Dr. Margherita Cantorna, assistant professor of nutrition, says the study has not been in progress long enough to observe changes in the clinical symptoms of the disease in the patients who participated.

However, blood samples drawn after just 6 months of Vitamin D supplementation show an increase in transforming growth factor beta-1 (TGF-Beta), which is associated with the remission and suppression of the immune response that produces symptoms in MS patients. In addition, the researchers found a decrease in interleuken-2, which is associated with the cells that induce MS.

Cantorna's student, Brett Mahon, a doctoral candidate in nutrition, detailed the study results last week at the Experimental Biology 2001 conference in Orlando, Fla. The paper, "Altered Cytokine Profile in Patients with Multiple Sclerosis Following Vitamin D Supplementation," is co-authored by Dr. Felicia Cosman, medical director, Clinical Research Center, S. A. Gordon and J. Cruz, all of Helen Hayes Hospital, and Cantorna. Mahon is first author.

As a postdoctoral fellow at the University of Wisconsin, Madison, Cantorna and others had shown, in experiments with mice, that vitamin D supplementation could completely prevent the development of MS in susceptible animals. After Cantorna joined the faculty at Penn State, she learned of Dr. Cosman's research program which centers on investigating whether a low level vitamin D deficiency in MS patients might account for the incidence of brittle bones.

Cantorna asked Cosman for blood samples from the participating patients to see if the same changes she had observed in mice also occur in humans who receive vitamin D supplementation. She found that the results were, in fact, similar at the blood chemistry level.

Multiple sclerosis is an autoimmune disease in which the victim's own immune system attacks the spinal cord and brain. The disease afflicts about 350,000 people in the United States alone. Its cause is thought to be a complex interaction of genetics and environmental forces that are not completely understood.

Cantorna and others hypothesize that one crucial environmental factor involved in the development of the disease is the amount of sunlight a person receives. Exposure to sunlight catalyzes the production of vitamin D in the skin. In low sunlight, the skin produces significantly less vitamin D.

In support of a connection among sunlight, vitamin D and multiple sclerosis, Cantorna points out that the incidence of the disease is nearly zero near the equator and increases with latitude in both hemispheres. In addition, Switzerland has high MS rates at low altitudes and low MS rates at high altitudes. Ultraviolet light is more intense at higher altitudes, resulting in the skin manufacturing more vitamin D.

Other evidence of an MS/vitamin D link comes from Norway, where MS rates are higher inland than on the coast where larger quantities of fish are consumed -- which are rich in vitamin D.

While Cantorna's research and MS's geographical distribution suggest a connection between vitamin D and MS, she cautions that the vitamin's exact role is still unclear.

The College of Health and Human Development faculty member recommends MS patients to continue to follow their personal physician's advice. Since vitamin D can be toxic in high doses, it would not be a good idea to begin taking vitamin D pills available over-the-counter in large amounts.

On the other hand, since adequate amounts of vitamin D are difficult to get from diet and because MS patients often have to stay out of the sun, a vitamin D supplement at the current recommended daily requirement level ought to be considered. There are potential benefits for bone health and for the immune system as well.

The project was supported by two grants from the National Multiple Sclerosis Foundation -- one to Cantorna and the other to Cosman.