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.
Mary Ann says
My B12 level is 220 and a supplement was advised. I have tried a couple different supplements but they give me heart palpitations. I do not have a heart problem but I can not understand why this occurs. I always stop the supplement because of this symptom.
Please Advise.
Thank you
Leslie Kernisan, MD MPH says
Hm, I’m not sure why this would be happening. I would recommend working with your doctor to evaluate the palpitations and see if you can find another way to treat the vitamin B12 level. You could potentially consider injections?
Jo says
Hello
Your article was very informative.
I was diagnosed as having low levels of B12 and given a course of 100 mg, tested again and the levels were fine. The doctor has said I no longer need supplements and no mention of any future checks.
Is this right “I am cured?”
Nicole Didyk, MD says
I’m glad to hear that your most recent lab work was reassuring.
It really depends on the cause of your B12 deficiency whether you need long-term replacement. For example, if it was related to a diet that was low in B12, and that’s been modified, then you probably don’t to continue with a supplement. It would be reasonable to stop your B12 if that’s what your doctor advised and check a B12 level again in a few months.
Brenda says
I have read in several articles about the need of stopping B 12 supplements 3 -6wks prior to testing as it seems laboratories only test circulating levels, so they are incorrect if recent supplements given. Id say you are not ‘cured’ but ask for a repeat within 3months or just happily take the supplement
Leslie Kernisan, MD MPH says
We usually do not tell people to stop B12 supplements before testing them. Also, the methylmalonic acid confirmatory test should still be able to identify whether the body is feeling deficient or not.
Bernice says
If you suspect a b12 deficiency (vegan, tingling, muscle twitching, dizziness, stiff hands) and start supplementing with 2,000 mcg b12 for 2 months on your own, and then finally get a doctor to do a b12 and mma test, should you hold off on the b12 to get a more accurate picture of what’s been happening? And how long should you hold the b12? Does the body start storing b12 in the liver again if it’s been depleted due to a long term vegan/vegetarian diet? Also is a serum mma test just as good as a urine mma for detecting deficiency?
Thank you.
Nicole Didyk, MD says
I wouldn’t advise stopping your B12 supplement, but if you want to, probably stopping for a few months before the test would be adequate.
If you get your B12 and MMA checked while taking an oral B12 supplement, and your level of B12 is low, that might indicate that the problem is B12 absorption, which might be helpful.
B12 stores become replete fairly quickly, within days, and the effects of B12 deficiency can improve within days or months, depending on the issue. Anemia due to B12 deficiency can take a month or more to correct: https://www.mayoclinic.org/diseases-conditions/vitamin-deficiency-anemia/symptoms-causes/syc-20355025
We usually test serum MMA instead of urine MMA and I didn’t find any information to say that one is better than the other.
Sravani Anandala says
My Sister is 28 years old, she is married and she has vitamin D3 and B12 deficiency.
As per report she has 86 B12.
she has savior leg pains, weakness, headache depression…etc.,
She is breastfeeding, please suggest can she overcome the problem and how long will it take to recover.
from past one month she is taking injections and medicines for deficiency.
I am feeling bed sad about her condition 🙁
Please provide us your valuable reply.
Nicole Didyk, MD says
It sounds like you’re a very thoughtful and compassionate sibling. The symptoms you describe can be related to B12 deficiency, but can also be due to a number of other causes, so I’m glad your sister has seen her doctor about this.
When a vitamin deficiency is fully corrected, and there is no other medical issue, a person can have improvement in symptoms after weeks to months. If things aren’t getting better, it’s a good idea to go back to the doctor to see if any other tests are needed.
Best of luck!
Vicky K says
Hello – after getting Covid in December of 2020, I never started feeling better. My primary care doctor referred me to the Long Haul Covid Clinic. I was seen by many specialists including GI.
At 50 years old, I was diagnosed with Pernicious Anemia, Autoimmune Metaplastic Atrophic Gastritis, and Small Intestinal Bacterial Overgrowth.
My B12 was “almost undetectable” per the GI doctor. She started me on B12 injections because after all the tests, she felt my body would not absorb oral B12.
August 2021 we started off with daily injections for two weeks, then an injection every other day for a week, next was an injection twice a week for a week, down to one injection a week for two weeks, and finally one injection a month. I’d say by week two and three I felt better, not 100%, but better. And then I wasn’t feeling better anymore. I wasn’t worse but I felt I was definitely back to where we started. I talked to GI about it and they ordered bloodwork to be done one week before my next injection. So, one week before and six months after starting the injections, my lab work said my B12 was 430. GI was happy with that number because it is the “normal” range. I’m miserable. Some days I’m so miserable I can’t get out of bed. And now, my husband and I are about to be grandparents for the first time! I don’t want to miss this….we have worked our whole lives to enjoy this new chapter.
Do I need to see a different type of doctor? Is there special doctors that specialize in my specific issues? Do I push for my GI to at least try increasing my B12 does? Can you give me your thoughts, please?
I am at such a loss with all of this. Honestly, all I got education wise, we’ll start antibiotics for SIBO and put you on B12 injections…you’ll start feeling better….it could take a few weeks to a couple of months. That’s it.
Nicole Didyk, MD says
Congratulations on becoming grandparents!
It sounds like you’ve had a lot on your medical plate in the past couple of years, and it would be understandable that your recovery may take longer than you’d like. One would also have to wonder if the long COVID symptoms could be a part of the picture as well.
When B12 levels are normal, it’s not clear that a higher dose would make a difference. Some people with SIBO need more than one course of antibiotics, need to change their diet (no dairy, or even more intense changes, like a liquid elemental diet), or review medications to make sure there isn’t a drug that’s causing the SIBO to persist.
I don’t think another specialist would help, unless it’s a registered dietician to give you advice about how to eat well with SIBO.
Best of luck and enjoy your new grandchild!
Juanita Wigley says
2021 was a year of discovery; a meginomia behind my ear, admomea on the adrenal gland, multiple bone & muscle problems, panic & anxiety attacks and 2 very tiny admomea on my liver. I’m 82 thought I was doing pretty good for the shape I was in; until hopped on the Medical Merry-go-round just as I heard my knees go crack. Anyway, my question? B12 for tinnitus, also for adrenal gland. I am on meds for thyroid, HBP, seizures, hlc, asthma/allergy, nerve pain, seratonin, acid reflux. I was taking d, c and magnesium . Thankfully, none of my tumors are maglinant.
Nicole Didyk, MD says
I’m glad you’re looking on the positive side, Juanita! You’ve had quite a year.
From what I could find, Vitamin B12 has been considered as a treatment for tinnitus, but the evidence isn’t strong that it will help. This article looked at micronutrients and tinnitus and actually, Manganese deficiency seems to have some relationship: https://doi.org/10.1016/j.amjoto.2022.103460
Of course, if a person with tinnitus needs to take Vitamin B12 for some other reason, they should go ahead and take it.
Mike_M says
Thanks for a useful summary of vitamin b12 deficiency, for which I have just started a course of oral boosters. My GP tested for this after my continued concerns about lethargy and sluggish mental processes.
You mentioned that it is difficult to go too far in treating this condition as excess B12 is easily jettisoned. I’m sure, however, that I read somewhere that larger intakes of B12 cause the body to reduce its absorption rate thus reducing or even negating the benefits of supplements.
Have you seen similar reports yourself?
Nicole Didyk, MD says
Vitamin B12 is water soluble so if too much is consumed, it is usually just excreted in the urine. I have read that very high doses can worsen acne or rosacea. Otherwise, B12 is very safe to take, and most people get adequate replacement with a daily dose of about 1 mg.
Best of luck with your B12 treatments.
Kushagra says
Hi, i am 24 years old.
I feel tickling and burning sensation in my hands and legs so I had done a vitamin B12 test and it’s 200 pg/ml ,which is borderline so is that the reason for my problem?
Nicole Didyk, MD says
B12 deficiency can cause numbness or tingling in the hands and feet. A borderline level may not be sever enough to cause those symptoms, so if you replenish your B12 and still have symptoms, I would follow up with your doctor to see if something else is wrong.
Jamal Salem Aljifri - Aden, South Yemen WhatsApp +967 739510383 says
A friend of mine, he was taking orally 500 mcg of vitamin B12 (Methylcoblamine) for 5 months, his vitamin B12 blood test indicated more than 2,000 pg/mL. which is considered too much high, now he is totally too much afraid. He is experiencing loss of appetite, numbness and tingling in the left hand and arm in addition to sleeping disorders. Do you think tbese symptoms caused by high level of vitamin B12 in his serum.
What he should do now and wbat do you recommend. Thank you.
Nicole Didyk, MD says
Hello. 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.
The symptoms you describe could be related to a number of disorders, like depression, thyroid disease, and many other causes. I’m not sure Vitamin B12 is the issue here and it’s probably worth another visit to the doctor.
Jamal Salem Aljifri - Aden, South Yemen WhatsApp +967 739510383 says
Thanks for your quick response, and sorry for disturbing you once again. But, I just now read from book, Could It Be
B-12 that B12, test measures the level of vitamin B12 in blood serum. It’s cheap and easy, but it has three major drawbacks. The first one is that because this test measures inactive as well as biologically active B12, it can yield falsely high results when levels of active B12 are actually low. Do you think the high level of his B12 which is shown more than 2000 pg/mL incorrect.
Thank you very much indeed for your great support.
Jamal
Nicole Didyk, MD says
You’re most welcome!
I did find this letter that reports a case of a falsely elevated Vitamin B12 level: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6614102/. In this report, the patient had a low B12, due to pernicious anemia, but the levels came back falsely elevated.
It would be necessary to know what type of test was used in your friend’s case to say whether this could be what happened.
Jamal Salem Aljifri - Aden, South Yemen WhatsApp +967 739510383 says
Hey
The type of test was used in my friend’s case is only vitamin B12 blood test, I mean the simple and the cheapest one.
Tracey Bevan says
Hiya
I’ve been diagnosed with Chronic Fatigue Syndrome and also have a vit d deficiency. Just recently my joints have become really sore, my balance is all over the place (I have to hold the wall when walking along sometimes), my feet don’t feel like my own and my memory is shockingly bad. I’ve left food in the oven because I forgot I’ve put it in there, I’ve forgotten how to do things on the computer at work. I was so worried I went to the drs and they did a full blood test which came back with only a b12 dificency (good in someways). They put me on a course of three tablets a day for 4 weeks to see if that would bring it back up and I would then have another test to check. I did this and have been told the tablets have worked so I now don’t need to take anything?!?!?! I’m completely confused because surely my b12 will just go back down again. NONE of my symptoms have changed, I feel so tired. I don’t know what to do?
Nicole Didyk, MD says
Hmmm. I don’t have a lot of experience in treating Chronic Fatigue syndrome, but I can tell you that hen someone has a low B12 level, they usually need to take a supplement for the long-term, unless the deficiency was due to some kind of diet issue that can be corrected.
The symptoms you describe could be related to a number of other conditions, and I would advise someone in your situation to continue to advocate for some answers to your questions.
Jerry says
Due to several serious health problems i receive complete panel blood test every quarter. Which specific test is the one which indicates problems with B12 deficiency? I cant find one in my latest test report. I have no idea whether or not i have a B12 deficiency but i do have Chronic Disease Anemia so it may be a possibility. I do have a Vitamin D defiency and take a 2000 Unit Vit D pill every day. Thank you.
Leslie Kernisan, MD MPH says
Normally the panel should list serum vitamin B12 level, if this test was checked. The confirmatory test is methylmalonic acid.
Good luck!