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.
Rose says
I have had 2 bloodwork done 12/18&8/19
Both had low white blood count
Dr suggested see hematologist, could it be low b12 and or iron, my supplements do not have iron in them .
redblood count slightly low too on 8/19 draw
Leslie Kernisan, MD MPH says
If you are low in iron, tests should show a low ferritin level. If you are low in B12, we’d expect a low or low-normal vitamin B12 level and an elevated methylmalonic acid.
I would recommend asking the hematologist to explain what might be causing your low white blood cell count, and how concerned you should be. Good luck!
Bee Craighead says
Dear Dr. Leslie: I like your comments and helping people. I am 94.5 years old and in relatively good health but as you might suspect I do have some problems- one of which is driving me nuts. Had to give up on any athletic acts and am told I am out of balance-to the right. Sometimes I walk like a drunk. This after pretty intensive testing. No explanation or reasons and told to take P.T. and that it was hard to cure and a very lengthy go around. At 94 years it occurs to me that I probably don’t have time left for their P.T.
Do you have any ideas about getting back my balance other than lengthy P.T.? I’m game for just about anything. Bee
Leslie Kernisan, MD MPH says
Hello Bee,
That’s great that you are in relatively good health at age 94.5.
Re your balance, hmm…I find it odd that they didn’t have an explanation, especially if they did extensive testing. How to improve your balance really depends on what they think is causing the issue, so I wonder if it wouldn’t be possible for you to return to your health providers and ask for them to explain what they think is going on. It’s possible that they didn’t give an explanation because they thought you wouldn’t understand. (I hope it’s not that they assumed you were “too old” to understand or be interested!)
Also, is the PT general physical therapy for balance, or did they propose “vestibular rehabilitation”, which is more specifically about addressing balance and vertigo issues?
In general, if you are in good health, then perhaps we shouldn’t say that you “don’t have time left” for PT. It’s always a good idea to work on balance when one is older, and might also eventually help with your specific issue.
Good luck and take care!
paramjisingh says
hello
I am 58 years old and Less Of B12.
Feelings pain in feet bottom in morning.
Frozen shoulder And laziness.
I’m also suffered Blood pressure high.
Prostate Bph. Urine infection.
My muscles are loosing now.
How to avoid medicine And be healthy too.
Feel my eye closed. Why this happens to me.
.Please reply
Leslie Kernisan, MD MPH says
I would recommend a comprehensive consultation with a good health provider. It may take several visits to get to the bottom of things, as your situation sounds complicated.
Pandora MAPLE says
Hi,
My dad has been so poorly he doesn’t want to live anymore (having other chronic pain issues to deal with, being this poorly was the last straw). He was diagnosed with low B12 about 6 months ago. He had a series of B12 shots that made him about 80% better, which was great. He started to go downhill again, so had another B12 shot – again making him a lot better. He had another shot about 2 weeks ago, but it doesn’t seem to have worked this time. Either it’s not a B12 issue or the shots don’t seem to be enough now. Can he ask for shots once a week (he’s been told once every 5 weeks) or would this be bad for him? Maybe he should be using high mg tablets on a daily basis to keep his levels up? Or may there be an underlying issue as to why his body doesn’t want to absorb it?
Thank you for your help!
Leslie Kernisan, MD MPH says
Hm. Before pursuing another series of weekly vitamin B12 shots, I would recommend talking to his doctor and making sure they have tested his vitamin B12 levels (and also methylmalonic acid, if his vitamin B12 level is borderline) to see if he is low.
Poor absorption of vitamin B12 is usually only a potential issue when people take it orally, and should not be an issue when taking injections.
It’s certainly possible that there is another underlying health issue which is causing him to feel poorly, and he may need further evaluation, especially if his vitamin B12 levels are in fact ok. Good luck, I hope he feels better soon.
Patricia says
Dear Dr. Kernisan,
I am vegetarian for two years and my hair has been thinning, nails became dry and brittle and I became fatigued over a span of 5 months. Due to circumstances I wasn’t able to see a doctor right away, so I started supplementing Biotin, Folic acid and 1,000 mcg of B12. Had blood tests last week: Ferritin is 25 ug/L and he didn’t test for B12. My nails are getting better but still fatigued. He recommended iron supplement.
Is 1,000 mcg of B12 considered a high dose for sublingual tablets?
Thank you very much for sharing this info!
Leslie Kernisan, MD MPH says
1000mcg of B12 is a fairly common oral dose used to treat vitamin B12 deficiency.
If you are concerned about possible vitamin B12 deficiency, I would recommend asking your doctor about testing for this specifically. You could be low on iron and also be low on vitamin B12; the only way to assess vitamin B12 status is to test first the serum level of vitamin B12 and then also methylmalonic acid if the vitamin B12 level is low-normal. Even though you have been taking a supplement, since you are still feeling tired and having symptoms, further evaluation would be reasonable. There are also many other conditions that can cause fatigue (e.g. low thyroid), so be sure to ask your health provider about getting checked for other conditions that might cause fatigue. Good luck!
jen says
Hi there
I wonder how best to help my mom who is resisting not trusting any one to check her ears (for justified reasons of being treated abruptly by hca staff and mom’s alone there she’s afraid of some staff) in an assisted living facility Edmonton Alberta. She’s not looking well -hasnt had blood work in a few years won’t let staff touch her – her ears are bothering her she won’t do her hearing aids – she sounds garbled but I can hear her over the phone trying to talk to the hca who is ignoring her.. but it’s as if she’s trying to say it’s painful it’s sore….but the staff don’t listen. I noticed she doubled plugged up a few weeks back. The staff say they can’t do oil in her ear until they look inside – but she won’t let them- is there any thing you can recommend to help get mom’s ears checked her throat etc – also b12 she needed for years I hope they give it to her but I can’t be sure – can you let me know what tests in blood work to ask staff to do -if they can get her blood drawn – she’s really not happy there and I wish I could go get her bring her here to Ontario but there are some other siblings that are being uncaring of her situation at 89 years – it’s so hard. I’m on the phone day night checking her snacks -shes celiac. The good isn’t gluten free and I found out she’s not getting enough food at breakfast and lunch.
If you could let me know what blood tests and other tests they should do – I’d appreciate your help very much.
She’s been through terrible situations and all her kids are Ontario she way out in Edmonton Alberta alone no kids and it’s a huge risk I keep trying to get my youngest brother to realize – he did the unthinkable to her with taking control of her assets etc he shouldn’t have – I couldn’t get help to stop him. He’s left mom far away from him and my sister and me. I wish there was protection for divorced elderly parents to be protected from the kids that took the other side in the divorce. He’s just heartless doesn’t visit her but 1time a year and doesn’t provide for her extra help she needs – it wasn’t her wishes to live in care she was an RN – she didn’t want to have her condo sold her keep sake family things trashed taken to the dump etc – I’m trying my best to be on the phone to check on her and staff but it’s a big worry with her almost crying nono please no you do it…when I try to talk to her on the phone…it’s like it’s hurting her ears.
Any help or recommendations would be so very appreciated – mom doesn’t deserve this kind of care -day after day strangers being rough pushy not compassionate -do TV’s blasting all day affect the hearing -her roommate is hollering at her to answer the phone and says nasty things to mom -ive asked management to get a new roommate but they don’t seem to be listening -she should be with me (for years and years I did nurses aid work and lived with elderly people up to 96 yrs of age) so it was always my hope my goal to be available to attend my own mother when she needed help – I wish I could just go get her but I don’t know who to turn to for help for mom -with being told my youngest brother took my name off her pa pd – he controls everything – sadly.
Thanks for your time and help and I really like your website!
I posted this for mom…heres hope for a miracle…that I can make things better for mom, Reggie C Knowles very soon.
Jen
Waterloo On Canada
N2k4G9
Leslie Kernisan, MD MPH says
Sorry to hear of your mother’s situation. If she is refusing to let anyone touch her, it might indeed be difficult to get bloodwork done. In principle, to check on vitamin B12 status, we would check the blood vitamin B12 level and then also consider ordering a methylmalonic acid level, as I explain in the article.
In terms of advocating regarding her living situation and perhaps her hearing: all of this is very difficult to do if you aren’t able to visit the site and work closely with the facility staff. If you are concerned about her hearing, this should be brought to the attention of her usual doctor or whichever health professional is supervising the medical care of the residents of her facility.
It does sound like your mother’s care is being overseen by a sibling, and that perhaps you disagree with the decisions being made. I’m not sure what your options are in Canada. In the US, generally one would have to look into one’s state laws and consult with an elder law attorney. Sometimes it is possible to petition a court to remove someone as an older person’s guardian, but this is a time-consuming process and also often expensive to pursue. Good luck!
Leslea says
static/file/P29P1.pdf Is the legislation in Alberta for the protection of persons in care. If the OP is concerned about the care, or quality of care, the information is there.
Nicole Didyk, MD says
Thanks for sharing that document. It can be so difficult to try to manage a parent’s care from across the country, so the more information the better! Here’s an article about some of the common issues when helping a parent.
Patricia Abbott says
I am 78 years olg and just had a b12 blood test . It was 193.
Some articles say that the threshold should be 300 in elderly people.
What do you think?
Leslie Kernisan, MD MPH says
193 sounds low. I would certainly recommend discussing this with your usual health providers.
As I explain in the article, a test for methylmalonic acid is recommended as a follow-up. If it’s higher than normal, that would be consistent with vitamin B12 deficiency.
Mary says
Is it true that your body doesn’t absorb B12 supplements unless you have had some type of intestinal surgery?
Leslie Kernisan, MD MPH says
The main pathway for absorbing vitamin B12 requires a working stomach and gastric acid. Hence a surgery that removes the stomach can result in vitamin B12 deficiency. However, studies suggest that if high-dose oral supplementation is used, vitamin B12 deficiency can be corrected even if the stomach has been removed or is not providing acid. This is because there are some secondary ways to absorb vitamin B12 (these pathways aren’t very efficient however, which is why a high dose has to be used).
Oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency: a systematic review of randomized controlled trials.
Oral Vitamin B12 Replacement: An Effective Treatment for Vitamin B12 Deficiency After Total Gastrectomy in Gastric Cancer Patients
Ruthie Fullerton says
I am in early 90’s and have Crohns. Recently am having balance issues . Have
started taking 1000 mg of B12 daily. Any other suggestions ?
Thank you.
Glenna Ivie says
I just read your article on vitamin b12 My question is how long does it take to see improvement in my body your the positive taking 1,000 units 1daily for 10 days I am 82 years old I have ibs,fibromyalgia, acids reflux , i am in wheelchair . Have other physical problems I did have blood work done in June my vitamin B12was low
Nicole Didyk, MD says
A low B12 level can affect red and white blood cell and platelet counts, and these usually improve by about one month after B12 replacement therapy has been started.
The neurologic symptoms associated with B12 deficiency may take longer to improve (3 months to one year), and may not improve completely. Generally, the longer you’ve had symptoms, the longer it may take to improve.
Jannice says
I am 81years, a female, had ear problems as a child, have got progressively worse re clarity of sound, one on one talking over a table is fine, otherwise not good, I have to concentrate when walking due to a balance problem. Recently had a bad attack of vertigo, got medication but still seems to be a problem when turning/etc. to the right.
Seriously considering getting a walking stick. I am interested to note how important Vit.B12 is especially in the elderly, I shall go to the local clinic more regularly for a shot.
I have made a note of balance excercises for the elderly.
Thankyou
Jannice
Leslie Kernisan, MD MPH says
Glad you are learning more about your health. Re vitamin B12, I would recommend being checked for deficiency before pursuing injections or another form of supplementation.
You should also know that the medication usually prescribed for vertigo (meclizine) is quite anticholinergic and so should be used with caution by older adults. You can learn more about the risks of anticholinergic medications here: 7 Common Brain-Toxic Drugs Older Adults Should Use With Caution
Vertigo can sometimes be more safely treated with vestibular rehabilitation, which is a special form of physical therapy. It is more work than taking a medication, but safer.
Good luck!
Ephraim Yangean says
Thank you so much for the education. But I have a concern. An adult was transfused 2016 for the first time in life. From that time to present, she has receive 38 units of blood. What several tests have been done, but low bolld is still the problem. Please help me to help this lady.
Leslie Kernisan, MD MPH says
By low blood, I assume you are referring to a low red blood cell count, which means anemia. (Although it is possible to be low in other types of blood counts, and to sometimes be transfused for this.)
I explain the most common causes of anemia and how doctors evaluate this condition in this article: Anemia in the Older Adult: 10 Common Causes & What to Ask.
I would recommend you review that article and the comments, and then plan to ask the involved doctors more questions about what they think is causing the low blood count. Good luck!
Troy Clark says
I am 52 Years old. My Alive 50+ Ultra Potency Once Daily Multivitamin has 225mcg of B-12 which is like 3750% of your Daily Value. Is that too much? I also Take a Jarrow formulas Methyl B-12 Lemon Flavored Lozenges 1000mcg and split them in 1/2 and let them dissolve on my tongue Daily. My Blood work last year showed everything good so far. My D level is about 1700Iu a day and my Calcium is about 1200 a day. Magnesium 400mg a day. Hopefully those are all good levels. I know B-12 is good for the heart also, Correct? Any feedback will greatly appreciated!
Leslie Kernisan, MD MPH says
The good thing about vitamin B12 is that it doesn’t accumulate in the body and doesn’t cause toxicity. It’s true that the RDA for older adults is 2.4mcg/day, however when we treat deficiency, it’s very common to give people 1000mcg orally per day, and many people go on taking that oral dose indefinitely.
If you want to know if your vitamin B12 dosing is ok, I would recommend asking your health provider to tell you what your level is. It’s probably fine, since it sounds like you take a fair amount of it every day and it is also in many foods. Good luck!
H.M Abdulhussein says
Dear Dr Leslie
I am 68 years old had colon cancer in2008 and stomach cancer in 2010 had stomach removed
My b12 is 165pg/ml
I take b12 injections
I take multivitamin and vitamin d magnesium sometimes
I take fish oil and raw garlic and ginger
Can I take these before b12 injections
Or should I avoid taking them on the day of the injection?
Nicole Didyk, MD says
I’m not aware of any reason to avoid taking other vitamins or supplements before an intramuscular injection of B12, but if you’re not sure, a pharmacist would be a good person to ask.
Richard says
Thanks for the good info. My Neurologist noticed in bloodwork that my B12 was low and prescribed B12 supplement . My RBC is also low. Neurologist also told me have Macrocytic Anemia.
The B12 seems to be helping. I am 80 years old .
Nicole Didyk, MD says
I’m glad you found the article helpful!
Macrocytic anemia is a type of low hemoglobin where the red blood cells are larger than average. Low B12 can be a cause, and so can low folate (another B vitamin), liver disease, alcoholism, low thyroid function, and certain medications.
I’m happy to hear that the B12 supplement is helping!
Jim Ireland says
I had problems mentioned in this article. I changed to a doctor specializing in geriatrics.
He prescribed a B12 supplement. The problems went away in a week.
This shows you how critically important it is to have the right kind of doctor.
The doctor I had had for 10+ years was clueless.
Nicole Didyk, MD says
I’m glad you found a doctor who could help!
May Moffat says
Thank you for the info about B12 i do. Have to get injections which help