Sunlight Vitamin Holds The Key To Autoimmune Disease
Vitamin D, commonly known as the ‘Sunlight Vitamin’ is once again showing itself to be a nutritional superstar.
Commonly prescribed to help maintain calcium regulation and bone health, Vitamin D is now also implicated in a range of biological functions including metabolic health, mood regulation and immune function.
Vitamin D is not a vitamin in the traditional sense of the word, it acts more as a steroid hormone in the body, interacting with cell receptors and endocrine organs and glands.
Incredibly, research now shows that Vitamin D directly and indirectly regulates over 2000 genes in the body. Many of these genes are involved in the development of autoimmune disease via immune cell regulation processes.
Autoimmune diseases are the third leading cause of morbidity and mortality in the industrialised world, surpassed only by cancer and heart disease. (Arnson et al. 2007)
Research shows that Vitamin D supplementation may be effective in autoimmune conditions such as type 1 diabetes, systemic lupus erythematosus, inflammatory bowel disease and multiple sclerosis.
How Do Autoimmune Diseases Develop?
Autoimmune diseases occur when the immune system loses the ability to distinguish between foreign antigens (bacteria and viruses), and self-body tissues, and as a result, inappropriately attacks self-tissues.
The cellular changes involved in autoimmune disease are related to our T-helper immune cells. There are two types of T-helper cells:
- T-helper 1 (TH1) cells which drive cellular immunity and provide defence against intracellular infections such as viruses, fungi, bacteria and cancerous growths.
- T-helper 2 (TH2) cells which drive humoral immunity and provide defence against extracellular or foreign antigens and parasites.
When the body is healthy and functioning normally, the immune system is able to regulate T-helper cell activity.
However when the balance between TH1 and TH2 cell activity is lost, and one type becomes dominant, health problems such as allergies (usually associated with TH2 dominance) or autoimmune diseases (usually associated with TH1 dominance) develop.
The causes of autoimmune diseases are still not fully understood, however risk factors for autoimmune disease development are currently shown to include: genetic predisposition to autoimmunity, environmental toxin exposure including heavy metals, prior infections, gastrointestinal damage such as leaky gut or dysbiosis, chronic stress and inflammation, and nutritional deficiencies- in particular Vitamin D.
The Role of Vitamin D in Regulating Immune Function
It seems that the mothers and grandmothers of our generation were onto something when they force fed their children cod liver oil, which is rich in vitamin D, to prevent and treat infections.
As far back as 1849, practitioners were successfully treating tuberculosis patients with vitamin D.
Nowadays, the importance of vitamin D on the regulation of immune cells has become increasingly recognized with the discovery of the vitamin D receptor (VDR).
VDRs are present in most cells of the body, but have been found to be concentrated near a number of genes known to be associated with susceptibility to autoimmune disease, and in a number of cells of the immune system including circulating monocytes, dendritic cells and activated T-helper cells.
Vitamin D alone has been shown to produce powerful antimicrobial peptides such as cathelicidin and β defensin 2 to improve immune defense to infections. (Youssef et al. 2011)
The role of Vitamin D in autoimmune disease involves its binding with various VDRs to cause gene transcription that inhibits immune cells from expressing a T-helper 1 dominant profile and promotes a T-helper 2 cellular profile.
Active Vitamin D also helps promote the growth and differentiation of immature T-helper cells to regulatory T- cells associated with anti-inflammatory cytokines (immune cells) such as Interleukin-10 and transforming growth factor-beta.
A recent study by Oxford University actually showed that Vitamin D had a significant effect on the activity certain genes, including IRF8, that has been previously associated with autoimmune diseases such as Multiple Sclerosis, and PTPN2, which has been associated with Crohn’s Disease and type 1 Diabetes.
Genetic Influences on Vitamin D Metabolism
Just as Vitamin D can influence the function of your genes, your genes can also influence how your body metabolises vitamin D from any source (eg. sunshine or supplementation).
Current research suggests that there are at least three genes involved in vitamin D metabolism- GC, DHCR7 and CYP2R1.
If you have a variation in any of these genes it may affect the way your body metabolises vitamin D and may result in vitamin D insufficiency, and consequently greater risk of disease.
How To Tackle D-ficiency and Autoimmune Disease
There is no doubt that Vitamin D deficiency is already a global epidemic. Even in Australia, Vitamin D deficiency is all too prevalent, and deficiency is commonly found in individuals with autoimmune diseases such as Chron’s disease and Type 1 diabetes.
There are a number of reasons for deficiency, including sedentary indoor lifestyles, advancing age, darker skin pigmentation, low dietary Vitamin D intake and even obesity.
To read more about the causes of Vitamin D deficiency and how to safely restore your levels, click here
The health of your digestive system, liver and kidneys is also paramount to maintaining healthy vitamin D levels and immune function.
Current research shows that conditions like leaky gut disease and bacterial dysbiosis are major causes of immune dysfunction and may contribute to autoimmune disease development.
It is important to limit or avoid foods in your diet that can cause abnormal immune responses and may lead to more serious immune dysfunction. Gluten, a protein found in wheat, and casein, a protein found in dairy, are common food allergens that can do more than just damage your gut!
If you suspect you have a food intolerance, are suffering from poor digestive health, allergies or have an autoimmune disease, it is important to remove these foods from your diet completely.
You can also get tested for a range of food allergies through Emed to end the guessing game- and uncomfortable symptoms- for good!
Finally, the liver and kidneys play an important role in converting Vitamin D to it’s biologically active form and also help to process and eliminate toxins from the body that can interfere with immune function.
*Ergocalciferol (Vitamin D2) & Cholecalciferol (Vitamin D3)= Supplemental/dietary forms of Vitamin D, 1,25(OH02VitD3 = Metabolically active form of Vitamin D
So, if like most of us your detoxification organs are under stress, it is likely that you are not efficiently metabolising Vitamin D and would benefit from some professional assistance to naturally improve your liver and kidney function.
Further Reading:
- Probiotics for Immune Balance
- Australians Still Low in Vitamin D
- Research Insight- Vitamin D Needed For Gene Health
References
Arnson, Y. et al. 2007, Vitamin D and autoimmuntiy: new aetiological and therapeutic considerations, Annals of the Rheumatic Diseases, Vol. 66(9)
Margherita, T.C. et al. 2004, Mounting Evidence for Vitamin D as an Environmental Factor Affecting Autoimmune Disease Prevalence, Experimental Biology and Medicine, Vol 299(11), pgs 1136-1142
Youssef, A.A. et al. 2011, Antimicrobial implications of vitamin D, Dematoendocrinology, Vol 3(4), pg 220-229