People with MS may take vitamin D to help with their overall health, but recent research isn’t clear on whether this vitamin offers noticeable relief with symptoms or MS relapses.

If you live with multiple sclerosis (MS), you may take vitamin D. But this isn’t a guarantee that it will help ease your symptoms or help limit relapses or the severity of MS attacks.

Some research does indicate that people with lower vitamin D levels may be at greater risk for MS relapse, but that doesn’t necessarily mean vitamin D supplements can reduce the severity of attacks or reduce symptoms.

Researchers and the medical community continue exploring the connection between vitamin D supplements, how they may affect MS symptoms, and their relationship to the condition overall.

Vitamin D is an essential vitamin for everyone.

Attention to vitamin D levels may be even more important for people with MS or at risk for this condition. Some healthcare professionals may advise people with lower vitamin D levels to take supplements if they’re more at risk for MS or replases.

Researchers have long believed there’s a link between low levels of vitamin D and MS risk. But it’s unclear whether direct sunlight affects vitamin D levels or the vitamin D found in the food.

In a 2023 study based in Norway, researchers found that people who consumed vitamin D through food or supplements had a 37% lower risk of developing MS than those who didn’t have that additional vitamin D in their bodies.

But even if vitamin D can affect MS development in those at risk, research does not clearly show that it has any effect on MS relapses, symptoms, or attacks.

This 2023 study sponsored by the National Multiple Sclerosis Society found that higher vitamin D doses, when combined with prescription medication, did not reduce the risk of these happening for people with relapsing-remitting MS.

This echoes the findings of other research, which suggests that there is no clear effect of vitamin D on MS symptoms or the severity of MS attacks.

Researchers have continued to point out that their findings aren’t conclusive. They need more human clinical trial research on this topic.

In general, the benefits of vitamin D remain important to remember for overall health and other conditions that those with MS are more at risk for.

As MS has also been linked to a higher rate of osteoporosis, supplementing with vitamin D may help increase bone health and decrease the risk factors related to developing this condition.

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

Despite the likely link between vitamin D levels and MS risk, researchers are unsure what may be the best way to use vitamin D to treat people who already have the condition.

These levels are not easy to obtain through sunshine and diet alone. You may want to discuss with your healthcare team the need to take vitamin D supplements to reach the recommended levels.

However, there is no consensus on what an “optimal” amount of vitamin D is for reducing MS risk or relieving the symptoms of those who live with the condition.

This 2023 research examined higher doses of vitamin D when combined with other MS therapy. They did not find any benefit in people with the condition.

A 2018 research analysis also pointed out that vitamin D add-on treatments did not have any therapeutic effect on those with the condition.

Citing earlier research, researchers in this 2020 analysis emphasized that using vitamin D supplements for MS treatment can be a “sensitive task” that needs physician guidance. Taking too much vitamin D can lead to side effects and risks, including:

In general, aside from agreeing that vitamin D levels likely relate to MS, researchers agree that more research would help determine how clinicians may best advise people on taking vitamin D supplements as part of their MS care plan.

Consulting your healthcare team is always best before trying vitamin D or other supplements. They can guide you if you have any concerns about changes in your MS symptoms.

Vitamin D sources and supplements

The National Institutes of Health (NIH) recommends the following for vitamin D amounts each day:

  • below the age of 1 year: 400 units (IU) per day
  • ages 1 to 70 years: 600 units per day
  • ages 70 years and older: 800 units each day

Some possible food sources of vitamin D include:

  • fish
  • liver
  • mushrooms
  • eggs

While research points toward a promising trend in reducing MS risk for people more likely to develop the condition, many experts say more research is needed to confirm whether vitamin D can actually help reduce symptoms, MS attacks, or relapses. There is also no clear guidance on the optimal dose of vitamin D for reducing the risk of MS.

Despite the lack of evidence, experts say that vitamin D is safe and inexpensive. Having vitamin D may benefit people with MS in general, especially those who have vitamin D deficiency.