Multiple sclerosis (MS) is a chronic, progressive disorder that affects the nervous system. It results in loss of both sensory and motor function due to demylination of nerve fibers. The cause of MS is not fully understood, some believe it is due to an autoimmune reaction in the body following a viral infection.
Research has focused on building a better understanding about the cause of MS as well as which lifestyle factors increase the risk for developing the condition. Currently there are about 500,000 people in the US with MS and more than 2 million worldwide. It is more common in people living in higher altitudes.
A recent study found that levels of Vitamin D in the blood may have some effect on the incidence of MS. Researchers at the Harvard School of Public Health analyzed data from military personnel. In particular they were looking for serum levels of Vitamin D, race, and occurance of MS.
Out of more than 7 million participants, only 257 developed multiple sclerosis (<0.004%). The samples of those persons with MS were compared to equal numbers of military personnel without the condition.
The results were published in the Journal of the American Medical Assocation this December.
Vitamin D levels were significantly associated with a decreased risk of multiple sclerosis in caucasians only. Risk was decreased by 62 percent when comparing those with the highest levels of Vitamin D to those with the lowest level of Vitamin D.
There was no association between Vitamin D status and MS risk in African Americans or Hispanics. This may be due to the small number in the study, or their levels may be too low to provide a comparison.
Vitamin D is present in some foods, especially dairy, eggs, and meat. Most of our Vitamin D is obtained from exposure to sunlight. Other studies have shown that individuals living in higher altitudes have lower levels of Vitamin D (due to less sun exposure). Persons of color also have lower levels of Vitamin D.
Vitamin D is invovled in several processes in the body, most importantly calcium and bone metabolism and the immune system.
Look for more research in this area. A clinical trial studying the effects of Vitamin D on MS symptoms may provide more information about this possible relationship. At this time the authors do not recommend taking a Vitamin D supplement to protect against multiple sclerosis, but a little sun never hurt anyone.
Posted by Dr. Christina Gutierrez on December 27, 2006 03:57 PM
