Can vitamin D be used to prevent or treat MS?

In recent years, a lot of attention has been put on the health benefits of vitamin D. It's not surprising, then, that vitamin D's usage by MS patients has also been widely discussed and studied.

What Are the Health Benefits of Vitamin D?

It's been known for years that vitamin D is essential for preventing many diseases—vitamin D deficiency can lead to rickets, osteomalacia, osteoporosis, and other conditions. Conditions from tuberculosis to the common cold have been linked to deficiencies in vitamin D, but these connections are a bit less firm.

What Does Vitamin D Have to Do with MS?

As one study noted, "Vitamin D is hot in MS research." Investigators have confirmed that the farther away from the equator people live, the more likely they are to develop MS. This revelation led many experts to believe that vitamin D deficiencies might be linked to the development of the disease.

Several studies, in fact, have found that people with higher levels of vitamin D have a lower risk of being diagnosed with MS. But does this prove that having high levels of vitamin D actually prevents MS?

The answer, at least for now, is no. There may be other factors at work. For example, a 2010 study found that genetic factors and environmental risks also play a role in the prevalence of MS, and the issue is still a matter of considerable debate.

Can Vitamin D Supplements Affect the Course of MS?

Maybe, more research is needed. A few small studies have found that vitamin D levels are lower during MS relapses, and relapses are more common during the months when levels of the vitamin are lowest. So, it's possible that the nutrient might have some effect on the frequency and severity of MS symptoms. Other studies, however, have found little or no evidence that vitamin D supplementation affects MS symptoms. Therefore, most experts agree that it’s too soon to recommend vitamin D supplements for the management of MS.

However, all people—MS diagnosis or not—should make sure that they are getting enough vitamin D. It plays a critical role in bone growth and skeletal strength, proper absorption of calcium, modulating cell growth, immune function and reducing inflammation, among other things.

What Are the Best Sources of Vitamin D?

Only a few foods, like oily fish (salmon, mackerel, tuna, sardines), liver and vitamin D-fortified foods contain vitamin D. People can also synthesize the vitamin by exposing their skin to UV light, and some experts recommend people get at least 15 minutes of direct exposure to sunlight three times a week. But that recommendation might be inadequate for older people or those with darker skin, since they synthesize vitamin D less efficiently.

This is not to say that sunbathing to ensure proper vitamin D levels is recommended. UV rays remain a major concern, because of their role in the development of skin cancer. And most people with MS need to avoid overheating.

How Much Vitamin D Should I Get?

That, too, is a matter of some debate. The current recommended daily intake of vitamin D is 800 IU for adults over 70 and 600 IU for children and adults up to age 70.

Some experts have called even these recommendations inadequate, noting that vitamin D is safe except at very high levels, and vitamin D supplementation could be a very inexpensive way to prevent many diseases. For them, daily intake from 1,000 to 3,000 IU is adequate.

Your best source of information is your doctor, who may advise getting more vitamin D if you have osteoporosis or another condition that would benefit from vitamin D supplementation.


Ascherio, A et al. Vitamin D and multiple sclerosis. Lancet Neurology 2010; 9: 599–612.

Handel, AE et al. The Epidemiology of Multiple Sclerosis in Scotland: Inferences from Hospital Admissions. PLoS One. 2011; 6(1): e14606. Published online 2011 January 27.

Handel, AE et al. Genetic and environmental factors and the distribution of multiple sclerosis in Europe. European Journal of Neurology, Volume 17, Issue 9, pages 1210–1214, September 2010.

Institute of Medicine Report: "Dietary Reference Intakes for Calcium and Vitamin D," Nov 2010

Lucas, RM et al. "Sun exposure and vitamin D are independent risk factors for CNS demyelination." Neurology 76. Feb. 8, 2011.

National Multiple Sclerosis Society

NIH: Office of Dietary Supplements: Dietary Supplement Fact Sheet: Vitamin D.

Publication Review By: the Editorial Staff at

Published: 20 Mar 2011

Last Modified: 25 Sep 2015