Vitamin D is often recommended by doctors to help maintain the health of bones and teeth, regulate mood, and aid in weight loss. But did you know that it may also help lessen the symptoms of multiple sclerosis (MS) or possibly even decrease your chances of getting MS?

We’ve known for years that the incidence of MS, and the age of onset, is lower the closer you are to the equator.

That’s great news if you live in Southeast Asia and the tropics. But if you call the United States home, you know all too well that vitamin D deficiencies are common.

Researchers are looking at whether or not these low levels of vitamin D have anything to do with the 200 new cases of MS that are diagnosed each week in the United States.

They’re also focusing on promising data and anecdotes from the medical and MS communities about the connection between vitamin D supplements and the decrease of symptoms related to MS.

Why are vitamin D supplements important for people with MS?

It’s no secret that vitamin D is an essential vitamin for everyone. But if you have MS, it may be even more important to pay attention to your vitamin D blood levels and supplement with extra sources of vitamin D if you’re deficient.

Dr. Brian Steingo, a neurologist with Sunrise Medical Group, says vitamin D deficiency is associated with increased risk of developing MS (demonstrated even in the risk for infants of pregnant women deficient in D) and an increased risk of worsening in those with MS.

According to the National Multiple Sclerosis Society, several studies have shown that there’s an association between low vitamin D levels and an increased risk of having attacks (relapses, also called exacerbations) and developing new brain or spinal cord lesions.

Plus, researchers and doctors have found that low levels of vitamin D are also associated with increased levels of disability.

“Several studies have shown that MS patients had lower vitamin D levels in the winter, and that the lower vitamin D levels correlated with increased risk of relapse and worse disease progression,” explains Dr. Michael Sy, neurologist at UC Irvine Health.

MS has also been linked to a higher incidence of developing osteoporosis, so supplementing with vitamin D can help increase bone health and decrease the risk factors associated with developing this condition.

Low levels of vitamin D may lead to increased risk of:

  • developing MS
  • worsening symptoms, flare-ups, and faster disease progression
  • developing new brain or spinal lesions
  • osteoporosis

What are the optimal vitamin D levels for someone with MS?

Since the studies on vitamin D and MS are relatively new, there’s not a definitive answer about optimal levels. That said, many experts agree that people with MS need higher levels of vitamin D than those without MS.

These levels are not easy to obtain through sunshine and diet alone. You will almost always need to supplement appropriately to achieve these. Getting your baseline levels tested is very important as well.

Experts agree that people with MS need higher levels of vitamin D than those without MS.

Steingo says the normal range for vitamin D levels in most labs is 30 to 100 nanograms per milliliter (ng/mL). But for people with MS, he says the goal is to aim for a level of 70 to 80 ng/mL.

Dr. Rob Raponi says that, in his clinical experience, a good majority of people have a very hard time maintaining vitamin D adequacy year-round if they’re not taking supplements.

“Personally, I don’t like to deal with ‘adequate.’ I always strive for ‘optimal,’ and optimal levels of vitamin D for someone with MS should be no lower than 90 ng/mL and as high as 125 ng/mL,” Raponi says.

What vitamin D blood level is optimal for someone with MS?

  • There’s currently not enough research to be definitive.
  • But experts agree that levels should be higher than for people without MS.
  • Dr. Steingo advises to aim for 70 to 80 ng/mL.
  • Dr. Raponi recommends between 90 and 125 ng/mL.
  • Talk to your doctor to determine the optimal level for you.

The importance of baseline blood tests

Before you head to your local health food store, make an appointment with your doctor for a baseline blood test to determine your vitamin D levels. You should also talk with them about the appropriate dose of vitamin D.

Dr. David Mattson, a neurologist at Indiana University Health, says that if someone has a low vitamin D level at the time of an MS diagnosis, they may be predisposed to increased MS disease activity. “While this is not a hard conclusion, rather, a suggestion, we tend to check levels at diagnosis and supplement if levels are low, as a protective factor,” he shares.

The amount of vitamin D you add as a supplement depends on many factors, such as your diet, your current blood levels, and other supplements you may be taking that contain vitamin D.

Since Vitamin D is fat soluble, taking high doses for extended periods of time can cause toxic accumulation, Raponi points out. He recommends having your vitamin D levels checked before beginning to supplement and again within three months of starting to see what level they’ve risen to.

When levels rise to optimal ranges, dosing needs to be reduced in order to maintain that level and not to increase further.

Vitamin D sources and supplements

The adult daily requirement of vitamin D is 600 units (IU) per day. But Mattson tends to recommend 1,000 to 2,000 IU per day to people with MS, even if levels are normal, to boost the protective factor against MS activity.

“If vitamin D levels are low, I tend to recommend 2,000 units per day. Some [doctors] would have patients take 50,000 units per week until levels have normalized and then switch to a more typical daily dose as maintenance,” Mattson explains.

Raponi says good food sources of vitamin D include fish (the smaller, the better), liver, mushrooms, and eggs. Since supplementing is very important for people with MS, he recommends looking for a good vitamin D supplement.

“I always recommend a drop form, suspended in a healthy fat (MCT oil is a good choice) and always ensuring you are supplementing with the active form, vitamin D3,” explains Raponi. “Any supplement you find in the D2 form, or as a tablet or capsule that is not suspended in a fat, is less effective and a waste of your money,” he adds.

How to choose a vitamin D supplement
  • Shop for vitamin D drops.
  • Look for vitamin D3 drops — not D2.
  • Suspend dose in MCT oil or another healthy fat.
  • Talk to your doctor about what dose is right for you.

While the studies show a promising trend, many experts say more research is needed on the optimal dose of vitamin D for reducing the risk of MS.

However, despite the lack of definitive evidence, experts say vitamin D is viewed as safe, inexpensive, and likely to provide a benefit to people with MS, especially if they’re considered vitamin D deficient.


Sara Lindberg, BS, M.Ed, is a freelance health and fitness writer. She holds a bachelor’s in exercise science and a master’s degree in counseling. She’s spent her life educating people on the importance of health, wellness, mindset, and mental health. She specializes in the mind-body connection, with a focus on how our mental and emotional well-being impacts our physical fitness and health.

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