How Much Vitamin B12 Should you Take for Your Thyroid?

How Much Vitamin B12 Should you Take for Your Thyroid?

The Relationship Between Your Thyroid and Vitamin B12 Status

Would it surprise you to know that a great many thyroid patients are vitamin B12 deficient?

Or that the symptoms of vitamin B12 deficiency can closely mimic hypothyroidism?

The truth is that any thyroid patient who suffers from LOW thyroid (including those with hypothyroidismHashimoto’s, those who are post-RAI, and post thyroidectomy) is at increased risk for Vitamin B12 deficiency. 

This deficiency is so common that I recommend using B12 for almost all hypothyroid patients regardless of what your labs show. 

In fact, studies show that as many as 40% of ALL thyroid patients have this deficiency (1). 

But how much should you take? If you don’t take enough then it won’t do you any good. 

What type of B12 formulation should you use? If you aren’t using the right kind of activated B12 then it may not help you. 

How should you go about getting the B12 into your body? Sublingually, orally, or via injections?

Today we are going to answer all of these questions and more. 

Let’s jump in: 


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B12 Deficiency is More Common Than You Think

Why is vitamin B12 deficiency so common among thyroid patients?

It’s actually quite simple. 

Your thyroid helps to regulate important aspects of intestinal function including intestinal motility (how frequently your bowels are moving) and how much acid your stomach produces (via their impact on specific cells in the stomach). 

If you suffer from low thyroid (again, from any of the causes listed above) then 2 important things will occur:

#1. Your stomach will not produce sufficient stomach acid. 

And #2. Intestinal motility will slow down (2)

If your stomach is not producing enough stomach acid then you will have a problem not only with the digestion of your food but also with the absorption of certain nutrients, chiefly vitamin B12. 

It turns out that your stomach actually NEEDS to produce acid for these things to occur. 

And conditions that lead to low stomach acid also lead to a myriad of nutrient deficiencies, including B12 deficiency. 

But that’s not all. 

Low stomach acid also contributes to changes in your gut bacteria (3) (microflora). 

how much vitamin b12 should you take for your thyroid

Changes in these levels can alter the absorption of foods AND nutrients as well. 

One common intestinal problem that thyroid patients face is small intestinal bacterial overgrowth (known as SIBO). 

Those with SIBO have problems with absorption of nutrients, and foods, and often have high levels of inflammation in their gut. 

The bottom line?

Low thyroid function sets your body up for vitamin B12 deficiency. 

Vitamin B12 Dosing in Thyroid Patients: How Much is Enough?

If you’ve made it here then it should be obvious that using B12 in any low thyroid state is probably a great idea. 

If the 40% deficiency figure didn’t help then surely the physiologic information should have. 

If you are following me so far then you are probably wondering how much B12 you should be using.

And I wish it was as easy as saying “You should use this much” and calling it a day. 

Unfortunately, the devil is in the details. 

While I can’t say exactly how much you should be using I can give you some pertinent information that will help guide you. 

Important point #1. You can’t really overdo it when taking vitamin B12

In other words, there’s really no such thing as overdosing on vitamin B12 (4). 

This may come as a shock to you but vitamin B12 is INCREDIBLY safe. 

I can always tell when a doctor has no idea what they are doing when they recommend that a patient stop taking vitamin B12 because their blood level is “high”. 

We will talk more about why that makes no sense at all below but you should be aware here that serum B12 testing is very inaccurate and shouldn’t be used to guide dosing. 

Furthermore, vitamin B12 is a water-soluble vitamin which means that it is eliminated through your urine (pee). 

As long as your kidneys are working then your body will have no problem getting rid of any excess B12 that you may take by mouth. 

So don’t be afraid to take moderate to high doses of vitamin B12. 

Important point #2. The form of B12 that you take will impact your dose. 

Depending on which type of B12 that you use (again, we will talk more about this in a minute) it will affect how much you need to take. 

For instance:

If you take your B12 via the sublingual route (under your tongue) or via a shot (injection) you will probably need less than if you take your B12 in a capsule. 

This isn’t a hard and fast rule, though, as you will see below. 

Important point #3. Consider these dosing guidelines. 

Still not sure how much B12 you should be taking? 

Let this act as a guideline for you: 

  • Oral capsules – 400-1,000 mcg per day (if using an isolated B12 supplement)
  • Sublingual B12 – 1,000-5,000 mcg per day. 
  • Vitamin B12 injections – 5,000mcg each week. 

This is only a guide!

You may find that you need more or less, depending on several factors including whether or not you are severely B12 deficient or just want a daily maintenance dose. 

The Best Form of Vitamin B12 for Hypothyroid Patients

Vitamin B12 can come in many different forms and they are not all created equal. 

If you have no idea what I mean by B12 formulation, let me explain:

The actual B12 component of Vitamin B12 is often bound to another carrier in a supplement form. 

This carrier helps the B12 get into your body faster (or slower) depending on which carrier it is bound to. 

As you might suspect, some of these carriers are much better than others which means that they will be more easily absorbed and utilized by your body. 


What is the best way to get vitamin b12 shots if you have a thyroid problem? Find out why I think b12 shots are the best. #thyroidsupp #b12 #b12shot #thyroidtreatment #hashimotos

♬ original sound – Dr. Westin Childs

If you are a thyroid patient, the last thing you want to do is to use a low-quality formulation of B12 because it will just make it that much harder for it to get into your body (it’s already difficult enough as is). 

When using B12 you want to look for pre-methylated or pre-activated formulations of B12. 

These formulations are already ACTIVE and do not require any changes once they are absorbed in order to be utilized by the body. 

These pre-methylated and pre-activated formulations of B12 are also SAFE to use if you have the MTHFR genetic mutation. 

Statistically speaking, as many as 40% of people have this issue whether they are aware or not. 

So which forms do you want to use?

These would be considered ‘approved’ B12 forms for thyroid patients:

What types of B12 should you avoid? Well, anything that isn’t listed above but do keep a watchful eye out for this type of B12:

  • Cyanocobalamin

Cyanocobalamin requires activation by the body and is not as readily available as the other forms listed above. 

In addition, when cyanocobalamin is metabolized it will form cyanide which must be eliminated by the body. 

The cyanide produced from the metabolism of cyanocobalamin is not lethal but it will still require effort and energy by the body to get rid of it. 

Why would you take a form of B12 that creates a potential metabolite that can cause problems when other versions do not?

Cyanocobalamin is the cheapest form of B12 so you will frequently find it in cheap supplements where manufacturers are trying to cut costs. 

If you are already taking a B12 supplement then go grab your bottle and see what kind of B12 you are taking. 

Believe it or not, what type of formulation of B12 you take can make a big difference so do not neglect this step! 

The more activated and bioavailable forms of vitamin B12 tend to be more expensive but they are worth the extra money, especially for thyroid patients. 

Oral B12 vs Sublingual B12 vs B12 Injections

What about the route that you take B12?

In my experience, by far the best way to take B12 for thyroid patients is with injections. 

Injections bypass the intestinal tract, where a lot of absorption issues occur, and make their way directly into your muscular tissue where they can then be circulated through your body. 

I lost count of the number of thyroid patients that I’ve treated who were taking sublingual or oral B12 only to respond amazingly well to B12 injections. 

The main issue with B12 shots or B12 injections is that they can be somewhat difficult to obtain. 

In order to get B12 shots, you will need to get a prescription from your doctor. 

Also, they tend to be a little bit more on the pricey side. 

But the cost is definitely worth it. 

which form of b12 is best for thyroid patients

I know that there are studies that show that sublingual B12 is as good as B12 injections (7) but my own experience suggests that this is NOT the case. 

If you can’t get B12 shots or injections then you can go with either sublingual B12 or oral B12 as both can still work. 

Sublingual is probably slightly better than oral B12 capsules but I don’t think the difference is that huge. 

Again, the studies suggest that both sublingual and B12 injections are superior to oral B12 capsules but I personally find B12 shots to be far and away the best. 

Signs of B12 Deficiency in Thyroid Patients

How do you know if you are B12 deficient?

The best way is to look at your symptoms. 

We will talk about B12 testing in just a second but for now, let’s talk about what type of symptoms you may experience if your B12 levels are low. 

I mentioned previously that the symptoms of B12 deficiency can mimic hypothyroid symptoms which can make the diagnosis hard to spot. 

This is one of the many reasons I often recommend that thyroid patients just supplement with B12 in almost every case. 

But if you want to look for the symptoms then see this list below…

Signs of B12 deficiency include: 

  • Fatigue or low-energy
  • Hair loss
  • Weight gain
  • Brain fog
  • Depression
  • Numbness/tingling
  • Tongue changes
  • Constipation
  • Heart palpitations
  • Anemia

Because many of these symptoms can be masked by a low thyroid many people are tempted to check their serum B12 levels…

Testing for Vitamin B12 Deficiency: Do you Really Need to?

Some people get into the mindset that they must check their labs before using any supplement.

There’s only one problem with this approach:

Lab testing for nutrients is not always accurate. 

In fact, lab testing for many nutrients can give you misleading information, especially if you don’t know what you are looking at. 

Vitamin B12 testing fits firmly into this category. 

The most commonly ordered test for assessing B12 deficiency is known as a serum B12 level. 

Unfortunately, this is also the least accurate way to measure vitamin B12 status in your body. 

And despite the fact that this is well established in the literature, you wouldn’t know it based on how many doctors continue to order serum B12 levels. 

To combat the inaccuracy of the serum B12 test, doctors will sometimes use a test called methylmalonic acid, or MMA for short instead. 

This test is more accurate but still misses a large portion of B12 deficiency AND is quite expensive to boot. 

It’s actually cheaper to simply purchase a B12 supplement and take it for 2-3 months instead of paying for the price of the MMA test (which is what I recommend). 

Testing MMA may make sense in some situations, however, so keep that in mind. 

Beyond the serum B12 test and the MMA, there are also other tests that you can order to get a sense of your vitamin B12 status. 

These next tests are not specific to diagnosing vitamin B12 deficiency but they do give you a general idea as to whether or not your body is able to utilize B12. 

These tests include:

  • MCV (mean corpuscular volume)
  • Homocysteine

MCV is part of the standard CBC (complete blood count) and it tends to be HIGH when you are B12 deficient. 

Likewise, homocysteine is also HIGH if you are B12 deficient. 

If you check these labs and see that your MCV is greater than 92 and that your homocysteine is greater than 10.0 there is a HIGH chance that your B12 levels are NOT optimized. 

If either or both of these values are over the recommended range then it would be a good idea to supplement with both folate as well as vitamin B12. 

Once you’ve done this for 2-3 months you can then recheck your homocysteine and MCV levels to check for improvement. 

Any improvement can be thought of as an indirect improvement in your vitamin B12 status. 

I prefer to use these tests over the standard serum B12 test and MMA testing because they are easy to get, cheap, and also provide additional information on your overall health. 

Final Thoughts

As a thyroid patient, you should be aware that there is a very high chance that you are suffering from vitamin B12 deficiency whether you realize it or not.

Because the incidence of B12 deficiency is so high among thyroid patients I often recommend that every thyroid patient takes a B12 supplement (or at least takes B12 in one or more of their supplements) in some form. 

You will find that many of my thyroid-specific supplements contain B vitamins (including B12). 

Even just using a B12 supplement for 2-3 months is enough to build back up your stores of B12 to ensure that your thyroid has what it needs. 

You will probably NOT need to take a dedicated B12 supplement for a long period of time, but it is a good idea to ensure that you have enough to meet cellular demands. 

Lastly, vitamin B12 supplements are incredibly safe even in large doses. 

Keep in mind, though, that impaired kidney function may impact how much vitamin B12 you will want to take. 

But because most people do not have kidney issues, this usually isn’t something you need to worry about (if you have kidney problems you will know it!). 

Now I want to hear from you:

Do you know if you are B12 deficient?

What type of thyroid disease do you have?

Have you tried taking Vitamin B12 in the past? Did it work for you? 

Have you tried B12 injections/shots? 

Leave your questions or comments below! 

Scientific References








how much vitamin b12 do hypothyroid patients need?

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About Dr. Westin Childs

Hey! I'm Westin Childs D.O. (former Osteopathic Physician). I don't practice medicine anymore and instead specialize in helping people like YOU who have thyroid problems, hormone imbalances, and weight loss resistance. I love to write and share what I've learned over the years. I also happen to formulate the best supplements on the market (well, at least in my opinion!) and I'm proud to say that over 80,000+ people have used them over the last 7 years. You can read more about my own personal health journey and why I am so passionate about what I do.

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49 thoughts on “How Much Vitamin B12 Should you Take for Your Thyroid?”

  1. Hi Dr. Childs
    I have taken both sublingual and injectable B12.
    I have hashimoto’s thyroiditis.
    My ND prescribed 2000mcgs injections every 3 days.
    ** my question.. she prescribed subq injections.
    Should I be doing IM injection???

  2. Hypothyroidism here. I ordered my own tests and B12 was under 400 and I can naturally assume I was low in folate because after taking a supplement for three months I retested and B12 went up to 750 and folate 17. My iron serum was 133 and ferritin 47. I’ve been trying to eat oats and lentils since I don’t get any fortified foods and have a low appetite and obviously low stomach acid from my low T3 levels. I looked back at some labs several years ago and my B12 was over 600. Working on the very slow process of bringing up T3 levels….very very slow lol

  3. Hi,
    My B12 serum levels were just tested. The level was over 1200–way over range for the second time in 10 months. I take a B12 supplement in my daily multivitamin–100mcg per day. ( I had an MCV in the normal range–91.1.) With a B12 level this high is it possible that I am not absorbing the B12 I’m taking? I did have B12 levels in the 600 range, but that was about 8-10 years ago. I have not been tested for the MTHR genetic mutation…
    Thank you.

  4. Thank you Dr Childs. Would you recommend a HLC digestive enzyme in general for those with hypo and if so , what dose and what product would you recommend?

    How does one know if their thyroid no longer functions? My medical inutitive says it is at 50% and doc says pretty much non functional . I believe in healing so….. im not giving up.
    Can I slowly work on healing it and getting off armour if I use a little kelp powder daily and bring tSH down along with all the other things to work on? ( liver,adrenals,digestion, stress reduction etc?) I have weight loss, not gain and hair loss- mainly due stress as eat correctly but not enough or absorb poorly. What amount of seaweed iodine would be safe to take with armour with tsh at 16 and t4 slightly low and 4, 15 mg tabs of armour daily? I want to heal this and beleive I can by healing all. Thank you so much for your time and input.

    • Hi Barbara,

      Digestive enzymes certainly have their place in treating Hashimoto’s, Graves’, and hypothyroidism. The best way to identify if your thyroid is working is to either go off of your thyroid medication completely to see where your thyroid lab tests fall or to get an ultrasound and check for thyroid gland atrophy.

      • Dr. Childs, I would be so interested in doing this. How long would you recommend not taking meds before seeing if they fall? How low would they need to fall to show your thyroid isn’t working at all? Will this work if you have Hashi? Also, I’ve never ever had an ultrasound. No goiter, no swelling. Should I have one? (BTW I take Armour Thyroid 45mg – well, one 30 and one 15. Anything over that gives me severe anxiety even if my tsh is high, etc. The highest the TSH ever went was 15 but normally it seems to stay around 4 to 7 no matter what. It’s been so frustrating and I never feel well so I do wonder if I can go off of them completely. BTW – I take B12 injections at home for years now due to taking PPIs years ago. Thank you for helping all of us!

  5. Thank you Dr. Childs for this article! Have you ever heard of B12 causing fatigue?? I know it sounds funny because B12 is supposed to give you energy! And in most people it seems it does. I received a B12 shot a couple of years ago, and on the way home I almost had to pull my car over, as I was about to fall asleep at the wheel! Although there were other ingredients in there, I have found that 1,000mcg of sublingual methylcobalamin causes me to become very tired.

    Without supplementing with B12 and during a fasting blood draw recently:
    Serum B12 = 922
    MCV = 95 (over 92, so high)
    Homocysteine = 7.8 (less than 9, so normal? Some folks say high is over 7.2.)

    When supplementing with B12 (at night…lol) more than 1 year earlier, and during a fasting draw:
    Serum B12 = >2,000
    MCV = 92 (slightly high)
    Homocysteine = 8.6 (even higher!)

    Should I be supplementing? I’m so confused as to what’s going on with me and B12.

  6. Hi,
    I m hypothyroid patient with T3= 117, T4=10.2 & TSH=2.84 taking 50 mcg daily. Already taken mecobalamin 500 mcg for 1 month. Recently tested B12 =304. Low vitamin D =23. My MCV is 105.6 and Want to know when and for how many months B12 oral will be taken and after what gap it needs again to start and vitamin D3 how much needs to be taken for weeks?

  7. Hi Dr. Childs,

    Thank you for all you do! You have helped me greatly over the years. You are my go to source for all things Thyroid/Auto Immune Disorders.

    One thing I would like to add about B12 deficiency that wasn’t mentioned is to let folks know that there is a condition called “Pernicious Anemia” whereby the stomach cannot absorb B-12 so it must be injected. One can get tested for Parietal Cell antibodies and Intrinsic Factor Antibodies to distinguish between the two and in this case B-12 injections are for life and not temporary boosts to get the body back to speed.

    Hope this helps!

    • Hi Emily,

      I should have mentioned pernicious anemia since it is frequently seen with Hashimoto’s 🙂 Thanks for the reminder!

    • Hi Carla,

      I’m not sure how liposomal B12 would compare to various forms of B12. It’s almost certianly inferior to b12 shots and, at best, potentially equal to sublingual formulations. Absorption through the skin is generally not very easy because the skin acts as a barrier to PREVENT the absorption of most things.

  8. I am post thyroidectomy for 32 years. I am 54 years old and went thru menopause. Started when I was 48. Haven’t had menstrual cycle in 4 years. I have all symptoms of hypothyroidism. Since I was 48. I remember having a B12 shot once because I was dragging and it was a miracle. I never thought I would need it all the time. Is there anything different I should be focusing on since I do not have a thyroid? I had thyroid papilloma that metastasized in my lymph nodes. Also had right neck dissection. Been on synthroid 100mcg since thyroidectomy. Haven’t had one issue until menopause. My t3 t4 TSH is all messed up. I’m getting a full lab next week. Going that will tell me what is going on. I hope it is just B12 deficiency.

  9. Thank you for this article. I just told my mom to get a B12 shot. She unfortunately has had a terrible Dr. that never listens to her. She is 83 and has lost a great deal of weight, lost most of her hair and is a walking skeleton. She used to have a lot of energy but now is very tired. She has been on thyroid medication most of her life. But I believe the different Drs. in her life has messed up her thyroid. I think the synthetic has devastated her health. She used to be on a natural a long time ago. Your article has given me an answer to the many symptoms she has. I believe now she hasn’t been absorbing her nutrients for some time probably because of B12 deficency. I pray it’s not to late to help her.

    • Hi Laurie,

      Most conventional doctors aren’t familiar with B12 so you will probably need to look elsewhere to get the right dose/type. It’s just not something they typically teach in medical school/residency.

  10. Hi Dr Child,
    Thank you for another great article.

    I was always told Vit B12 should balance with folate as tend to use the same pathways. Therefore, if we risk taking our VitB12 levels high, should we not be supplementing folate alongside?

    • Hi Gill,

      I’ve never seen issues clinically when using high dose B12 without folate but if you feel the need to use folate with B12 you can certainly do that. Most of the supplements I recommend now have both folate and B12 built into them.

  11. Hi there,
    Very short, simple question…? Can I take B12?with my thyroid medication or should I wait the 1-4 hour window.

    • Hi Janelle,

      It’s best to wait at least 30-60 minutes unless you are using B12 shots. You can probably make an exception with sublingual sources of B12 but I still would wait the 30-60 minutes to be on the safe side.

  12. hi dr childs,i have a func med doc,im 70 m and do well with my thyroid.
    in fact i take t150 and seaweed kelp caps daily,my numbers GREAT.
    I took a chance on getting a special price on trying a drop of nacsent
    iodine,a half hour,,,, so horrilbe my bp went to 220 over115,,,i felt so
    lifgtheaded for 30 min,could barley stand up. how could that product
    hit me so radical lasted 4 hours.please comment thanks jack

  13. I don’t know if I am B12 deficient but I have most of the symptoms. I do take B12 but see no effect. The P5P I feel a difference but minor.

    I have been treated off and on for hypothyroid since I was 11yo. I basically treat myself these days with supplements and ask my doctor for changes to medications based on what I research. I feel best when my T3 is on the higher side of normal but it always puts my TSH too high.

    I did take an injection of various supplements years ago when doing a diet program. It made me feel better but not sure what was in that injection. Looking back now it could have been a scam or experiment.

    What do you think of those skin patches of B12? They are sold by several companies on amazon. I tried one company but did not feel any difference.

  14. I had complete thyroidectomy surgery in 2018. I take synthroid every day, but I am still losing my hair and can’t lose the weight. I have never heard about B12 deficiency being a possible contributor to my symptoms. I will give it a try.

  15. Learn SO much from your articles. THANK YOU! I just found a functional doctor that listens to me and am so grateful. I hadn’t been taking B complex for awhile & was experiencing most of those symptoms. I recently restarted & feel some better. My TSH 3.02, T4 Thyroxine 5.10 (low), T3 uptake 24.0 (low), T7 FTI 1.20 (low), T4 free direct 0.770 (low), Total T3 102.0, Free T3 2.90, TSI 0.0 and Reverse T3 9.40 (low). Finally had antibodies checked and TPO was 16.0. You recently responded that I have Hashimotos Thyroiditis. I believe my antibodies aren’t real high as for 5 years I’ve been cutting out gluten the best I can and know that helped tremendously. My labs showed stomach acid issues so am waiting for results of an urine analysis. I’m on 45mg (1-30mg & 1-15mg) NPT sublingually at bedtime. Besides that I take your thyroid adrenal reset supplement (helps greatly!), Vit C 500mg, D-3 5000 IU and now the active B complex plus enzymes with meals. Is my NPT the right dose beings many of the labs were low? Any suggestions? Appreciate your expertise!

  16. I have most of the problems listed in this comments section. My doctor is treating me with Tirosint ONLY, should I mention a small dose of T3 Cytomel to combine with this. I will begin taking B12, my doctor told me the same just today, that I may be deficient in B12. I have been diagnosed with hypothyroidism since May 2020, and I have not lost a pound despite changing how I eat, I have gained 3 lbs since I started Tirosint in April 2021. I feel a lot better, it’s expensive, but I want to feel good, so it is worth it. Thank you for being here, so happy I found your blog!

  17. Hi Dr Childs. My husband just got gastric sleeve surgery done (the one where 80% of the stomach is removed for weight loss) about a wk and a half ago for. The surgern said husband has to take B12 for the rest of his life, and recommends 500 mcg chewable or sublingual B12 daily or 1000 mcg weekly. Your Power B complex only has 400 mcg in capsule form. Do you know if your Power B is good for this type of surgery? If so, how does he get to 500 mcg daily with your product(s) in sublingual form? And do you know if he can skip taking B12 every couple of months as mentioned in this article or the surgern is right about him having to take it continuously for rest of his life?

    • Hi Diana,

      He can still definitely take power B complex but what I would recommend is that he has an individual source of B12 that is completely different from power B complex, preferably B12 injections as those are ideal for someone in his situation. The power B complex will serve to replace other B vitamins since they are more easily absorbed compared to B12 but he should be getting B12 from either the sublingual source or from injections (preferably weekly injections). The sublingual form is a bit easier to get compared to the injections but not quite as good. If he wants to get sublingual B12 then using a chewable or liquid is preferable.

      He probably can skip a few doses here and there but he will probably feel much better taking it regularly.

  18. Hello,
    Please help me understand the situation as I am lost here. I was diagnosed with Graves’ disease in 2016 and had afib recently because of it. I was told yesterday that I have Hoshimoto disease. How is it possible to be hypo and hyper at the same time. I was given FERROUS GLUCONATE for a month and was asked to get over the counter vitamin d and take methimazole and that is it basically. I am not sure I am getting the best care but I am limited with my insurance.

    • Hi Imra,

      It’s not possible to be both hyperthyroid and hypothyroid at the same time but you can have both disease states. When you have Graves’ or Hashimoto’s, one condition dominates and determines your symptoms. In your case, it sounds like that condition is hyperthyroidism otherwise you wouldn’t be on methimazole. What gets even more confusing, though, is that methimazole often induces a hypothyroid state while treating your hyperthyroidism.

  19. I am wondering if treating B12 deficiency can cause hypothyroidism to normalize or create hyperthyroidism. I’ve been hypothyroid for 25 yrs. and now my doc says I’m hyperthyroidism and to stop taking my thyroid hormone.

  20. Hi,
    Thank you for the insightful article. I have a hx of hypothyroidism and IDA. Genetic mutation +\+ MTRR and +\- MTHFR. I have always had high serum b12 even before I knew what vitamins were and was a vegetarian my whole life. I also had elevated folate levels around the same time. Over 5 years ago I developed anemia symptoms and started treatment for IDA. Anyway a few months ago I developed tingling in my hands and feet that gradually progressed to glossitis. I became more forgetful, off balance, hair loss, hyperpigmentation etc. I’d tried everything and nothing helped. For a while I thought folate was helping but realized it wasn’t. As a last ditch effort I started getting b12 injections: hydroxocobalamin and gradually noticed improvement in the glossitis and tingling… to the point of resolution. Because I still have IDA I still have some of the above symptoms. Meanwhile my MMA, homocysteine, and serum b12 has always been normal. Granted I haven’t had the first 2 checked for over 5 years but during this time my serum b12 was still high. any thoughts?

  21. I’m so happy to have found your post. I endured all this with my mum thinking that she has dementia because she is 93 years old and in perfect health except for her thyroid chronic problem, but now that I’ve found the cause of all her deterioration through doing extensive research on the web, and also fell on your amazing article. My mum is much better. I wish Medical and Nutrition Schools teach all this information and that hospitals and Nursing care centers do the correct screening and treatment for their patients and not jump directly into conclusions and start giving the wrong medications to treat the symptoms not the root cause of the problem.

  22. I suffered from subclinical hypothyroidism for a number of years. I am female of 53 years old.
    I have put on a few pounds . Do you think taking B12 will help me with regards to my weight.
    As I am borderline with Hasimoto’s, no treatment has been given.
    Do you also think that a low dose of levothyroxin might help with my weight problem.

    • Hi Louise,

      It’s unlikely that B12 or levothyroxine will have any meaningful impact on your weight by themselves but if they were combined with a healthy whole-food diet, regular exercise, stress control, and quality sleep then they would likely help your situation.

      There are also plenty of treatments that you can use right now to help improve your thyroid naturally without the use of medications:

  23. Hi Dr. Childs,

    I am looking for a pharmacy near me that provides the Methyl B-12 injections and have not found one. I have the MTHFR defect. I live in Newport, NH. Any Suggestions?

    Gratefully, Susan

    • Hi Susan,

      I don’t know of any pharmacies in that area but you can search for local compounding pharmacies and you should be able to find a few.


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