Vitamin D.  Specifically in its protective role against autoimmune diseases, relapsing attacks (see “adaptive immunity” on the left), and innate immunity (diagram on the right – think colds and flus).  Last summer, I spent a lot of time looking at the relationship between Vitamin D and MS (Multiple Sclerosis) as well as other Th1 mediated autoimmune diseases (type 1 diabetes, Rheumatoid Arthritis).  If the above diagram isn’t enough for you (specifically Th1 and Th17 in relation to MS), then check this out.

Next time you are out in the sun or on vacation, don’t forget to protect yourself against UV radiation with some non-toxic sunscreen.  But not before getting 10-20 minutes of sun exposure on bare skin, so that this reaction may move forward in your body:

(Click here for a PubMed link to the paper.)  This amount of time is not true for everyone and varies with latitude.  I have dark skin, so tend more towards the high end of time, however fair skinned individuals must be careful.  And be sure to do skin checks weekly.

What do you think about Vitamin D? Do you take it regularly?