Our Parents
Senior Health
Senior Living Options
Finances & Legal
Products for Seniors
About Us
A pink banner with the OurParents logo

Vitamin B12 and Dementia: What’s the Connection?

Written by Amanda Lundberg
 about the author
11 minute readLast updated June 20, 2023

What if the foods our loved ones consume — or the vitamins they neglect — could silently be influencing their memory and cognitive functions? In particular, vitamin B12, found in various animal products and fortified foods, might be more significant than we realize. As we journey into the intricate web of B12 deficiency, dementia, and the subtle symptoms that could confuse one for the other, we aim to shed light on these interconnected concerns with empathy and clarity.

Key Takeaways

  1. Vitamin B12 can be obtained naturally from various animal products and fortified foods. Most people get enough vitamin B12 through their diet, but some may need a supplement.
  2. Symptoms of B12 deficiency can mimic dementia. This overlap in symptoms should lead to discussions with your loved one’s health care provider about a diagnosis and next steps.
  3. Seniors are at a higher risk of B12 deficiency. Various reasons can inhibit absorption, including stomach inflammation or dietary choices.
  4. The relationship between B12 deficiency and dementia remains under debate. Research has drawn associations between low B12 levels and cognitive deterioration.

What is vitamin B12?

Vitamin B12 plays a significant role in the human body, especially when it comes to nerve cells, brain cells, and DNA.[01] The body is unable to store large amounts of this vitamin obtained through normal dietary means. However, when administered as a high-dose supplement through a monthly injection, usually for those who have difficulty processing the vitamin, the body can store the excess vitamin B12 in the liver for later use.
Vitamin B12 is water-soluble and naturally available in various animal products and fortified foods such as:
  • Beef liver
  • Clams
  • Eggs
  • Fish
  • Milk
  • Nutritional yeasts
  • Poultry
  • Fortified breakfast cereals [03]
Your loved one can also supplement their diet with B12 in forms like methylcobalamin or cyanocobalamin, especially if you’re exploring ways to combat B12 deficiency memory loss in the hope that it’s reversible.[01]

How can B12 deficiency look like dementia?

People with a deficiency in vitamin B12 might show physical and mental signs that could easily be confused with dementia symptoms, such as:
  • Confusion
  • Constipation
  • Feeling down or depressed
  • Fatigue
  • Memory loss
  • Poor balance
  • Sore mouth or tongue
  • Tingling or numbness in hands and feet
  • Weakness
  • Weight loss

Let our care assessment guide you

Our free tool provides options, advice, and next steps based on your unique situation.

As you can see from the above list, some signs of B12 deficiency can be remarkably similar to dementia, including confusion, memory issues, and problems with balance and movement. This is why you might hear people talk about B12 dementia. Yet, it could be that the symptoms of B12 deficiency are just imitating the symptoms of dementia, so be sure to consult with your loved one’s doctor if you suspect their diet may be affecting their cognition.

Are seniors more prone to being deficient in B12?

Most people living in the United States get enough B12 from the food they eat, so they don’t have a deficiency. However, older adults might have a higher chance of not getting enough B12. This is particularly true for older people dealing with long-lasting inflammation in the stomach, such as atrophic gastritis, and those who frequently take proton-pump inhibitors for acid reflux.
The lack of B12 might be more usual among seniors who are vegetarian or vegan because the main sources of B12 are found in animal products. This becomes especially vital when considering the potential connection between vitamin B12 and dementia.[04]
The relationship between B12 deficiency and dementia may exist, although the extent of this connection is under ongoing debate, with supporting evidence being somewhat inconclusive. This controversial connection between B12 and dementia was even highlighted in a Stanford University study conducted in 2021.
Numerous scholarly publications in reputable medical journals draw an association between low levels of vitamin B12 and cognitive deterioration. One 2020 study in the American Journal of Clinical Nutrition found that older adults with low levels of vitamin B12 and high levels of folic acid (another category of B vitamin) scored lower on tests that look for early signs of Alzheimer’s disease and other dementias.
However, there are also studies emphasizing that B12 deficiency doesn’t seem to affect older individuals in terms of cognitive decline, regardless of whether they are diagnosed with Alzheimer’s disease or any other forms of dementia.
Interestingly, cognitive decline due to B12 deficiency appears to be different from the type experienced in Alzheimer’s or other commonly recognized forms of dementia. This discrepancy could potentially explain the conflicting research surrounding the topic of how a B12 deficiency can mimic dementia. Furthermore, questions about whether B12 deficiency memory loss is reversible add another layer to this multifaceted discussion. There is currently no definitive answer if vitamin B12 deficiency memory loss is reversible. However, a study published in the Journal of Neuropsychiatry and Clinical Neuroscience found that “the improvement in mental impairment may be possible only in early stages…”

Talk with a Senior Care Advisor

Our advisors help 300,000 families each year find the right senior care for their loved ones.

Unraveling the connection between vitamin B12 and dementia

Though the relationship between B12 and dementia is characterized by mixed and often unclear research findings, it is evident that we need more comprehensive studies. The implications of a potential dementia association with low levels of vitamin B12 underline the importance of a medical professional’s involvement when there is a suspicion of B12 deficiency.
The connection between vitamin B12 and dementia aside, a deficiency might result in significant damage to the nervous system, thereby leading to numerous health issues. Furthermore, vitamin B12 plays a pivotal role in energy production, as cells in the body rely heavily on B12 for proper functioning. As a result, a deficiency in B12 could trigger a series of negative outcomes throughout the body, emphasizing the potential connections between B12 deficiency, dementia, and overall health.[05]
It’s worth noting that the symptoms of B12 deficiency can take years to surface. This delayed onset is due to the body’s ability to store B12 as it’s consumed. The body can store around 1,000 to 2,000 times the amount of vitamin B12 that one would typically consume in a day.[03] Therefore, it’s important for even consumers to understand the link between B12 and dementia and the potential effects of a deficiency to maintain good health.

Recommended steps for handling suspected vitamin B12 deficiency and signs of dementia

It is recommended to consult with your loved one’s health care team if they exhibit signs of B12 deficiency or symptoms akin to dementia.
Their health care team is likely to conduct a thorough review of your loved one’s medical history and present symptoms. Part of this assessment may include examining a comprehensive list of current medications, as some drugs, like proton pump inhibitors and metformin, might disrupt the absorption of B12. They also might order blood tests or other diagnostic procedures to help identify the root cause of the symptoms associated with cognitive changes. Understanding whether B12 deficiency memory loss is reversible is a key part of this assessment and treatment process.


  1. Cleveland Clinic. (2022, April 25). Vitamin B12 Deficiency.

  2. National Cancer Institute. National Institutes of Health. Water-soluble vitamin definition.

  3. Office of Dietary Supplements. National Institutes of Health. (2021, July 7). Vitamin B12 Fact Sheet for Consumers.

  4. Harvard T.H. Chan School of Public Health. (2023, March). Vitamin B12.

  5. O’Leary, F., & Samman, S. (2010, March). Vitamin B12 in Health and DiseaseNutrients.

Meet the Author
Amanda Lundberg

Amanda Lundberg, RN, has over 10 years’ experience in clinical settings, working extensively with seniors and focusing on wellness and preventative care.

Edited byMarlena Gates

The information contained in this article is for informational purposes only and is not intended to constitute medical, legal or financial advice or create a professional relationship between A Place for Mom (of which OurParents is a trademark) and the reader.  Always seek the advice of your health care provider, attorney or financial advisor with respect to any particular matter and do not act or refrain from acting on the basis of anything you have read on this site.  Links to third-party websites are only for the convenience of the reader; A Place for Mom does not recommend or endorse the contents of the third-party sites.