Multiple sclerosis, or MS, is a progressive inflammatory disorder of your central nervous system. MS is believed to arise from an abnormally robust immune response that causes destruction of the protective insulation surrounding your nerve fibers. This damage disrupts the conduction of electrical impulses through your nervous system. Vitamin D may help to modulate the immune response in patients with MS, but you should ask your doctor if you need extra vitamin D.
Activation
Vitamin D is a generic term for a number of compounds, some of which exert important biological effects in your tissues. Vitamin D2, or ergocalciferol, is a form of vitamin D produced by plants. Vitamin D3, or cholecalciferol, is manufactured in your skin whenever you are exposed to sunlight. Both vitamin D2 and D3 can also be found in supplements. According to Dr. Richard Bowen at Colorado State University, neither vitamin D2 nor D3 are particularly active in your body. Both must be converted to calcitriol -- also known as "activated" vitamin D -- in a two-step process involving enzymes in your liver and kidneys.
Activated Vitamin D Therapy
In the 1980s, intravenous therapy with calcitriol was introduced for treating dialysis patients, whose kidney disease often interferes with the final enzymatic conversion of vitamin D precursors to calcitriol. Such patients frequently develop problems with calcium metabolism, and providing them with activated vitamin D improves their survival, according to a study published in 2011 in the "Journal of the American Society of Nephrology." Currently, there is no evidence that using calcitriol in MS patients with normal kidney function will confer any advantages over taking other forms of vitamin D.
Receptors
Vitamin D's role in calcium regulation and bone health has long been recognized. Scientists now know that nearly every cell in your body possesses vitamin D receptors, or VDRs, which bind to calcitriol, thereby regulating a number of processes in your body. In June 2010, Dr. Martin Hewison at the David Geffen School of Medicine at U.C.L.A. reported that calcitriol, through its effects on VDRs, regulates the entire range of your immune response, and vitamin D insufficiency could play a role in the development and progression of MS, inflammatory bowel diseases and other autoimmune disorders.
Multiple Sclerosis
Vitamin D's link to MS is not fully understood. A study published in the August 2009 issue of "PLoS One," however, demonstrated that higher serum vitamin D levels enhance the function of regulatory immune cells which prevent nerve injury in MS patients. Similarly, the September 2008 "Scandinavian Journal of Immunology" cited a study in which daily supplementation with 1,000 IU of vitamin D and 800 mg of calcium increased blood levels of anti-inflammatory compounds in MS patients. Such findings imply that activated vitamin D plays an integral role in reducing the immune-mediated damage that is characteristic of MS.
Considerations and Precautions
Vitamin D's role in MS or any other immune-related illness has not been completely defined. Furthermore, it is not yet clear what doses of vitamin D are optimal or safe for patients with MS. A 2010 study published in "Neurology" involved 49 MS patients who took doses of 40,000 IU daily for 28 weeks, followed by 10,000 IU daily for another 12 weeks without any adverse effects. The long-term effects of such doses are not known. If you have MS, consult with your physician about the best vitamin D dose for you.
References
- Colorado State University; Vitamins: Introduction and Index; Vitamin D (Calcitriol)
- "Journal of the American Society of Nephrology"; Impact of Activated Vitamin D and Race on Survival Among Hemodialysis Patients; M. Wolf, et al.; July 2008
- "Endocrinology and Metabolism Clinics of North America"; Vitamin D and the Immune System: New Perspectives on an Old Theme; M. Hewison; June 2010
- "PLoS One"; Vitamin D Status Is Positively Correlated with Regulatory T Cell Function in Patients with Multiple Sclerosis; J. Smolders, et al.; August 2009
- "Neurology"; A Phase I/II Dose-Escalation Trial of Vitamin D3 and Calcium in Multiple Sclerosis; J.M. Burton, et al.; June 2010
