Researchers have known for years that there is some connection between multiple sclerosis (MS) and vitamin D. Patients newly diagnosed with MS, for example, almost always show below-normal levels of vitamin D, and many studies have indicated that people who get plenty of vitamin D, either through their diet or via sun exposure, are at a lower risk of developing the disease.

Another intriguing connection lies in the fact that the disease is less common in populations that live closer to the Equator. Given that proximity to the Equator generally means more exposure to sunlight, and that the body naturally produces vitamin D when exposed to the sun, the correlation seems to be yet another important link between vitamin D and MS.

Still, many questions remain:

  • Is adequate access to vitamin D itself a preventer of MS, or is a normal vitamin D level simply a sign of another condition that limits the disease?
  • Do vitamin D supplements merely prevent the development of MS, or can supplements help lessen symptoms in those who already have the disease?
  • If vitamin D supplements are helpful, what is the optimal dose?

In the video below, these questions are addressed by Dr. Ellen Mowry, Associate Professor of Neurology at Johns Hopkins University:

Vitamin D and MS: The Current Research

To help answer these questions, researchers are focusing their efforts on understanding the links between vitamin D and the development of MS, the role of both genetics and environmental factors connecting vitamin D levels and MS, the effectiveness of supplements for MS patients, and the ideal dosage of supplements.

Current research projects include:

  • Ohio State University researchers are looking for connections between infants with low levels of vitamin D and the development of MS later in life. This research is attempting to determine if vitamin D may protect the central nervous system as it develops early in life.
  • Researchers at Johns Hopkins are looking for links between genetic predictors, vitamin D, and the development of MS. This team is also studying the effects of different supplement dosages on patients in the relapsing-remitting phase of MS.
  • Researchers at the University of Vermont are studying mice to better understand the connection between exposure to ultraviolet light and the development of MS.

Vitamin D Supplements for MS Patients

Although the research isn’t yet complete or conclusive, some studies have shown promising results in using vitamin D supplements to help patients who already have MS. These studies have suggested several possible benefits, including:

  • Reduction in the severity and frequency of MS symptoms.
  • Improved quality of life during the progression of the disease.
  • Extension of the time period between the onset of the relapsing-remitting phase of the disease and the later progressive phase.

Is Vitamin D the Answer?

A crucial question that remains unanswered is whether or not vitamin D itself is the key factor in protection from the disease, or whether its presence or absence is merely a sign that something else is going on in the bodies of patients.

  • Vitamin D levels seem to be associated with the protection of the nervous system, but that may be because vitamin D helps to boost the body’s immune system. The bolstered immune system, not vitamin D itself, may be the key to defending against MS, and there may be other (and potentially more effective) routes to a more robust immune system.
  • The correlation between sunlight and MS is also mysterious. Although vitamin D is a byproduct of exposure to the sun, there may be some other component of exposure to ultraviolet light that protects the body from MS.

Dangers of Too Much Vitamin D

Doctors will typically recommend vitamin D supplements for MS patients, but there’s no clear consensus yet on the dose that has the optimal effect on the disease. While there may be a temptation to administer high doses, an excess of vitamin D can lead to detrimental side effects that hit MS patients particularly hard.

The Institute of Medicine recommends a daily dosage of 600 international units (IUs) for adults 70 years old or younger and 800 IUs for patients older than 70. The Institute recommends, however, that no one take more than 4,000 IUs per day.

When an MS patient is diagnosed with a vitamin D deficiency, doctors will usually prescribe a high dosage of supplements–as much as 50,000 IUs per week–for 90 days because it will take some time for vitamin D in the body to reach normal levels, especially in patients with severe MS. After a 90-day check determines that vitamin D levels are normal, doctors will generally switch to a maintenance dosage of 2,000-5,000 IUs per day.

Overconsumption of vitamin D supplements can lead to elevated calcium levels in the blood and urine and can have toxic side effects, including:

  • Nausea and vomiting
  • Constipation
  • Weight loss
  • Weakness
  • Kidney stones

There is no doubt that there is a connection between vitamin D and MS, and as researchers look for answers to the questions surrounding the connection, they just may uncover the secrets to effectively fighting the disease.

*Content published by the United Brain Association (UBA), such as text, graphics, reports, images, and other materials created by UBA and other materials contained on are for informational purposes only. The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health providers with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on the

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