Vitamin and mineral supplements are a popular topic among MyMSTeam members, who often discuss which ones they take and which ones might be helpful for multiple sclerosis (MS) symptoms. “Is anyone here taking extra vitamins, and do you think it helps?” one MyMSTeam member asked.

Another member wrote, “I topped up on vitamin D and vitamin B12 today. I feel these vitamins help me with my mobility and mood. 😊”

More than 50 percent of people in the U.S. take some kind of dietary supplement. Although some people with MS report that vitamin supplements help them feel better, it’s important to know the risks of taking vitamins, which may cause side effects or interact poorly with medications that help slow the progression of MS.

Always get medical advice from your health care providers before buying supplements. Here are some facts about vitamins you can discuss with your doctor to help determine if vitamin supplements are right for you.

1. Vitamins Are Necessary Nutrients, but Supplements for MS Need More Evidence

Vitamins and minerals are nutrients that help the body function properly, and a healthy diet can provide most people with the amounts they need. Doctors sometimes recommend supplements for people who are deficient (lacking) in certain vitamins or have particular medical conditions. However, not much evidence supports taking nutritional supplements to improve overall health or prevent disease. According to the National Institutes of Health (NIH), many people do not need vitamin and mineral supplements.

Scientists have been keen on investigating how vitamins contribute to nerve function and inflammation that causes MS. Studies have shown that some vitamins have anti-inflammatory properties and may help relieve MS symptoms such as fatigue and cognitive impairment (problems with thinking and memory). However, most researchers agree that it is not clear how vitamin supplements can support MS treatment. For instance, vitamin B1 may help reduce fatigue, but in higher doses, this nutrient may make some MS medications less effective.

Nonetheless, people with MS have higher rates of deficiency in vitamins A, B12, and D3 than the general population. Your doctor can determine if you are lacking in vitamins and recommend supplements that may be appropriate for you.

2. Vitamin D for MS Has Been Widely Studied, With Mixed Results

Research on vitamin D and its role in MS has attracted a lot of interest in recent years. Your body produces vitamin D when exposed to sunlight, and the nutrient is also found in foods like fatty fish and egg yolks. Because MS occurs more frequently in countries that are farther from the equator, researchers have studied whether low vitamin D levels increase the risk of developing MS. The results don’t provide a clear answer.

A number of studies have looked at the relationship between vitamin D supplements and lower rates of MS disease activity and relapses. Some results do suggest a link between vitamin D deficiency and greater risk of MS, and deficiency may be associated with worse symptoms and signs in people diagnosed with MS. Yet in double-blind, placebo-controlled trials — neither the researchers nor the participants know who is receiving the actual treatment and who is getting an inactive substance — vitamin D supplements don’t seem to benefit most people with MS. Because the data is limited, researchers recommend that further evaluation be done.

Other factors might have you wondering if vitamin D supplements are a good idea for you. For example, the body requires vitamin D for the absorption of calcium, which supports bone health, and supplements are sometimes recommended for people at risk of fractures from osteoporosis. Because of mobility limitations and steroid use, people with MS have an increased risk of osteoporosis, which is one reason they may be advised to take vitamin D supplements.

Studies show high rates of vitamin D deficiency in the general population, and your doctor may determine that a vitamin D supplement is right for you. In a systematic review of studies (a look at all relevant research) of vitamin D and mental health in people with MS, researchers determined that deficiency may be a factor in higher rates of depression among people with MS.

High levels of vitamin D can be toxic, so it’s important to discuss the appropriate dosage with your health care team before taking any supplements.

3. Certain Vitamins May Interfere With Some MS Treatments

High levels of some vitamins and minerals have been shown to reduce the effectiveness of immunosuppressive and immune-modulating drugs that can help reduce disease activity, relapses, and progression of MS. These disease-modifying treatments (DMTs) are designed to inhibit the overactive immune system response that causes damage to nerve fibers in people with MS. Supplements that boost the immune system may counteract these types of drugs, lessening their effects, if dosages are greater than the dietary reference intake (DRI).

Some experts recommend avoiding high-dose supplements of the following vitamins and minerals that may interfere with DMTs:

• Vitamin A
• Certain B vitamins (B1, B2, B6, biotin, and folic acid)
• Selenium
• Zinc
• Magnesium
• Copper
• Manganese

Talk to your neurologist about supplements and drug interactions that may affect you.

4. High Doses of Many Vitamins Have Unwanted Side Effects

Our bodies need very small amounts of vitamins and minerals for healthy cell function. Vitamins and minerals are known as micronutrients, and virtually all of them bring a risk of side effects if taken in large doses.

For instance, vitamin A doses higher than 10,000 international units taken during pregnancy are linked to a higher incidence of birth defects. Vitamin C doses of more than 2,000 milligrams are associated with diarrhea and a risk of kidney damage. Too much vitamin B6 can cause tingling, pain, or numbness.

Side effects from high doses of minerals can also be harmful. Too much iron can cause constipation, abdominal pain, and vomiting. High doses of zinc can lead to a copper deficiency. Excessive calcium may cause kidney stones and can keep your body from properly absorbing other minerals.

Talk to your health care providers about potential side effects of vitamins and minerals, as well as recommended dosages for each supplement.

5. The FDA Doesn’t Strictly Regulate Vitamins and Other Supplements

It’s important to be aware that the U.S. Food and Drug Administration (FDA) has limited authority over nutritional supplements such as vitamins and minerals that are sold in the United States. Unlike drugs, vitamins are not required to be tested in clinical trials and in-depth studies before they are available to the public.

The FDA doesn’t regulate supplements for effectiveness or safety or oversee how these products are labeled. However, supplement labels do have to list ingredients and provide other basic information.

Keep in mind that supplement ingredients may include additives that are known to be unhealthy, such as artificial colors and fillers like hydrogenated oils. Always read the ingredients list carefully, and talk to your doctor about any components you do not recognize.

After a supplement is released to the public, the FDA is authorized to monitor the manufacturing facilities and review labels and claims about health benefits. The FDA also reviews complaints about supplements and can take action to recall or remove supplements that are found to be dangerous.

6. Vitamins Can Cost a Lot

In the U.S. alone, people spend more than $21 billion each year on vitamin and mineral supplements, according to the NIH. These products can be a considerable expense for an individual.

Before you buy vitamins for MS, be sure to talk with your doctor. Find out whether supplements are warranted for you and what would be an appropriate dose. Let your doctor know if you are taking a multivitamin or any other supplements. Your doctor may recommend a blood test to see if you are deficient in any vitamins.

Your doctor can also advise you on a healthy diet or refer you to a dietitian to be sure you are getting the nutrients you need.

Find Your Team

MyMSTeam is the social network for people with multiple sclerosis and their loved ones. On MyMSTeam, more than 195,000 members come together to ask questions, give advice, and share their stories with others who understand life with multiple sclerosis.

Do you have questions about vitamin and mineral supplements for MS? Have you been evaluated for vitamin deficiencies? Share your experience in the comments below, or start a conversation by posting on your Activities page.