Wednesday, March 4, 2015

Just how big of a role does Vitamin D play in your immune system?

Getting your daily dose of sunshine for some good ‘ol vitamin D is common knowledge, but what many people may not know is why getting that daily dose of the sunshine vitamin is so important. In fact, vitamin D has recently been implicated as an important aspect of healthy immune function, for it has been shown to play a role in skeletal health, and more recently, vitamin D has been implicated for its immunosuppressant properties.

A new paper by Skaaby et al. brings to light new research on the relationship between low vitamin D levels as a risk factor for developing an autoimmune disease. Low vitamin D levels occur more frequently in northern latitudes where the sun’s intensity is not sufficient for vitamin D production during winter months. According to recent research, the incidence of autoimmune diseases is also higher in these northern latitudes, suggesting a possible relationship between the two.

Autoimmune diseases are characterized by the body’s inability to recognize “self” and thus the immune system attacks and destroys healthy tissue by mistake. As of now, there are over 80 types of autoimmune diseases that have been accounted for, but the exact cause for many of these remains unknown. Because the study of autoimmune diseases is relatively new in comparison to other fields, this research helps to broaden our understanding of autoimmune diseases and the relationship to potential correlations and/or causalities of risk factors.

You would not believe how useful vitamin D can be to the immune system. According to previous studies, supplementation of vitamin D has therapeutic effects in animals suffering from autoimmune encephalomyelitis, collagen induced arthritis, type 1 diabetes mellitus, inflammatory bowel disease, autoimmune thyroiditis, and systemic lupus erythematosus. Other studies have shown that vitamin D inhibits processes that cause inflammation by suppressing the increased activity of the immune system. Talk about the potential for greatness; vitamin D could potentially be a huge help in humans suffering the same diseases.

Vitamin D has also been shown to have preventative properties in certain diseases such as Diabetes type 1 and multiple sclerosis. In fact, the risk for developing multiple sclerosis was found in a study to be 50% greater when Vitamin D levels were less than 20ng/L in the blood. The low vitamin D levels, especially early in the disease course, predicted a risk factor for long-term multiple sclerosis activity and progression. Similar disease prevention was also seen in children who were supplemented with 2000IU of Vitamin D per day, such that the risk of developing diabetes type 1 was reduced by 30% on average.

Because many studies in the past focused on the association between vitamin d intake and risk for developing autoimmune diseases, a new study decided to direct their time and money to vitamin D status in relation to autoimmune diseases. Because the role of vitamin D in the likelihood of developing autoimmune diseases is not yet concrete, the researchers felt that the status of vitamin D in the blood was a better way to accurately measure the relationship between the two.

This study investigated a total of 12,555 individuals for an association between vitamin D status and the incidence of registry based diagnoses of autoimmune diseases in three Danish populations.The populations were evaluated based on questionnaires, blood tests, and physical examination, and it was found that there were a total of 525 cases of incident autoimmune diseases.

The research found that there was a statistically significant inverse association between vitamin D status and development of an autoimmune disease (ie thyrotoxicosis, type 1 diabetes, multiple sclerosis, iridocyclitis, Chrohn’s disease, ulcerative colitis, psoriasis vulgaris, and polymyalgia rheumatic. In simpler terms, having more Vitamin D in the blood reduced the average participant’s likelihood of developing these diseases!

The findings in Skaaby et al. suggest that a higher vitamin D status is protective to autoimmune diseases, but the study recommends that future studies need to clarify. However, this study presented some pretty interesting and exciting data as evidence of vitamin D’s role in immune function. Indeed, vitamin D’s days in the spotlight are not nearly over, in fact they are just getting started. In the mean time, soak up some sun (with sunscreen of course). This sunshine vitamin is good for you!

Arnson, Y., Amital, H., Shoenfeld, Y. Vitamin D and autoimmunity: new aetiological and therapeutic considerations. Ann. Rheum. Dis. 66, 1137–1142 (2007) .

Duerden, M. (2009). What are Hazard ratios. London: Hayward Medical Communications.

Latina, A., Gullo, D., Trimarchi, F., & Benvenga, S. (2013). Hashimoto's thyroiditis: similar and dissimilar characteristics in neighboring areas. Possible implications for the epidemiology of thyroid cancer. PloS one, 8(3), e55450.

Pludowski, P., Holick, M. F., Pilz, S., Wagner, C. L., Hollis, B. W., Grant, W. B., ... & Soni, M. (2013). Vitamin D effects on musculoskeletal health, immunity, autoimmunity, cardiovascular disease, cancer, fertility, pregnancy, dementia and mortality—a review of recent evidence. Autoimmunity reviews, 12(10), 976-989.

Skaaby, T., Husemoen, L. L. N., Thuesen, B. H., & Linneberg, A. (2015). Prospective population-based study of the association between vitamin D status and incidence of autoimmune disease. Endocrine, 1-8.

Szodoray, P., Nakken, B., Gaal, J., Jonsson, R., Szegedi, A., Zold, E., ... & Bodolay, E. (2008). The complex role of vitamin D in autoimmune diseases. Scandinavian journal of immunology, 68(3), 261-269.

Post Written by Emma Krasovich

1 comment:

  1. The publication by Skaaby et al. can demonstrate a correlation between vitamin D and autoimmune disease. However, correlation does not mean causation, so one cannot say that decreased concentrations of vitamin D in the blood causes autoimmune disorders. Seems as though a lot of ideas are being drawn from preliminary findings, so more research needs to be done. A microbiology study should be conducted to examine the mechanism by which vitamin D interacts with the body's immune system.