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.
colleen says
My 92 year old aunt has been taking generic Protonix , 40 mg, since fall 2017. Would this medication make it difficult for her to absorb B12 tablets? If so, how to counteract this?
Nicole Didyk, MD says
Pantoprazole (Protonix) is an antacid from a class of medications called proton pump inhibitors, or PPI’s for short. Those who take PPI’s are more likely to have a B12 deficiency, but the good news is that the PPI’s do not interfere with the effectiveness of B12 supplements. If a person is concerned that their PPI could be reducing the absorption of dietary B12, they could take an oral B12 supplement, of about 1mg (1000 micrograms) per day.
Fred says
I am a 61-year old male and my primary care doctor has diagnosed me as anemic (hemoglobin averaging about 12.5). We have run appropriate GI tests for bleeding (upper endoscopy, colonoscopy, and stool) which are all negative for blood. My vitamin B12 is showing fine (830). She put me on 400mcg of folate. We are planning on doing a folate test during my next bloodwork. My concern is that the folate supplementation may mask any true B12 deficiency. Is this a valid concern? And if so, how do we best get an accurate B12 reading?
Nicole Didyk, MD says
Folate is another “B” vitamin and deficiency of folate can cause anemia, just like B12 deficiency. If a person has a B12 deficiency and folate deficiency, and only replenishes the folate, then, yes, it could correct some of the blood tests, and a doctor could miss the signs of the B12 deficiency.
That’s why we typically order B12 levels and folate levels at the same time. If a doctor knows that the B12 level is adequate, then the folate supplement can be taken safely. Another option, if a B12 level isn’t available, is to prescribe the B12 supplementation at the same time as supplementing the folate.
So, a person can still get an accurate B12 level tested even while taking folate.
Alison Buchanan says
Thank you for posting this article. I had Vitamin B12 deficiency diagnosed because of my symptoms after a blood test two years ago now. After being told I would need injections, I did some research and found out that Methycobalamin is the most absorbable B12, and found a good supplement. As you have already said, it took around two weeks before I felt well, but my levels have stayed sufficient ever since. I have regular blood tests to confirm that the level is good. I also read that it’s easier to maintain a steady level of Vit. B12 by taking supplements, because with injections the level can drop off causing the patient to feel unwell again before the next injection. Is this correct information? Thank you for your column – It’s excellent!
Nicole Didyk, MD says
I’m glad you enjoyed the article! I haven’t looked at the difference between methylcobalamin and cyanocobalamin, but as long as it is taken consistently, either one will do, and most people find oral supplementation preferable to a shot.
Tony says
Another great article, Leslie! Thanks!
A personal experience: Age 82, easily fatigued and short of breath, mild balance problems. I noted my hemoglobin was 10, mildly macrocyclic. My family doc did not mention this, but I got suspicious of B 12 deficiency. My daily vitamin/mineral pill contains 25 micrograms of B 12.
Despite the axiom that “ a doctor who treats himself has a fool for a patient,” I began taking 500 micrograms of B 12 orally each day. 4 months later my hemoglobin is 13, my exercise tolerance and balance improved.
Judith Edwards says
I’m 79 years old and was diagnosed with Pernicious Anemia several years ago after being diagnosed with Atrophic Gastritis which caused the Pernicious Anemia. I’ve been getting once monthly B12 Shots at my doctor’s office ever since. It was never an option to take high doses of oral B12; B12 could not be absorbed by someone with my auto-immune stomach condition other than by injection, bypassing the stomach. I have no problem with needles, but it would be easier to take a supplement at home. I already take other supplements. Thank you.
Nicole Didyk, MD says
It’s true that most of the time, monthly shots are used when there is a true lack of intrinsic factor (such as if part of the small bowel has been surgically removed, or an autoimmune disorder), but some recent studies suggest that oral replacement therapy can be equally effective for most people with absorption issues. That could be great news for someone who wants to have more flexibility.
Judith Edwards says
Thank you so much for your answer, Dr. Didyk. I decided to order a B12 5000 mcg supplement that was paid for by my medical benefits. I’m an active, high energy person and never noticed a deficiency until my doctor wouldn’t let me come in for my shot for 2 1/2 months due to Covid. After the shot I felt a huge burst of energy. I’ll be curious to see if the sublingual B12 gives me that kind of burst.
Nicole Didyk, MD says
I hope it helps!
Judith Edwards says
Thanks, again.
Linda Levine says
I am almost 79 and have a somewhat complicated health history. I have had 3 bowel resections as I have Crohn’s disease and 3 times was obstructed and was told parts of the bowel that was removed are where absorption of some vitamins and minerals take place so I should take b12 shots monthly. Orally taking them would not be satisfactory as they would not be absorbed sufficiently. Those who have had surgery must take this into consideration when taking B-12 orally and still not feel 100%. I am still tired but also have hypothyroidism. I have a new GP and never had a physical as she doesn’t see patients in the office yet due to COVID. It is a scary time for senior health care. I feel we are forgotten and just falling through the cracks
Nicole Didyk, MD says
I can relate to your feeling of slipping through the cracks and I’m glad you’re staying on top of your medical issues.
It’s true that if a person has certain conditions that get in the way of B12 absorption, injections may be needed.
I hope you make a good connection with your new GP and can get in for a face to face appointment soon. Most physicians in Ontario are getting back to in person care and although there’s a backlog, your wait shouldn’t be too long.
Jill Godmilow says
I’m 76, reasonably healthy. I read your article twice but never discovered a recommendation for a daily supplement for someone without B-12 deficiency.
What would that be? And if one wanted to try the B-12 shot, how much? Once a week, once a day.
Confused, Jil
Nicole Didyk, MD says
When I prescribe B12 replacement, I usually suggest 1 mg, or 1000 micrograns per day. Injections are intramuscular and are usually given on a monthly basis. Depending on the severity of the deficiency and the services offered by a particular office, there could be some variation in the doses and frequencies of administration.
Elizabeth says
Your article is very timely for me, I am 72 and in pretty good health.
2 weeks ago I started taking a daily B12 supplement, cited as a help to some “cold sores” that lasted too long and herpes balms didn’t seem to help. They are gone now, but I can’t say that the B12 actually did that.
However I couldn’t find any warnings so I decided to continue with it.
You article answered alot of questions that I didn’t even know to ask and because of the current situation I only had phone checkup with my doctor for my meds review. I asked him about B12 but since there was nothing for him to see and no other obvious problems we didn’t persue it.
Your article specifically mentions balance which reminded me that lately I have felt a bit off. I get migraines which can make me feel that way, but I only take a pill when I start to feel pain and I didn’t worry about it.
I also take ferrous sulfate for a previous anemia condition which put me back to normal on that score, but I had a drive through fingerprick a few days ago at my doctor’s to check my a1c (which is still very good, I am pleased to say) and I noticed that my blood didn’t look as dark as it has been.
I am grateful for your information and now have a clearer picture to discuss with my doctor. I will continue with my B12 without concern of any toxicity.
Thank you.
Nicole Didyk, MD says
I’m so glad you found the article helpful. The balance issues caused by serious, prolonged Vitamin B12 deficiency are usually related to a loss of “proprioception” which is essentially knowing where your feet are when walking! But balance is affected by so many variables, that’s why many people with balance issues end up seeing a Geriatrician.
Karla says
Thank you for the informative article. My question is about my 65 year old husband. He has had GERD symptoms and took antacids and acid blockers for years. At this point in his life he has mild anemia. He walks like his ankles are stiff, but does not have numbness in his feet. When you mentioned that vitamin B12 deficiency can cause problems with walking I wondered in what way? I am going to have him start taking B12 but just wondered about your thoughts.
Nicole Didyk, MD says
As Dr. Kernisan mentions in her article, B12 deficiency can cause “neuropathy” which is essentially nerve damage, usually starting with the feet. This makes it more difficult to tell where one’s feet are in space, and that makes walking more challenging. It doesn’t typically cause numbness. In severe cases, the B12 deficiency can affect the spinal cord as well, further affecting walking.
People with a neuropathy usually have a wider base of support when they walk, and may They may describe feeling “dizzy”, but it’s more of a dysequilibrium sensation. They may walk more slowly and tentatively, and reach out for a support.
Jan says
My mom is 80 years old and has had to get 3 blood transfusions and tonight is on her 4th. They are saying she has a B12 vitamin deficiency. Shouldn’t the DRs be giving her B12 shots. She is becoming very sick and weak and they keep masking the problem with blood transfusions. Can you help me understand what I should be doing to try to help her more. Any advise you can give will be helpful. Last blood count was 21.6.7
Nicole Didyk, MD says
I’m sorry to that your Mom is having these difficulties. I’m not sure how to interpret that number you gave for her latest blood count, a hemoglobin level of 21 does not really make sense, and that would also be extraordinarily low if it were her B12 level. In any case, it is unusual, in my experience, for someone to need repeated blood transfusions for the anemia from B12 deficiency. I wonder if there is another cause of her symptoms and her need for transfusions. In terms of shots, we often start with an intramuscular B12 injection before putting someone on oral B12 replacement, especially if the B12 level are very low. Here’s a podcast that might be helpful.
Ann says
Due to a slip and fall I broke my left femur (hip) which resulted in a compound fracture. I had to have immediate surgery where I had a rod and two screws inserted. The surgeon informed me prior to surgery that it was likely I might need a transfusion due to blood loss resulting from teams. My hemoglobin got down really low and I was given a blood transfusion. I had a CBC done every day for 4 days until dischargefrom from hospital. When discharged from hospital hemoglobin was 7.6. Haven’t had it repeated since discharged. Last visit to my physician he seemed to think I looked quite well and said he didn’t think any lab work was necessary. I feel good, am walking every day wI thout quadcore cane andit amI not tired. Still have some discomfort at times when I overdue. Vital signs are within normal range. Should I be taking any supplements? Surgery was June 10, 2019.
Leslie Kernisan, MD MPH says
Sorry to hear of your fall. It does sound like you’ve been recovering and feeling well, which is reassuring. Your hemoglobin at discharge was quite low, so even though you are feeling ok, I think it’s not unreasonable to ask your provider if it can be checked on, just so you know what your baseline is now.
Supplements to treat low hemoglobin are only indicated if there is a documented nutrient deficiency (e.g. low iron, B12, etc). Good luck!