There is much debate regarding the ideal way to categorize vitamin D. It does not fit the classic definition of a vitamin. Some call it a pre-hormone, while others argue it’s a prohormone. Regardless of how the parent compound, cholecalciferol (or vitamin D3), is categorized, one thing is clear. Once vitamin D is activated in the body, it acts as a steroid hormone. This means vitamin D has the power to turn genes on and off, affecting cells in the body throughout their life cycle.
But what happens when vitamin D levels become too low? Although in most cases, individuals don’t develop symptoms of deficiency, this can lead to chemical processes becoming altered in the body, most commonly leading to increased inflammation and altered immune function. Now, what happens when an individual is immunocompromised to begin with? Research suggests that in many cases, this may lead to increased disease activity and symptom severity.
Let’s take systemic lupus erythematosus (SLE) as a example. SLE is an autoimmune disease that occurs when the body’s immune system mistakes its own healthy tissue for foreign invaders and begins to attack itself. This results in inflammation of the affected tissues or organs. Although lupus can act on every system in the body, the skin, joints and kidneys are most commonly affected by this disease.
The two main components of lupus also happen to be two important systems regulated by vitamin D: the immune system and inflammatory response. Therefore, it comes as no surprise that an abundance of research has produced positive findings regarding the relationship between vitamin D and lupus. In fact, research has found that vitamin D deficiency is associated with increased disease activity among both children and adults with lupus. In addition, vitamin D supplementation has been proven to help decrease disease activity, thus improving symptom severity.
Researchers theorize that the mechanism behind vitamin D’s role in immunity among lupus patients is due to its ability to regulate self-reactive T-cells and B-cells. However, according to a new study, an additional vitamin D mechanism may account for this relationship.
Sturges, M. & Cannell, JJ. Study offers mechanism by which vitamin D may improve lupus symptoms. The Vitamin D Council Blog & Newsletter, 1/2018.
Yazdanpanah, E. et al. Vitamin D3 alters the expression of Toll-like receptors in peripheral blood mononuclear cells of patients with systemic lupus erythematosus. Journal of Cellular Biochemistry, 2017.