How to Detect & Treat Vitamin B12 Deficiency in Older Adults

Vitamin B12Everyone 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  a body’s  ability to make “intrinsic factor.” 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, 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 and Treated

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 him.

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.

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.

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 typical initial treatment for a significant vitamin B12 deficiency involves intramuscular shots  – 1000 micrograms of the vitamin. This bypasses any absorption problems in the stomach or intestine.

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.

Are There Other Benefits To Taking Vitamin B12 Supplements?

Since we know vitamin B12 is necessary for 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.

Print FriendlyComments
  1. 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 blood 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 in 2008 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.

  2. Jannice says

    I am 81 years, 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 exercises for the elderly.

    • 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!

  3. Mary says

    Is it true that your body doesn’t absorb B12 supplements unless you have had some type of intestinal surgery?

  4. Patricia Abbott says

    I am 78 years old 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.

  5. 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 -hasn't 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 -she's 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.

    Waterloo On Canada

    • 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!

  6. 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!

  7. Pandora MAPLE says


    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.

  8. paramjisingh says

    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.

  9. 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!

  10. 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 .
    red-blood 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!

  11. 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 discharge from 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 with out quadcore cane and it 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!

  12. 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.

  13. 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 disequilibrium sensation. They may walk more slowly and tentatively, and reach out for a support.

  14. 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 a lot 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 pursue 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 fingerpick 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.

  15. 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.

  16. 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.

      • 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.

      • 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.

  17. 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.

  18. 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 methyl cobalamin and cyanocobalamin, but as long as it is taken consistently, either one will do, and most people find oral supplementation preferable to a shot.

  19. 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.

  20. 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.

  21. Anonymous says

    Dear Dr. Kernisan, Date Composed: 7/11/2020

    Thanks for your fascinating article on B12 deficiency. I’m also worried by it, as I’m 83 and I have had long-standing, slow developing symptoms in all your categories of Anemia, Neuropathy, and Cognitive Impairment.

    I’m reluctant to ask my regular Kaiser physician for a blood level test, as going into the hospital for lab work means potential exposure to the corvid-19 virus, which I’ve worked hard to avoid. My wife, a retired nurse, suggested a note to you would the best way to start seeing if B12 might help.

    Anemia. For 2 or more years now I suddenly became much more tired when taking a walk. Up one flight of stairs or half a block, and I want to stop and catch my breath. The tired, breathless feeling is like what used to happen after several flights and many blocks. I used a pulse oximeter, it showed 97-98% oxygen in my blood in spite of my feeling tired, but the tiredness is real.

    Neuropathy. Tingling on tips of toes starting a couple of years ago, now over most of my feet. Charley horses in legs used to be rare, once or twice a year, now once a week or so. Neurologist diagnosed me with length dependent axonal symmetrical polyneuropathy, nothing to do about it. Not feeling as stable on my feet when walking, occasional mild, transient dizziness.

    Starting in my early 20s, “tension” headaches. (I put quotes around “tension” as no doctor has ever done what seems obvious, put a hand on my temple to see if I feel tense…) Lots of diagnostic work, no cause found. I have records, slow creeping up of headache intensity/duration over decades, now chronic, lasting most of a day. Years ago aspirin or Tylenol, then they became no longer effective, started small doses of codeine w Tylenol. For the last several years regularly six 60 mg tablets per day on average, little variation. Not a cure, but keeps headache pain levels down some to where I can still write scientific journal papers in my fields, but much lessened productivity. No side effect that I know of from the codeine except temporary constipation for a few hours after taking, generally not a problem. At least 7-8 alternative Rx drug treatments tried, no reduction in headaches, unacceptable side effects of unsteadiness in walking and obvious forgetfulness.

    Cognitive Impairment. I am still perceived as smart and normal from the outside, but from the inside my immediate sensory memory is shortened and less comprehensive, and I don’t feel as intelligent. I can retrieve what I need from long-term memory, but it takes longer.

    I’m still active in my specialty research fields and would like to have more energy and fewer headaches: I have a number of interesting observations and useful (I hope) ideas to share that my younger colleagues might find of value.

    So B12?

    I’ll end with a story that may amuse you. My wife and I heard you lecture and were very impressed. Obviously we should have a gerontologist like you look over our medical treatments. I asked my primary care doctor to refer me to one of the Kaiser gerontologists. She looked at me for a few seconds, then told me “I’m sorry, there’s no way I can certify you as decrepit.” How nice! 😉

    Thanks for your writings and this chance to ask a question.

    Anonymous (for professional reasons)

    • Nicole Didyk, MD says

      Thanks for sharing your story and that anecdote!

      It’s true that a deficiency in vitamin B12 can cause symptoms that are similar to what you describe, as can a great many other disorders, or combination of disorders. When I see a patient with a slowly developing constellation of issues, I take the usual Geriatrics approach and take a look at everything from sleep and activity levels to medication lists, and all that’s in between.

      It can be tempting to want to try a vitamin B12 supplement, and not likely to do any harm, but I would advise anyone to review things with a pharmacist or doctor before spending money on a potentially unnecessary tablet.

  22. CT Berg says

    Your timing on this was perfect and thanks so much! I have horrible drenching night sweats daily at age 70 and female, an accelerating problem for the last year. I was just about to press for a B12 test when c19 precautions derailed everyday care and kept home. But I would love to get this aggravation solved.

    My grandmother allegedly had pernicious anemia 50 years ago. So when I did a PubMed scan and found Canadian reports of a Swedish study where b12 injections solved the elderly night sweat problem quite well, I thought this might be my issue too, especially since I have no other bothersome symptoms.

    Have you heard of B12 helping severe chronic night sweats? The few physicians I have been able to ask can’t even guess and my PCP might like hearing this is a plausible theory.

    • Nicole Didyk, MD says

      I have never used B12 injections to treat unexplained night sweats and I confess to not being able to find the Canadian study that you quote (despite being Canadian myself), but I did see one in the Scottish Medical Journal that was a case study of 3 patients who had improvement in night sweats when the B12 was replenished. The theory was that the B12 deficiency caused a problem with the autonomic nervous system, which was caused by a B12 deficiency.

      The occurrence of night sweats can signify a more serious issue in some cases, so I would only suggest trying a B12 supplement after other potential causes of the sweating have been ruled out.

      • CT Berg says

        Thanks so much for your time. I think we were looking at the same root data — and yes it was conducted abroad, but also reported in a Canadian journal that I found via Google scholar. I am fairy confident the other possible causes will be ruled out in my case, but yes, will review with my PCP. Thanks again!

        • CT Berg says

          FYI, here is the cite that I found:

          Vitamin B12 deficiency causing night sweats

          HU Rehman
          First Published October 3, 2014 Case Report Find in PubMed

          Vitamin B12 deficiency is common. It is known to cause a wide spectrum of neurological syndromes, including autonomic dysfunction. Three cases are discussed here in which drenching night sweats were thought to be caused by vitamin B12 deficiency. All three responded dramatically to vitamin B12 therapy.

        • Nicole Didyk, MD says

          Yes, it’s the same article! Just remember that case studies are informative but don’t have the same level of scientific rigor as other types of research (like randomized clinical trials). Nonetheless, for some medical questions it’s the best evidence we have. Let us know how your trial works out!

        • Suzanne Dixon says

          Hi, I was just wondering if B12 inj5ections helped with your night sweats, my Mum has all other classic low b12 and used to have injections pre covid but all of a sudden has started having night sweats. I too saw the case studies but her GP will not entertain it.

          • Nicole Didyk, MD says

            It can be frustrating to feel like you’re not being heard by a medical professional. Oral B12 supplementation is a reasonable thing to try if injections aren’t feasible. I usually advise about 1 mg of B12 daily.

            And again, don’t overlook other causes of night sweats, like infection or a medication side effect.

  23. Mary Kay says

    Thank you for your article on Vitamin B12 deficiency. My Dad (turned 90 last week) has been suffering from chronic fatigue, walking problems/falls, and cognitive impairment for about 5 years. Early on he received a B12 shot and his blood levels of B12 have been well above 900 pcg/ml for several years now, but his symptoms continue. Despite the above normal level, one neurologist prescribed 1000 mg B12 supplement daily which he has never taken. Is it possible for an older person to have normal levels of B12 in the blood but a problem with the cells being able to use it? Would taking a B12 supplement help?

    • Nicole Didyk, MD says

      Good question.
      The lab test for Vitamin B12 is fairly good, with a “sensitivity” of over 90% (will detect the deficiency accurately 90% of the time). If a person has an intrinsic factor deficiency though (a condition also known as “pernicious anemia”), the test might give a normal result when a person is actually B12 deficient. This can happen with some other conditions as well, like some types of cancer, liver disease or kidney disease. So the test may be normal when a person is actually deficient.

      When we see a patient with a suspected B12 deficiency, and they aren’t responding to B12 replacement therapy, there are some other lab tests that we can do to look more closely at cell metabolism. We can measure two other substances called Methyl-malonic acid (MMA) and homocysteine. Depending on what these tests who, this can help to determine if there’s a true B12 deficiency, or something else is going on.

      You also ask if he could have normal B12 levels but not be using the B12 appropriately, and there are some conditions that can cause this. They are usually related to other factors that are needed for cell metabolism, such as a deficiency of another factor (like folate), so if that’s the case, the problem isn’t really a lack of B12, it’s something else and taking B12 wouldn’t correct it.

      To avoid unnecessary lab tests, and because B12 is cheap and safe, we normally go ahead and give a B12 supplement when levels are low, or when we suspect that a B12 deficiency is present. In an older adult with multiple difficulties, a Geriatrician would probably look at more than just a B12 level to try to tease out what’s causing the symptoms and what to do to help.

  24. David C says

    I have taken 2000mg of Metformin daily for at least 12 years. My RBC count is borderline low (4.1). I experience daily fatigue despite walking two miles daily. I am 74. I suspect my age and Metformin use could cause B12 deficiency. Would you advise being tested for B12 and folate levels?

    • Nicole Didyk, MD says

      Metformin, commonly used to treat Diabetes, can reduce the absorption of Vitamin B12 in up to 30% of those who take it, and the longer a person takes Metformin, the higher the risk of lower B12 levels. For most individuals, adequate dietary intake of B vitamins, or the use of a multivitamin or Calcium supplement is enough to keep B12 deficiency at bay, but if a person has other risk factors for B12 deficiency, then it’s probably a good idea to get it checked.

      In North America, it’s unusual to have a folate deficiency because of the addition of folate to many processed foods, but we often check it as well if a person is showing signs of B12 deficiency (like problems with the peripheral nerves or anemia).

      Fatigue can be complex to sort out, and can have almost innumerable causes, so when I’m seeing a person with fatigue I usually need to go over their entire health history, physical examination, mediation list and more, before ordering tests. But checking B12 is often part of the complete workup.

    • Nicole Didyk, MD says

      Sorry to hear about your difficulties. Symptoms like the ones you describe could be related to a low Vitamin B12 level, but they are also what we doctors call “non-specific” which means that they could be part of many different disorders.

      When I see a patient with complaints of fatigue, pain, and balance problems, I start by asking questions to find out more about how long the symptoms have been there, what makes them worse, whether they are associated with any other features, and so on. I would also do a complete physical examination and probably run a few lab tests.

      Another very important piece of the puzzle is to look at the medications that an older person is taking. Unfortunately, medication side effects can include fatigue and balance issues in some cases.

  25. sharlene delauter says

    I am 73 yo female who has been a vegetarian for 50+ years. I recently (within the last year) started taking Vitamin B12 supplements of 1000 mcg/day because I learned of poor absorption after 65 and that vegetarians are at higher risk for stroke because of low homocysteine levels. My B12 level checked out at 598 pg/ml in August. I’m assuming I should continue doing what I am doing. But is there any danger of having levels get too high at this dose?

  26. Sriram Krishnan says

    Dear Dr.Leslie Kernisan
    Your articles both on B12 and Vitamin D and the FAQ’s has been of a great directional help on these required micronutrients for a common person on the street. I am a 54 year old male from India and a vegetarian since birth. I have been taking supplement for the both B12 and D3 for the last 2 years when the level of b12 was 112 and d3 was15. After the initial loading doses when these levels were above the required normal, my great confusion was how to maintain these levels. Your articles have cleared my doubts and I now take the maintenance doses with lot of confidence. Many thanks for helping and supporting us through these expertly articles . Looking forward to your guidance in future and also wish u pots of good luck and God bless u. Thanks from India.

    • Nicole Didyk, MD says

      Hi Sriram and thanks for taking the time to share your story! I’m so glad that you found a routine that works for your health needs. Your kind feedback about the articles is greatly appreciated. Keep reading!

  27. bhevin singh says

    Hi Nicole,

    In the recent test of my mom who is 71, we found her B12 level is 220….she also has cholesterol and low iron…when we met the doctor he only gave medicine to control cholesterol, but didn’t mention supplements for b12 and iron…..we mentioned about b12, but he says, its normal, no need to give….but I feel its low, and its better to treat early rather than wait. My question can we give b12 supplements to patients who is having cholesterol issues…and what should be the dose…..between 500 -1000 mcg ? waiting for your reply.

    • Nicole Didyk, MD says

      Hi Bhevin. As far as I know, there’s no reason to avoid B12 supplementation if a person has high cholesterol or is being treated for high cholesterol.

      When I recommend a B12 supplement, I usually suggest 1000 mcg, but I can’t give medical advice over the internet, so I would check with your pharmacist to know what does is right for your mom.

  28. Swapnil Dusange says

    Hi, this is Swapnil from India…i m 25 yrs old male..on 22nd april i felt like a i scared a lot after then. My heart was beating very fast (98-115/mnt)…for 15 days, So i went to local MD doc..he gave me tablet of anxiety and depression (typtomer 10 and inderal 40)..when i took that medicine at head was like full of worse thoughts , felt like i was alone…then i stopped that medicine, wait for 4 those 4 days every day after waking i have feeling of sleepiness like my eyes are closed. So on 8th may i went to MD neurologist. He did blood urine and vitamin b12 test…B12 level was 225. He gave me 5 rejunex forte injections and told me that take it on every 3rd day…till now i took 2 shots…heart beats are normal. That scared feeling is low but till there..will those remaining 3 doses gives me full recovery?? Please help .

    • Nicole Didyk, MD says

      My practice is in Geriatrics so I don’t work with older adults, and I can’t give medical advice over the internet, especially to one so far away in India. It sounds like you’re really concerned about your health and I’m glad to hear that you have a local MD to work with. Good luck.

  29. Teresa Bloomberg says

    Hello there. My mom is 81yo and has had progressive decline in her cognition in past couple of years. She is in good health, no longer takes BP medicine, just aspirin and levothyroxine. Her cholesterol runs around 200.

    Her Vitamin B12 level was critically low in 2020. (30years ago she was on B12 shots but they were stopped for some reason)

    She saw my neurologist on my recommendation back in November 2020 where he detected an elevated MCV in her historical labs. This concerned him as that MCV was drawn early 2020, and that her PCP overlooked this.

    She’s been getting regular B12 injections since December 2020. Past 5 mo are subcutaneous injections that my dad is administering to her. Her May B12 level was 198. I find this distressing. She was re-evaluated by my neurologist in March 2021 where we noted she is stable, diagnosed with MCI.

    I’m a career RN so I’m knowledgeable. I work FT and live an hour away from my parents. I’m very concerned that she is not getting the medical attention she needs from her PCP.

    I can really use your feedback as it is causing me stress. My Mom always had a sharp memory. Seeing these issues with short term memory worries me.

    Thank you so so much! I very much look forward to hearing from you.

    Teresa from New Jersey, USA

    • Nicole Didyk, MD says

      Hi Teresa and thanks for taking the time to share your comments. I hope you’re staying well as a nurse during COVID, it’s been a difficult time.

      It’s always hard to care for a parent from a distance, and I can understand your frustration about the gaps in health care for older adults. It sounds like you’re concerned about whether a missed B12 deficiency could have contributed to your mom’s mild cognitive impairment (MCI).

      For most older adults, oral B12 replacement is sufficient, unless there’s a lack of intrinsic factor and B12 can’t be absorbed by the gut. But 198 is a lower B12 level than I like to see in older adults (I usually consider over 300 to be the target for B12 levels).

      The relationship between Vitamin B12 and cognition is complicated. When we look at large databases of older adults with Vitamin B12 levels, like in this review of 18 studies of B12 levels, it seems that low homocysteine levels (which is seen in individuals with low B vitamin levels) correlate with higher rates of dementia. But replenishing B12 in those with low levels doesn’t appear to help with cognitive performance, or to prevent progression to dementia.

      It sounds like you’re such a good support and advocate for your parents and you’d probably enjoy Dr K’s new book: When Your Aging Parent Starts Needing Help. It has useful advice about how to maximize communication with your parents’ healthcare providers which can greatly reduce stress. The book can also help you decide how to “pick your battles” and decide where to focus your energy.

      When it comes to MCI, my advice is to exercise, eat well, and stay socially connected (hard to do during COVID). I made a video about that which you can watch here.

      Thanks again for taking the time to share your story and I hope you keep coming back to the site.

  30. 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.

  31. 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.

    • 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:

      Vitamin B12 is usually low cost and has few side effects, if any, so it’s reasonable to add.

  32. 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:
      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.

  33. Kathleen Todora says

    In recent months my RBC, Hemoglobin, and Hematocrit numbers are dropping. from normal readings over a year to Low. now…..Hemoglobin now 10.3 Hematocrit 30.6 and RBC 3.18…no iron deficiency no occult blood, and diagnosed 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 Methylmalonic 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.

  34. 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.

  35. 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.