In the first large-scale, prospective study to investigate the relationship between vitamin D levels and MS, researchers at the Harvard School of Public Health (HSPH) have found an association between higher levels of vitamin D in the body and a lower risk of MS. The study appears in the December 20, 2006, issue of the Journal of the American Medical Association.
"If confirmed, this finding suggests that many cases of MS could be prevented by increasing vitamin D levels. Although these levels could be increased by taking supplements, before any recommendation is made it is important to establish whether we are seeing a true causal association or whether vitamin D levels are only a marker of MS risk," said Alberto Ascherio, senior author of the study and associate professor of nutrition and epidemiology at HSPH.
MS is a chronic degenerative disease of the central nervous system. It affects some 350,000 people in the U.S. and 2 million worldwide, and occurs most commonly in young adults. Women, who are affected more than men, have a lifetime risk of about 1 in 200 in the U.S. Vitamin D is a hormone manufactured naturally in the body, and its levels can be increased with exposure to sunlight, consumption of foods rich in vitamin D, such as fatty fish, and by taking supplements.
The researchers, led by Ascherio, worked in collaboration with colleagues in the U.S. Army and Navy to determine whether vitamin D levels measured in healthy young adults predict their future risk of developing MS. The investigation relied on a study population of more than 7 million individuals, whose serum samples are stored in the Department of Defense Serum Repository. Between 1992 and 2004, 257 U.S. Army and Navy personnel with at least two serum samples stored in the repository were diagnosed with MS. A control group, consisting of participants who did not develop MS, was randomly selected from the study population. Serum samples were analyzed for levels of 25-hydroxyvitamin D, a good indicator of vitamin D availability to tissues, and individuals were divided into five groups of equal size according to their average levels. Because vitamin D levels are strongly influenced by skin color, separate analyses were conducted among whites, blacks, and Hispanics.
The results showed that, among whites, MS risk declined with increasing vitamin D levels--the risk was 62% lower among individuals in the top fifth of vitamin D concentration (corresponding approximately to levels above 100 nmol/L or 40 ng/mL) than among those in the bottom fifth (approximately below 63 nmol/L or 25 ng/mL). The association was strongest among individuals who were younger than 20 when they first entered the study. No significant association was found among blacks and Hispanics, possibly because of a smaller sample size and the lower levels of vitamin D found in those groups. The average age of onset of MS cases was 28.5 years old; there was no significant difference in the results between men and women.
"The results of this study converge with a growing body of experimental evidence supporting the importance of vitamin D in regulating the immune system and suppressing autoimmune reactions, which are thought by most experts to play a key role in the development of MS," said Ascherio. Kassandra Munger, first author and a doctoral candidate in nutrition at HSPH, added, "The amount of vitamin D that is needed to reach levels associated with MS protection is largely considered safe, and in fact higher vitamin D levels could be beneficial to prevent osteoporosis and other chronic diseases."
The researchers note that there could be other possible explanations for the protective role of vitamin D. For example, it’s possible that exposure to UV light from the sun--the major determinant of serum levels of 25-hydroxyvitamin D--could protect people in other ways than increased vitamin D production.
The authors suggest further studies exploring how vitamin D may protect individuals from developing MS. "Although the results of this study are quite encouraging, reasonable certainty of a protective effect of vitamin D supplements requires direct experimental evidence in a large trial. Meanwhile, we are planning to expand our study to obtain more accurate data on the importance of age and of the vitamin D levels that need to be achieved for optimal protection," said Ascherio.
Todd Datz | EurekAlert!
How cancer metastasis happens: Researchers reveal a key mechanism
19.01.2018 | Weill Cornell Medicine
Researchers identify new way to unmask melanoma cells to the immune system
17.01.2018 | Duke University Medical Center
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
22.01.2018 | Materials Sciences
22.01.2018 | Earth Sciences
22.01.2018 | Life Sciences