of our lives. I do
think these many actions are very interesting, and well deserving of a post in
their own right, but I would like to focus this post on VD’s interactions with
the immune system, as that is a topic consistently on my mind these days. To do that we will first go over a
quick look at VD metabolism, and then get into its effects on immunity, and
finish up with some thoughts about our own VD status.
Vitamin
D Metabolism
As humans there are two main ways we can get VD: through sun
exposure and supplementation. We
will go over the optimal VD levels at the end of the post, but first lets see
how sunlight affects our VD status.
