Table of ContentsView AllTable of ContentsB12 and the Nervous SystemCan B12 Help Manage MS?Causes of Vitamin B12 DeficiencyDiagnosis of B12 DeficiencyTreating B12 Deficiency
Table of ContentsView All
View All
Table of Contents
B12 and the Nervous System
Can B12 Help Manage MS?
Causes of Vitamin B12 Deficiency
Diagnosis of B12 Deficiency
Treating B12 Deficiency
Avitamin B12 deficiencycan cause neurological symptoms thatmimicthose ofmultiple sclerosis(MS). Symptoms of both conditions include muscle weakness, difficulty walking, cognitive dysfunction, and sensory disturbances.
Vitamin B12, clinically known as cobalamin or, sometimes, cyanocobalamin, is a water-soluble micronutrient that, among other things, is important to the normal function of the nervous system. Because of this role, it’s been hypothesized that in some cases a deficiency of vitamin B12 may be linked to MS, although this theory is controversial.
Researchers are looking into whether there is a definitive link between B12 deficiency and multiple sclerosis. Regardless of these findings, low levels of B12 are associated with symptoms and health issues, so it’s important to understand how it supports the brain and spinal cord.It’s also a good reason to make sure you’re getting enough of the vitamin in your diet.
This article discusses how vitamin B12 can affect your nervous system and whether it can help manage MS. It also covers the symptoms of vitamin B12 deficiency and what can cause it.
Vitamin B12 Deficiency and the Nervous System
Vitamin B12 plays a key role in helping to maintain myelin—the sheath, or layer, of protein and fatty material that surrounds nerves, including those in the brain andspinal cord. It’s the myelin sheath around individual nerve cells that insulates them and makes it possible for electrical signals to be transmitted quickly and efficiently.
MS is also a disease that affects the myelin sheath of the nerves in the brain and spinal cord. It’s easy to see, then, why a deficiency of B12 can cause MS-like symptoms such as:
Despite this similarity, vitamin B12 deficiency and multiple sclerosis differ in significant ways.
B12 DeficiencyAffects central and peripheral nervous systemsEarly symptoms (numbness, tingling) that may progress to muscle weakness and gait unsteadinessMore likely affects legs rather than armsAffects both sides of the body equallyMore common in middle-age or elderly individualsCan be diagnosed with simple blood testOn an MRI, the brain or spinal cord appear normalMay cause other problems, such as anemia and glossitis (in which the tongue becomes swollen and painful)Multiple SclerosisAffects mostly the central nervous systemEarly symptoms manifest and progress in a variety of ways that are unpredictableDoesn’t impair one body part more than anotherMay be unilateral (affect only one side of the body)More common in people in their 20s or 30sDifficult to diagnose; requires multiple exams and testsIn most cases, an MRI will show lesions on brain or spinal cordNot associated with any co-existing conditions
B12 DeficiencyAffects central and peripheral nervous systemsEarly symptoms (numbness, tingling) that may progress to muscle weakness and gait unsteadinessMore likely affects legs rather than armsAffects both sides of the body equallyMore common in middle-age or elderly individualsCan be diagnosed with simple blood testOn an MRI, the brain or spinal cord appear normalMay cause other problems, such as anemia and glossitis (in which the tongue becomes swollen and painful)
Affects central and peripheral nervous systems
Early symptoms (numbness, tingling) that may progress to muscle weakness and gait unsteadiness
More likely affects legs rather than arms
Affects both sides of the body equally
More common in middle-age or elderly individuals
Can be diagnosed with simple blood test
On an MRI, the brain or spinal cord appear normal
May cause other problems, such as anemia and glossitis (in which the tongue becomes swollen and painful)
Multiple SclerosisAffects mostly the central nervous systemEarly symptoms manifest and progress in a variety of ways that are unpredictableDoesn’t impair one body part more than anotherMay be unilateral (affect only one side of the body)More common in people in their 20s or 30sDifficult to diagnose; requires multiple exams and testsIn most cases, an MRI will show lesions on brain or spinal cordNot associated with any co-existing conditions
Affects mostly the central nervous system
Early symptoms manifest and progress in a variety of ways that are unpredictable
Doesn’t impair one body part more than another
May be unilateral (affect only one side of the body)
More common in people in their 20s or 30s
Difficult to diagnose; requires multiple exams and tests
In most cases, an MRI will show lesions on brain or spinal cord
Not associated with any co-existing conditions
Even though vitamin B12 deficiency and multiple sclerosis are different conditions, they can co-exist. In fact, there has been research to suggest that people with MS are more likely to have a deficiency of B12 than are those who are otherwise healthy.
1:34Myelin Sheath and the Role It Plays in MS
1:34
Myelin Sheath and the Role It Plays in MS
This doesn’t mean, however, that there’s a link between B12 deficiency and multiple sclerosis. In fact, in a 2020 meta-analysis published inInternational Journal of Medical Sciences,researchers were not able to find such a connection.
However, some research has found evidence that supplementation of vitamin B12, often along with another B vitamin, folate (B9), may help to alleviate some symptoms of the disease.
After two months, blood samples were taken from all participants; each person also completed a questionnaire designed to measure quality of life in people living with MS.
B12 Shots: Goal of Injectable Vitamin B
More importantly, the supplement group had an improvement in both physical and mental quality of life. (The placebo group also had significant improvement in mental quality of life.)
By no means does this study (and a few others with similar findings) prove taking B12 will help with the management of MS. However, it clearly is an indication that more research is needed.
Can You Have Too Much B12?
Vitamin B12 is found in dairy products, eggs, meat, chicken, shellfish, and fortified foods. People who are vegan or who follow a very strict vegetarian diet can be at risk of developing a B12 deficiency simply because they don’t consume enough natural food sources of the vitamin.
Other reasons for vitamin B12 deficiency include:
Taking certain medications known to affect vitamin B12 levels. Common examples include the diabetes medicationmetforminand medications used to treat heartburn known asproton pump inhibitorsConditions that interfere with the absorption of nutrients, such asceliac diseaseandCrohn’s diseaseBariatric surgery (such asgastric sleeve surgery) for weight loss, which has been found to affect how nutrients are absorbedPernicious anemia, a condition in which a person cannot properly absorb vitamin B12 from foods because they lackintrinsic factor, a protein produced in the stomach
If your vitamin B12 levels are on the low side of normal, your healthcare provider may order two more blood tests: homocysteine and methylmalonic acid. These metabolic substances are both elevated in vitamin B12 deficiency.
Although this is the most typical way to diagnose B12 deficiency, other tests may be used, includingmagnetic resonance imaging (MRI)of the spinal cord (to look for a bright signal in the posterior part of the cord), or somatosensory or visual evoked potentials.
Steps to Getting an MS Diagnosis
Since B12 is readily available in common foods, dietary changes may be enough to bring blood levels up to normal. A simple approach to turning around a deficiency would be to eat more B12-rich foods, such as clams, beef liver, certain varieties of fish, and fortified nutritional yeast or cereals.
Therecommended dietary allowanceof vitamin B12 for teens and adults 14 and up is 2.4 mcg. Women who are pregnant are advised to get 2.6 mcg of B12 each day, and those who are breastfeeding are advised to get even more—2.8 mcg.
Someone who is found to be deficient in B12 may need to take oral supplements of the vitamin or receive it via intramuscular injections. It can take some time, and in many cases, lifelong supplementation, to bring blood levels of vitamin B12 to normal and keep them there.
A Word From Verywell
The jury is still out about the association between vitamin B12 deficiency and multiple sclerosis, as well as whether B12 supplements can help alleviate MS symptoms.
What cannot be disputed, however, is that eating a well-balanced diet that includes ample vitamin B12 is a smart move for anyone who’s dealing with any chronic health problem or who’s healthy overall and wants to do everything possible to stay that way.
And whichever category you fall into, if you develop symptoms that suggest either MS or a B12 deficiency, see your healthcare provider. Having your levels checked is easy.
15 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.University of Rochester Medical Center.Multiple sclerosis.Harvard Health Publishing, Harvard Medical School.Vitamin B12 deficiency can be sneaky and harmful.Nemazannikova N, Mikkelsen K, Stojanovska L, Blatch GL, Apostolopoulos V.Is there a link between vitamin b and multiple sclerosis?MC. 2018;14(2). doi:10.2174/1573406413666170906123857Johns Hopkins Medicine.Vitamin B12 deficiency anemia.Nemazannikova N, Mikkelsen K, Stojanovska L, Blatch GL,Apostolopoulos V. Is there a link between vitamin B and multiple sclerosis?Medicinal Chemistry. 2018;14(2):170-180. doi:10.2174/1573406413666170906123857Pandey S, V Holla V, Rizvi I, Qavi A, Shukla R.Can vitamin B12 deficiency manifest with acute posterolateral or posterior cord syndrome?Spinal Cord Ser Cases. 2016;2(1):16006. doi:10.1038/scsandc.2016.6National MS Society.Vitamins, minerals and herbs in MS.Li X, Yuan J, Han J, Hu W.Serum levels of homocysteine, vitamin B12 and folate in patients with multiple sclerosis: An updated meta-analysis.Int J Med Sci. 2020;17(6):751-761. doi:10.7150/ijms.42058Nozari E, Ghavamzadeh S, Razazian N.The effect of vitamin B12 and folic acid supplementation on serum homocysteine, anemia status and quality of life of patients with multiple sclerosis.Clin Nutr Res. 2019;8(1):36-45. doi:10.7762/cnr.2019.8.1.36National Institutes of Health, Office of Dietary Supplements.Vitamin B12 fact sheet for health professionals.Miller JW.Proton pump inhibitors, H2-receptor antagonists, metformin, and vitamin b-12 deficiency: Clinical implications.Adv Nutr.2018 Jul 1;9(4):511S-518S. doi:10.1093/advances/nmy023National Library of Medicine.Malabsorption Syndromes.Lupoli R, Lembo E, Saldalamacchia G, Avola CK, Angrisani L, Capaldo B.Bariatric surgery and long-term nutritional issues.World J Diabetes. 2017 Nov 15;8(11):464-474. doi:10.4239/wjd.v8.i11.464The Trustees of the University of Maryland.Pernicious Anemia.Multiple Sclerosis Trust.Vitamin B12.Additional ReadingDardiotis E, Arseniou S, Sokratous M, et al.Vitamin B12, folate, and homocysteine levels and multiple sclerosis: A metaanalysis.Multiple Sclerosis and Related Disorders.2017;17:190-197. doi:10.1016/j.msard.2017.08.004Fahmy EM, Elfayoumy NM, Abdelalim AM, Sharaf SA aaty, Ismail RS, Elshebawy H.Relation of serum levels of homocysteine, vitamin B12 and folate to cognitive functions in multiple sclerosis patients.International Journal of Neuroscience. 2018;128(9):835-841.doi:10.1080/00207454.2018.1435538Oliveira SR, Flauzino T, Sabino BS, et al.Elevated plasma homocysteine levels are associated with disability progression in patients with multiple sclerosis.Metab Brain Dis. 2018;33(5):1393-1399. doi: 10.1007/s11011-018-0224-4
15 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.University of Rochester Medical Center.Multiple sclerosis.Harvard Health Publishing, Harvard Medical School.Vitamin B12 deficiency can be sneaky and harmful.Nemazannikova N, Mikkelsen K, Stojanovska L, Blatch GL, Apostolopoulos V.Is there a link between vitamin b and multiple sclerosis?MC. 2018;14(2). doi:10.2174/1573406413666170906123857Johns Hopkins Medicine.Vitamin B12 deficiency anemia.Nemazannikova N, Mikkelsen K, Stojanovska L, Blatch GL,Apostolopoulos V. Is there a link between vitamin B and multiple sclerosis?Medicinal Chemistry. 2018;14(2):170-180. doi:10.2174/1573406413666170906123857Pandey S, V Holla V, Rizvi I, Qavi A, Shukla R.Can vitamin B12 deficiency manifest with acute posterolateral or posterior cord syndrome?Spinal Cord Ser Cases. 2016;2(1):16006. doi:10.1038/scsandc.2016.6National MS Society.Vitamins, minerals and herbs in MS.Li X, Yuan J, Han J, Hu W.Serum levels of homocysteine, vitamin B12 and folate in patients with multiple sclerosis: An updated meta-analysis.Int J Med Sci. 2020;17(6):751-761. doi:10.7150/ijms.42058Nozari E, Ghavamzadeh S, Razazian N.The effect of vitamin B12 and folic acid supplementation on serum homocysteine, anemia status and quality of life of patients with multiple sclerosis.Clin Nutr Res. 2019;8(1):36-45. doi:10.7762/cnr.2019.8.1.36National Institutes of Health, Office of Dietary Supplements.Vitamin B12 fact sheet for health professionals.Miller JW.Proton pump inhibitors, H2-receptor antagonists, metformin, and vitamin b-12 deficiency: Clinical implications.Adv Nutr.2018 Jul 1;9(4):511S-518S. doi:10.1093/advances/nmy023National Library of Medicine.Malabsorption Syndromes.Lupoli R, Lembo E, Saldalamacchia G, Avola CK, Angrisani L, Capaldo B.Bariatric surgery and long-term nutritional issues.World J Diabetes. 2017 Nov 15;8(11):464-474. doi:10.4239/wjd.v8.i11.464The Trustees of the University of Maryland.Pernicious Anemia.Multiple Sclerosis Trust.Vitamin B12.Additional ReadingDardiotis E, Arseniou S, Sokratous M, et al.Vitamin B12, folate, and homocysteine levels and multiple sclerosis: A metaanalysis.Multiple Sclerosis and Related Disorders.2017;17:190-197. doi:10.1016/j.msard.2017.08.004Fahmy EM, Elfayoumy NM, Abdelalim AM, Sharaf SA aaty, Ismail RS, Elshebawy H.Relation of serum levels of homocysteine, vitamin B12 and folate to cognitive functions in multiple sclerosis patients.International Journal of Neuroscience. 2018;128(9):835-841.doi:10.1080/00207454.2018.1435538Oliveira SR, Flauzino T, Sabino BS, et al.Elevated plasma homocysteine levels are associated with disability progression in patients with multiple sclerosis.Metab Brain Dis. 2018;33(5):1393-1399. doi: 10.1007/s11011-018-0224-4
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
University of Rochester Medical Center.Multiple sclerosis.Harvard Health Publishing, Harvard Medical School.Vitamin B12 deficiency can be sneaky and harmful.Nemazannikova N, Mikkelsen K, Stojanovska L, Blatch GL, Apostolopoulos V.Is there a link between vitamin b and multiple sclerosis?MC. 2018;14(2). doi:10.2174/1573406413666170906123857Johns Hopkins Medicine.Vitamin B12 deficiency anemia.Nemazannikova N, Mikkelsen K, Stojanovska L, Blatch GL,Apostolopoulos V. Is there a link between vitamin B and multiple sclerosis?Medicinal Chemistry. 2018;14(2):170-180. doi:10.2174/1573406413666170906123857Pandey S, V Holla V, Rizvi I, Qavi A, Shukla R.Can vitamin B12 deficiency manifest with acute posterolateral or posterior cord syndrome?Spinal Cord Ser Cases. 2016;2(1):16006. doi:10.1038/scsandc.2016.6National MS Society.Vitamins, minerals and herbs in MS.Li X, Yuan J, Han J, Hu W.Serum levels of homocysteine, vitamin B12 and folate in patients with multiple sclerosis: An updated meta-analysis.Int J Med Sci. 2020;17(6):751-761. doi:10.7150/ijms.42058Nozari E, Ghavamzadeh S, Razazian N.The effect of vitamin B12 and folic acid supplementation on serum homocysteine, anemia status and quality of life of patients with multiple sclerosis.Clin Nutr Res. 2019;8(1):36-45. doi:10.7762/cnr.2019.8.1.36National Institutes of Health, Office of Dietary Supplements.Vitamin B12 fact sheet for health professionals.Miller JW.Proton pump inhibitors, H2-receptor antagonists, metformin, and vitamin b-12 deficiency: Clinical implications.Adv Nutr.2018 Jul 1;9(4):511S-518S. doi:10.1093/advances/nmy023National Library of Medicine.Malabsorption Syndromes.Lupoli R, Lembo E, Saldalamacchia G, Avola CK, Angrisani L, Capaldo B.Bariatric surgery and long-term nutritional issues.World J Diabetes. 2017 Nov 15;8(11):464-474. doi:10.4239/wjd.v8.i11.464The Trustees of the University of Maryland.Pernicious Anemia.Multiple Sclerosis Trust.Vitamin B12.
University of Rochester Medical Center.Multiple sclerosis.
Harvard Health Publishing, Harvard Medical School.Vitamin B12 deficiency can be sneaky and harmful.
Nemazannikova N, Mikkelsen K, Stojanovska L, Blatch GL, Apostolopoulos V.Is there a link between vitamin b and multiple sclerosis?MC. 2018;14(2). doi:10.2174/1573406413666170906123857
Johns Hopkins Medicine.Vitamin B12 deficiency anemia.
Nemazannikova N, Mikkelsen K, Stojanovska L, Blatch GL,Apostolopoulos V. Is there a link between vitamin B and multiple sclerosis?Medicinal Chemistry. 2018;14(2):170-180. doi:10.2174/1573406413666170906123857
Pandey S, V Holla V, Rizvi I, Qavi A, Shukla R.Can vitamin B12 deficiency manifest with acute posterolateral or posterior cord syndrome?Spinal Cord Ser Cases. 2016;2(1):16006. doi:10.1038/scsandc.2016.6
National MS Society.Vitamins, minerals and herbs in MS.
Li X, Yuan J, Han J, Hu W.Serum levels of homocysteine, vitamin B12 and folate in patients with multiple sclerosis: An updated meta-analysis.Int J Med Sci. 2020;17(6):751-761. doi:10.7150/ijms.42058
Nozari E, Ghavamzadeh S, Razazian N.The effect of vitamin B12 and folic acid supplementation on serum homocysteine, anemia status and quality of life of patients with multiple sclerosis.Clin Nutr Res. 2019;8(1):36-45. doi:10.7762/cnr.2019.8.1.36
National Institutes of Health, Office of Dietary Supplements.Vitamin B12 fact sheet for health professionals.
Miller JW.Proton pump inhibitors, H2-receptor antagonists, metformin, and vitamin b-12 deficiency: Clinical implications.Adv Nutr.2018 Jul 1;9(4):511S-518S. doi:10.1093/advances/nmy023
National Library of Medicine.Malabsorption Syndromes.
Lupoli R, Lembo E, Saldalamacchia G, Avola CK, Angrisani L, Capaldo B.Bariatric surgery and long-term nutritional issues.World J Diabetes. 2017 Nov 15;8(11):464-474. doi:10.4239/wjd.v8.i11.464
The Trustees of the University of Maryland.Pernicious Anemia.
Multiple Sclerosis Trust.Vitamin B12.
Dardiotis E, Arseniou S, Sokratous M, et al.Vitamin B12, folate, and homocysteine levels and multiple sclerosis: A metaanalysis.Multiple Sclerosis and Related Disorders.2017;17:190-197. doi:10.1016/j.msard.2017.08.004Fahmy EM, Elfayoumy NM, Abdelalim AM, Sharaf SA aaty, Ismail RS, Elshebawy H.Relation of serum levels of homocysteine, vitamin B12 and folate to cognitive functions in multiple sclerosis patients.International Journal of Neuroscience. 2018;128(9):835-841.doi:10.1080/00207454.2018.1435538Oliveira SR, Flauzino T, Sabino BS, et al.Elevated plasma homocysteine levels are associated with disability progression in patients with multiple sclerosis.Metab Brain Dis. 2018;33(5):1393-1399. doi: 10.1007/s11011-018-0224-4
Dardiotis E, Arseniou S, Sokratous M, et al.Vitamin B12, folate, and homocysteine levels and multiple sclerosis: A metaanalysis.Multiple Sclerosis and Related Disorders.2017;17:190-197. doi:10.1016/j.msard.2017.08.004
Fahmy EM, Elfayoumy NM, Abdelalim AM, Sharaf SA aaty, Ismail RS, Elshebawy H.Relation of serum levels of homocysteine, vitamin B12 and folate to cognitive functions in multiple sclerosis patients.International Journal of Neuroscience. 2018;128(9):835-841.
doi:10.1080/00207454.2018.1435538
Oliveira SR, Flauzino T, Sabino BS, et al.Elevated plasma homocysteine levels are associated with disability progression in patients with multiple sclerosis.Metab Brain Dis. 2018;33(5):1393-1399. doi: 10.1007/s11011-018-0224-4
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