Everyone knows that vitamins and nutrition are important for health, and many older adults take a multivitamin.
But did you know that even among older persons who do this, many still end up developing a serious deficiency in one particular vitamin?
It’s Vitamin B12.
If there’s one vitamin that I’d like all older adults and family caregivers to know more about, it would be vitamin B12.
(Second on my list would be vitamin D, but it’s much harder to develop low vitamin D levels if you take a daily supplement, as I explain in this post. Whereas vitamin B12 deficiency does develop in many older adults who are getting their recommended daily allowance.)
A deficiency in any vitamin can be catastrophic for health. But vitamin B12 deficiency stands out because a) it’s very common — experts have estimated that up to 20% of older adults may be low in this vitamin — and b) it’s often missed by doctors.
Geriatricians also like to pay attention to vitamin B12 because a deficiency can cause — or usually worsen — cognitive impairment or walking problems.
But if you know the symptoms and risk factors, you can help ensure that you get a vitamin B12 deficiency detected. Treatment is safe and effective, as long as you catch the problem before permanent damage occurs. Here’s what to know.
How Vitamin B12 Deficiency Harms Health
In the body, vitamin B12 – also known as cobalamin — is especially vital to making red blood cells, and maintaining proper function of nerve cells. When vitamin B12 levels are low, a person can develop health problems related to red blood cells and nerve cells malfunctioning.
The most common problems related to low vitamin B12 levels include:
- Anemia. This means the red blood cell count is low. Red blood cells carry oxygen in the blood, so anemia can cause fatigue or shortness of breath. The breakdown of faulty red blood cells can also cause jaundice. (Learn more about anemia here: Anemia in the Older Adult: 10 Common Causes & What to Ask.)
- Neuropathy. This means that nerves in the body are not working well. This can cause a variety of symptoms, including tingling, numbness, burning, poor balance, and walking difficulties.
- Cognitive impairment. This means that nerve cells in the brain are not working well. This can cause memory problems, irritability, and even dementia.
You may have heard that vitamin B12 deficiency can cause pernicious anemia. But in fact, the term “pernicious anemia” means a specific vitamin B12 deficiency caused by the loss of the body’s ability to make “intrinsic factor.” Intrinsic factor is in the lining of the stomach, so a weakened stomach lining (which is called “atrophic gastritis” can cause pernicious anemia. The body needs intrinsic factor to absorb vitamin B12; without it, vitamin B12 levels eventually drop. This often causes anemia, but sometimes symptoms of nerve and brain problems occur first.
Why Low Vitamin B12 Levels Are Common in Older Adults
To understand how low vitamin B12 levels happen in aging adults, it’s good to start by learning how the body usually obtains and processes this vitamin.
In nature, vitamin B12 is available to humans only in meat and dairy products. However, in modern times, you can easily get it via a supplement or multivitamin. The recommended daily allowance for vitamin B12 for adults is 2.4 micrograms. Experts have estimated that a Western diet contains 5-7 micrograms of vitamin B12, and a multivitamin often contains 12-25 micrograms.
Once you ingest vitamin B12, it is processed by acids and enzymes in the stomach and small intestine. The processed vitamin is then absorbed by the small intestine and stored in the body, especially in the liver.
This stash can actually meet the body’s needs for a few years; although vitamin B12 is essential, only a tiny bit is needed every day. So if a healthy person stops taking in vitamin B12, it often takes a few years before the body runs out of it and develops symptoms.
So why does vitamin B12 deficiency particularly affect older adults?
As people get older, their ability to absorb vitamin B12 decreases. This is because aging adults often develop problems with the acids and stomach enzymes needed to process the vitamin.
Common risk factors for low vitamin B12 levels in older adults include:
- Low levels of stomach acid. This can be due to weakening of the stomach lining (also known as “atrophic gastritis”), or to medications that reduce stomach acid.
- Medications such as metformin (used for diabetes), which interferes with vitamin B12 absorption.
- Alcoholism, which irritates the stomach and sometimes is linked to a poor diet.
- Surgeries to remove parts (or all) of the stomach or small intestine.
- Any problem that causes poor absorption in the stomach or small intestine, such as Crohn’s disease.
Why Vitamin B12 Deficiency Is Often Missed in Aging Adults
Vitamin B12 deficiency is often missed because the symptoms – fatigue, anemia, neuropathy, memory problems, or walking difficulties – are quite common in older adults, and can easily be caused by something else.
Also, vitamin B12 deficiency tends to come on very slowly, so people often go through a long period of being mildly deficient. During this time, an older person might have barely noticeable symptoms, or the symptoms might be attributed to another chronic health condition.
Still, a mild deficiency will almost always get worse over time. And even when an older adult has many other causes for fatigue or problems with mobility, it’s good to fix whatever aggravating factors – such as a vitamin deficiency — can be fixed.
Unlike many problems that affect aging adults, vitamin B12 deficiency is quite treatable. Detection is the key; then make sure the treatment plan has raised the vitamin B12 levels and kept them steady.
Who Should Be Checked for Vitamin B12 Deficiency
An older person should probably be checked for Vitamin B12 deficiency if he or she is experiencing any of the health problems that can be caused by low levels of this vitamin.
I especially recommend checking vitamin B12 levels if you’re concerned about memory, brain function, neuropathy, walking, or anemia.
To make sure you aren’t missing a mild vitamin B12 deficiency, you can also proactively check for low vitamin B12 levels if you or your older relative is suffering from any of the common risk factors associated with this condition.
For instance, you can request a vitamin B12 check if you’re vegetarian, or if you’ve suffered from problems related to the stomach, pancreas, or intestine. It’s also reasonable to check the level if you’ve been on medication to reduce stomach acid for a long time.
How Vitamin B12 Deficiency is Diagnosed
The first step in checking for deficiency is a blood test to check the serum level of vitamin B12.
Because folate deficiency can cause a similar type of anemia (megaloblastic anemia, which means a low red blood cell count with overly-large cells), doctors often test the blood for both folate and vitamin B12. However, folate deficiency is much less common.
You should know that it’s quite possible to have clinically low vitamin B12 levels without having anemia. If a clinician pooh-poohs a request for a vitamin B12 check because an older person had a recent normal blood count, you can share this research article with the clinician.
Although MedlinePlus says that “Normal values are 160 to 950 picograms per milliliter (pg/mL)”, the clinical reference UptoDate says that a normal serum vitamin B12 level is above 300 pg/mL.
Normal vitamin B12 levels do not change with age, so there’s no need to look for a different cutoff as people get older.
If the vitamin B12 level is borderline, a confirmatory blood test can be ordered. It involves testing for methylmalonic acid, which is higher than normal when people have vitamin B12 deficiency.
In my own practice, especially if an older person has risk factors for vitamin B12 deficiency, I consider a vitamin B12 level of 200-400 pg/mL borderline, and I usually order a methylmalonic acid level as a follow-up.
How to Treat Vitamin B12 Deficiency in Older Adults
If the blood tests confirm a vitamin B12 deficiency, the doctors will prescribe supplements to get the body’s levels back up. The doctor may also recommend additional tests or investigation to find out just why an older person has developed low vitamin B12.
The usual dosage for initially treating vitamin B12 deficiency in older adults is 1000 micrograms, which can be given as a weekly intramuscular injection, or as a daily oral B12 supplement.
It’s common to start treatment for a significant vitamin B12 deficiency with weekly intramuscular shots (1000 micrograms of vitamin B12). This bypasses any absorption problems in the stomach or intestine, and is a good way to get an older person’s vitamin B12 level back to normal quickly.
High-dose oral vitamin B12 supplements (1000-2000 micrograms per day) have also been shown to raise levels, because high doses can usually compensate for the body’s poor absorption. However, oral treatments probably take longer to work than intramuscular shots. So they’re not ideal for initially correcting a deficiency, although they’re sometimes used to maintain vitamin B12 levels.
I’ve found that most older patients prefer oral supplements over regular vitamin B12 injections, which is understandable; shots aren’t fun. However, this requires the older person to consistently take their supplement every single day. If you (or your older relative) has difficulty taking medications regularly, scheduled vitamin B12 shots are often the better option.
And the good thing about vitamin B12 treatment is that it’s basically impossible to overdose. Unlike some other vitamins, vitamin B12 doesn’t cause toxicity when levels are high.
So if you’re being treated for vitamin B12 deficiency, you don’t need to worry that the doctors will overshoot. You just need to make sure a follow-up test has confirmed better vitamin B12 levels, and then you can work with the doctors to find the right maintenance dose to prevent future vitamin B12 deficiency.
For an older person on vitamin B12 injections, once the blood level of vitamin B12 has normalized, the injections can be given once a month.
Are There Other Benefits To Taking Vitamin B12 Supplements?
Since we know vitamin B12 is necessary for the proper function of red blood cells and brain cells, you might be wondering if it’s good to take higher doses of vitamin B12 as part of a healthy aging approach.
It certainly won’t hurt, since vitamin B12 doesn’t cause problems at higher blood levels the way some vitamins do.
But once an older person has a good level of vitamin B12 in the body, it’s not clear that additional vitamin B12 will reduce the risk of problems like cancer or dementia. To date, much of the research on the benefits of extra vitamin B12 has been inconclusive.
However, research has definitely confirmed that a deficiency in this essential vitamin is harmful to the body and the brain, with worse deficiencies generally causing greater harm.
So to help yourself or a loved one make the most of this vitamin, focus on detecting and treating vitamin B12 deficiency. Remember, this common problem is frequently overlooked.
You can help yourself by asking the doctor to check vitamin B12 if you’ve noticed any related symptoms, or by asking for a proactive check if you have any risk factors.
Older adults often have enough health problems to deal with. Let’s make sure to notice the ones that are easily detectable and treatable.
Have you had any challenges related to vitamin B12 deficiency? I’d love hear from you in the comments below.
Sara says
Hi I’m 31 and been having a few issues I sometimes go to the right when walking like I lose all control of my balance and it regains within a couple of seconds, tingling feeling on the left side of my head like someone is running their hands gently over my head and can feel the nerves on the left side of my face going mad, along with ringing in my ears and a severe pressure on the left side of my temple my hands and feed have started feeling like a tingling sensation along with they feel cold on the outside yet feel warm on the inside if that makes sense I’ve also noticed I have become really irritable with everything and can forget some simple things or even when I’m talking I will forget what I’m talking about, I went to my doctor they done some blood work and it came back b12 deficiency/folate anemia so a second round of bloods where done and I just called up yesterday for results and they said the doctors want to talk to me about my bloods but have prescribed iron and folic acid tablets now my symptoms are closer to the be than the other two how can I ask my doctor if they are sure it isn’t my bqw because as far as I’m aware some folic acid will help but it can worsen the problem of the nerve damage I don’t want it to be misdiagnosed and make the problem actually worse
Nicole Didyk, MD says
Hi Sara. As a Geriatrician, I usually treat those over 65, so a 32 year old is a bit out of my wheelhouse.
The concern with replacing folate without replacing vitamin B12 is that as the folate is replenished and the cellular machinery fires up, Vitamin B12 can be used up quickly, so if it’s deficient as well, that could lead to a sudden worsening of Vitamin B12 deficiency related symptoms. Usually, it’s safe for someone to take Vitamin B12 along with folate and iron, but I would check with your medical team to make sure.
Rita says
Hi, I started having tinnitus one month ago and ENT said there is nothing to do. I read that taking vit B12 at 1000 ug and folic acid will help with tinnitus. Last year check up on vit B12 was double the normal and my dr. said it was ok since I knew that I was taking it purposely for my hand pain problem. So do you suggest I take 500 ir 1000ug if B12 and 400ug of folic acid. Folic acid I read only to take for 4 months. At present I take vit K2 and vit D 4000 cos my vit D is 22. At the same time, my husband has been suffering from tinnitus for 7 years. His vit D and vit B12 are normal. Will it help him to take the same B12 1000ug and folate 400. Thank you. I would appreciate your reply because my dr. just agrees with ENT to live with it.
Nicole Didyk, MD says
Sorry to hear that you’re living with tinnitus. It can be very disabling for some.
There seems to be a higher chance that a person with tinnitus has a B12 deficiency, but I couldn’t find good evidence that replacing B12 fixes the tinnitus. I think taking more B12 is likely safe but I’m convinced it will relieve tinnitus, whether your B12 level is normal or not.
You might be interested in these YouTube videos I made about tinnitus:https://youtu.be/7wcN7PDShUM
Kay Bonnard says
Hi-
Just had the chance to read the article; been saving it to read “later!”
It would be nice for you to proofread your postings to ensure that comments like “ask your doctor to…” aren’t followed by lines like “he may not x-y-z…” There are a lot of women who are doctors. I’d say that the majority of new docs are female.
Nicole Didyk, MD says
Thanks for the suggestion! I know Dr. K meticulously proofreads her work and would appreciate your feedback.
Beth Kashner says
Thank you for this article. I’ll share it with all my older friends. We’ve been checking vitamin D for years.. and I have been on supplements. Last year my doctor checked my B12, (low) folate, and methylmanoic acid., both high. I’m not sure how these three tests relate.. I’ve been taking 1000 mcg of B12 for a year, and now the readings are too high. She said I should cut down to 500. I’m still really tired..though now I have estrogen positive breast cancer and will have to take anastrozole. I have osteopenia, so I’m also taking fosomax. The B 12 should be good for my brain, since I have minor micro vascular disease. I take meds for high cholesterol, high blood pressure, and depression. In spite of all this, I still feel very fit, and the only ailment with symptoms is the depression. Sometimes I wonder what will eventually do me in..maybe getting hit by the proverbial bus.
Nicole Didyk, MD says
I’m so glad you like the article, Beth and I appreciate your sense of humor.
Methylmalonic acid (MMA) and homocysteine are involved in the metabolism of B12, so if B12 is low, less of the MMA is used up and its levels rise. An overly elevated B12 is usually not dangerous, but can be an indication of a “functional” B12 deficiency (there’s lots of B12 but it’s not being taken up by the tissues properly) and can be present with some types of cancer.
I’m glad you describe yourself as fit even though you’re living with some health conditions. Sticking to your medication regimen, eating well, exercising and reducing stress are all good strategies for brain health.
Christine says
Dr Kernisan.
This article could not have come at a better time for me. I am a 71 yo former athlete. I pay attention to my body.
In July I had an episode of significant loss of balance and dizziness not improved by sitting down. An intermittent balance problem had begun about 6 weeks prior, when I walked like I was drunk, with no identifiable cause.
In July, my PCP sent me to the ED to r/o stroke. All clear. F/u visit at provider’s office the next day.
Was seen by a NP who pre -diagnosed me as having “what’s going around — fluid behind the eardrum” and prescribed nasal washes. (Official chart notes indicate tympanic membranes were clear.) She refused to reconsider her “diagnosis.”
I finally realized I no longer have confidence in the Dr’s practice and switched providers. First introductory visit in December.
I have been taking the minimum RDA for all B vitamins plus extra folate for years. Today I am uping my B12 to 1250% RDA.
Questions: 1) Should I request a B12 blood test from new provider? If she declines, should I self-order one (allowed in my state)? I am a retired MT (ASCP).
2) Should I provide my former PCP a letter detailing my unsatisfactory visit with the NP? I had beern very happy with my PCP because she was up-to-date in aging issues.
Thank you.
Nicole Didyk, MD says
Hi Christine and I’m happy this article was helpful for you!
If you had a B12 deficiency before and are wondering if you’re on the right track with replacement, then getting a level checked is a good idea.
I’m sorry you had an unsatisfactory visit with the NP and I can understand wanting to share that information with the physician. It might be worth thinking about your motivation for communication – whether you feel the NP was unethical, incompetent or dangerous (which is a very serious complaint), or if it was more that you were unhappy with her bedside manner, which almost any provider can fail at on occasion. A breach of ethics or incompetence would be very important to report.
Other than that, it’s completely up to you.
Cj says
I do consider her incompetent and a danger to patients who come through that practice.
Your circle-the-wagons response tells me what a waste of effort it would be to give the practice the facts regarding the visit (not whether I like her or don’t).
Nicole Didyk, MD says
As I mentioned in my response, if a patient feels that there’s incompetence and others may be at risk then making a report would be a valuable service to others.
Kathleen Todora says
In recent months my RBC, Hemoglobin, and Hemocrite numbers are dropping. from normal readings over a year to Low. now…..Hemoglobin now 10.3 Hemocrit 30.6 and RBC 3.18…no iron deficiency no occult blood, and diagosed now with anemia I am 87 and doctor said these readings not uncommon for women my age. I trust and like my doctor of the past 3 years, but these usually annual lab tests show descending counts in all three with each test, one annual and the others six months apart the most recent October 2021. No treatment for anemia was recommended….and your article really helped although my B!2 folate was not considered low and my Methymalonic acid serum was 283.
My concern is my body seems to be slowly slipping into low RBC production…I did find a Vegan B12 liquid drops 5000 mcg formula to be taken 500 mcg twice a day and just started this protocol this week, my concern is can B12 reverse the lack of production of Red Blood Cells? My figures had dropped from 12 to 10.3 in 18 months, and I am hoping this B12 treatment will help return these figures to normal? As I am aware of other more serious conditions that anemia can reveal. Thank you for this article!
I forgot to say I am exhausted all the time and am having severe night sweats this past few months.
Nicole Didyk, MD says
Thanks for sharing your story, Kathleen, and I’m glad you enjoyed the article.
If your B12 level was normal, supplementing with B12 will probably not boost your red blood cell production. It’s also not possible to tell from a hemoglobin level alone whether the issue is production of blood cells, blood loss, or something else. Your doctor may have done some other tests to rule out those other processes.
Night sweats are worrisome, though, and if one of my patients starts having these I would want to know about it. Night sweats can be caused by many things, including medications, anxiety, thyroid overactivity, and certain infections or malignant conditions. I would let your doctor know about the sweating if you haven’t already – it may change the investigation and treatment plan.
JERRY RUNNELS says
I receive quarterly blood tests related to my Type 2 diabetes, heart disease and prostate cancer. My PCP told me about 6 months ago that i have Chronic Disease Anemia caused by my underlying conditions. My Cardiologist and Rad Onc told me to work with my PCP on the anemia! I have been taking a Vitamin D 50mcg pill each morning for close to 2 years. My doctor has never mentioned my Vitamin B levels in any of our quarterly meetings. What specific blood test will measure my B12 levels? Should i ask him about my B12 levels or should i simply start taking a B12 daily vitamin? I already take 11 various meds a day but am in good shape, especially for my age..81…and my various serious health problems. I just am not sure my doctors are taking my Chronic Disease Anemia seriously, or are not telling me to just accept it because it wont get better due to my health and co-morbidities. I just completed SBRT in August for my PCa. Thanks so much. Your website is excellent!
Nicole Didyk, MD says
I’m so glad you enjoy the website!
Anemia of chromic disease (ACD) is a common cause of a low hemoglobin in older adults. You can read more about it here: https://www.karger.com/Article/FullText/452104
There are a few different mechanisms that contribute to ACD, including inflammation, impaired iron metabolism and reduced red blood cell production. B12 levels are usually normal in ACD, but some will have more than one cause of anemia.
A blood level of Vitamin B12 (which is the only test that would show your B12 status) is usually ordered as part of the anemia workup, so you may have already had one done.
If taking an additional pill would be burden, I would check to see if it’s been measured before adding it as a supplement.
KSavage says
My eye Dr recommended a new daily dose of B12. It may be related to glaucoma. Do you have any comments?
Nicole Didyk, MD says
I hadn’t heard about this before, but it appears that in glaucoma and some other eye conditions there can be a high level of homocysteine (an amino acid that is linked to oxidative stress and vascular disease) in the blood, and this can be lowered by taking a Vitamin B12 supplement. Here’s an article that describes the reasoning behind that: https://pubmed.ncbi.nlm.nih.gov/24247916/
Vitamin B12 is usually low cost and has few side effects, if any, so it’s reasonable to add.
Laney Ensley says
I’m a 58 year old female who has been experiencing several debilitating symptoms for about 4 weeks. I am very weak, all I want to do is to sleep. My legs feel like rubber bands. My arms, hands, and neck are aching so badly that I can’t function right. I’m sweating profusely like I never have before. I’m extremely short of breath. My doctor advised that I have a B12 deficiency. My question is can this be the sole cause of all the symptoms. The doctor prescribed a monthly injection. However I felt so horrible that I gave myself another injection after a week. I felt better in 30 minutes.
Nicole Didyk, MD says
Those symptoms sound very severe for B12 deficiency. B12 deficiency usually causes anemia, which can make a person feel tired and weak, but pain and shortness of breath is unusual.
I wouldn’t advise my patients to inject themselves with Vitamin B12. Injecting any substance into a muscle can cause infection and other complications.
Lata says
I am 79 year old lady, mostly vegetarian. Feel malaise, tired, fatigue and muscle pain especially in both calves. I was very active but now due to muscle pain and fatigue is hampered.
Doctor has checked blood test including B12, all tests but not told about any deficiency.
Worried about my health.
Please suggest if anything I can do
Nicole Didyk, MD says
That sounds like a frustrating situation, and I see many older adults who limit their physical activity due to symptoms, which leads them to feel worse in the end.
Fatigue is one of those “non-specific” symptoms that can have a number of causes, so I’m not surprised that your doctor took a look at your bloodwork, and I’m glad that the results were reassuring. As usual, I would encourage a review of any medications that may have fatigue as a side effect, and this is usually where I start when I see someone with unexplained tiredness.
Muscle pain, though, could be associated with certain conditions in the muscles or blood vessels. Myositis for example (muscle inflammation), can be caused by some medications (cholesterol lowering pills are one type), but that often also causes swelling and warmth. A blocked artery in the legs can lead to calf pain, especially when the pain comes on during exercise, and gets better with rest.
Persistence can pay off when working with your doctor to sort out a concerning symptom, and unfortunately, it can sometimes take some time to get the answers that you need. I hope you can get some clarity and relief.