Vitamin D & Multiple Sclerosis Risk
Vitamin D may play a key role in the development of Multiple Sclerosis (MS). Our visual explainer shows all the key data behind this link.
Professionally Reviewed by Charles Li, MD

Vitamin D

Key Facts
what is it?
where to get it
Vitamin D
what is it?
Key Facts
  • type
    fat soluble
  • source
    diet, skin
  • other names
    calciferol, cholecalciferol
Use List

bone growth



Vitamin D
where to get it
the sun

your body can create vitamin D with assistance from the sun


some foods such as milk and fish contain vitamin D


Vitamin D can also be obtained from dietary supplements

Key facts: Vitamin D plays a key role in bone growth, calcium absorption, and your immune system. Unlike some vitamins, your body can produce it with the help of the sun. Sunlight helps catalyze a key reaction in the production of Vitamin D.

Why Vitamin D Might Play a Role

Many know that Vitamin D helps grow strong bones. Did you know that it also affects a wide range of functions throughout the body including immunity, muscle function, and possibly even cancer risk? Some studies have shown that Vitamin D may play a key role in the development of Multiple Sclerosis.

Multiple Sclerosis

Key Facts
what is it
Multiple Sclerosis
what is it
disease type
Body System affected
brain & Spinal cord
key symptoms


Vision problems


Multiple Sclerosis
age at diagnosis


MS is typically diagnosed in early adulthood

global cases

2.2 mil.

about 2.2 million people have multiple sclerosis worldwide

gender distribution
26% Male
74% Female

Key Facts: Multiple sclerosis is an autoimmune disease that affects the central nervous system. In Multiple Sclerosis, your immune cells attack the insulation around your nerve cells. This can lead to a wide range of symptoms including numbness, vision problems, and dizziness.

Multiple Sclerosis & Sunlight

Geography & Multiple Sclerosis

Multiple Sclerosis tends to be more common in regions that receive less sunlight. Scientists theorized that vitamin D may play a role in Multiple Sclerosis risk.

Map of global Multiple Sclerosis Cases. Red: High death rate from Multiple Sclerosis. Yellow: Low death rate from Multiple Sclerosis. Source: Chris55 / CC BY-SA

Vitamin D Levels & Multiple Sclerosis Risk

Why this matters

This study shows that the amount of Vitamin D in your blood correlates with your Vitamin D risk if you are White. Interestingly, this same effect was not found in African Americans.

Data Source Quote:

"Our results converge with a growing body of evidence supporting a protective role for vitamin D in MS development. Vitamin D is a potent immunomodulator, and several studies have shown that administration of the biologically active hormone 1,25-dihydroxyvitamin D prevents EAE onset and progression in mice."

Source: Serum 25-Hydroxyvitamin D Levels and Risk of Multiple Sclerosis

Vitamin D Supplements & Multiple Sclerosis Risk

A prospective study found that nurses who took the most Vitamin D supplements had the a significantly lower risk (p=0.006) of developing Multiple Sclerosis compared to those who took the lowest amount of Vitamin D.

Why this matters

This study suggests that taking vitamin D supplements may correlate with a lower risk of developing multiple sclerosis. This is just a correlation, but it suggests that supplementation may be worthwhile if you don't get enough sunlight.

Data Source:

"Intake of vitamin D from supplements was also inversely associated with risk of MS; the RR comparing women with intake of ≥400 IU/day with women with no supplemental vitamin D intake was 0.59 (95% CI = 0.38 to 0.91; p for trend = 0.006). ... These results support a protective effect of vitamin D intake on risk of developing MS."

Source: Vitamin D intake and incidence of multiple sclerosis

Key Takeaways

There is evidence supporting that Vitamin D levels and Vitamin D supplement intake may correlate with Multiple Sclerosis risk. As with all observational studies, we can't yet determine whether Vitamin D causes a reduction in risk.


How Vitamin D is Made
Chart of how vitamin D is made

How Vitamin D is Made: Skin cells are believed to create 7-Dehydrocholesterol. UVB Rays from the sun convert this to Vitamin D3. Your liver and kidneys convert this to active Vitamin D. Vitamin D is then distributed throughout the body.

More Information on Vitamin D

Vitamin D Rich Foods:

"Oily fish such as salmon, sardines, pilchards, trout, herring, kippers and eel contain reasonable amounts of vitamin D. Cod liver oil contains a lot of vitamin D, but don’t take this if you are pregnant "

Vitamin D & Sunlight

"Our body creates vitamin D from direct sunlight on our skin when we're outdoors. From about late March/early April to the end of September, most people should be able to get all the vitamin D we need from sunlight. "

More Information on Multiple Sclerosis

Multiple Sclerosis Prognosis

"We found a 7-year shorter life expectancy and almost threefold higher mortality in MS compared with the general population. A rise in survival in MS was observed during the entire observation period."