Surprising Facts You Need to Know About Vitamin B12

This post provides an introduction to Vitamin B12. Vitamin B12 deficiency is one of the most common deficiencies I see in my Vitamin B12practice. It’s important to discuss Vitamin B12 because it is a nutrient that is essential to many body functions and because many people are deficient and are suffering unnecessarily. (Magnesium is another nutrient that is vital for health but which many people are deficient in. Please read Why You Need More Magnesium – and how to get it for more info on that.) I plan to cover B12 in several blog posts, because I believe deficiencies in Vitamin B12 cause more severe health issues than other nutrient deficiencies, yet 80% of the general public is deficient and is completely unaware of the importance of B12. The symptoms caused by a B12 deficiency can be so severe that they limit one’s ability to function normally, yet replenishing this vitamin is very easily accomplished. Many people associate Vitamin B12 with boosting energy or assisting in weight loss, but it can help improve health in a multitude of different ways. Unfortunately, a severe deficiency may cause damage to brain and nerve cells that is very difficult to reverse.You can read more about Vitamin B12 in Tests for and Sources of Vitamin B12.

B12 deficiencies are a personal passion of mine because I have an autoimmune condition (Pernicious Anemia) that destroys cells in my digestive tract (the parietal cells) which are responsible for absorbing Vitamin B12. I suffered horrible symptoms for many years simply because no one ever ordered the correct tests to identify this issue and because no one ever tested my B12 blood levels. I realized through my own research that I was deficient and began taking a supplement, but it was still several years before I a physician who confirmed my suspicions using specific blood tests. He was the first doc in over 20 years to order the proper tests and to give me a prescription for multiple high-dosage B12 injections per week. I’ll discuss proper testing and ways to replenish low levels later in this post. My primary concern is helping people recognize and eliminate the symptoms a B12 deficiency can cause because I know personally how severe they can be.

What is Vitamin B12 responsible for?

Vitamin B12 is present in, used by and necessary for the proper functioning of every single cell in the human body. Obviously, I can’t cover everything Vitamin B12 is responsible for in a singe blog post, so stay tuned for future info on B12. The most important roles Vitamin B12 plays in the body include:
  • Creation and repair of DNA
  • Creation and maintenance of the myelin sheath that insulates nerves in the body and neurons in the brain
  • Regulation of the production of S-adenosyl-L-methionine (SAM-e), a mood-regulating chemical
  • Support of methylation and detoxification
  • Metabolism of fatty acids and proteins
  • Maintenance of proper function of nerve cells and brain chemistry
  • Energy production
  • Production of red blood cells and hemoglobin
  • Reduction of inflammatory homocysteine – excess homocysteine is associated with coronary disease, Alzheimer’s disease, strokes, diabetes, osteoporosis and more (See Three Blood Tests Almost Everyone Should Request for more info on homocysteine.)

Symptoms of a Vitamin B12 Deficiency

Based on the above list, it is obvious that a B12 deficiency can cause severe health issues. Although all of the B vitamins are essential for true health, a deficiency in Vitamin B12 can affect health in ways that impact daily life more strongly than some of the other B Vitamins. A deficiency in Vitamin B12 may cause any or all of the following symptoms:
  • Anemia
  • Fatigue, sometimes severe
  • Feeling of heaviness in arms, legs and head
  • Muscle weakness
  • Depression and despondency
  • Easy bruising
  • Sleep disturbances and insomnia
  • Hormonal imbalances
  • Elevated liver enzymes
  • Diarrhea, constipation or other digestive woes such as nausea, vomiting, loss of appetite and/or bloating
  • Red, swollen tongue
  • Bleeding gums
  • Pale skin
  • “Brain fog,” problems concentrating, memory loss
  • Shortness of breath on even mild exertion
  • Numbness or tingling in extremities (neuropathy in severe cases)
  • Headaches and migraines
  • Ataxia (lack of balance, may affect gait)
  • Dizziness and lightheadedness
  • White spots on the skin of the forearm (may be misdiagnosed as Vitiligo)
  • Irritability and extreme mood swings
  • Tachycardia, skipped heart beats, irregular heart rhythm
  • Eye twitches and tics
  • Irregular periods, heavy bleeding, infertility
  • Decrease or disappearance of normal reflex responses
  • Some people report pain in their ring finger and palm

Causes of a Vitamin B12 Deficiency

The following are all potential causes of a B12 deficiency:
  • Alcohol consumption
  • Smoking
  • Vegan or vegetarian lifestyle
  • Excessive junk food consumption
  • Digestive diseases and conditions which block absorption (Celiac, Crohn’s, IBS, malabsorption, etc.)
  • Removal or resectioning of the small bowel
  • Use of antacids and prescription drugs used to treat ulcers or GERD (Prevacid, Prilosec, Protonix, Nexium, Zantac, Tagamet, Axid, Alternagel, Maalox, Mylanta, Riopan, Tums, etc.)
  • Gastric bypass surgery
  • The following prescription drugs are known to cause deficiencies in B12: Zoloft, Metformin, Glucophage, Glucovance, K-Lor, K-Lyte, Klotrix, K-Dur, Micro-K, Slow-K, Colchicine (and other prescriptions used to treat gout), and some prescription antibiotics and cholesterol medications.
  • Parasitic infection
  • Liver dysfunction
  • Candida overgrowth
  • Aging – everyone absorbs less B12 as they age. Some experts recommend that anyone over age 50 should take a B12 supplement
  • Pernicious Anemia – an autoimmune condition which destroys the parietal cells in the digestive tract which are responsible for creating a chemical necessary for absorbing Vitamin B12
If any of the above points apply to you, or if you take any of the prescription medications mentioned, chances are you would benefit from using a B12 supplement or from having your B12 levels checked. The blood test to check B12 levels is very common and very inexpensive. Most insurance companies pay for it without question since a B12 deficiency can cause so many symptoms. I recommend having your B12 levels checked at least yearly, or more frequently if a deficiency is found. Alternative methods used to check B12 levels include Electrodermal Screening (EDS) and Kinesiology (Muscle Response Testing). Although I use both of those methods in my practice, the blood test is quick and easy and I recommend asking your doctor to add it the next time you have blood work done. It is especially important for vegans and vegetarians to have their B12 levels checked regularly. The liver can store extra B12 for several years, so it may take time before a deficiency occurs. It is important to check your levels regularly to recognize any change or decrease early. If your B12 levels are consistently low, you may also want to ask your doctor to order a test for Antiparietal Antibodies to check for Pernicious Anemia. (Pernicious Anemia sounds horrible but is very easily combated by taking B12 injections or using sublingual supplements. More about that in my next post.)My next blog post will discuss the different types of B12 supplements that can be used to boost levels in the body. Foods that contain Vitamin B12 include all animal products: all meat (shellfish and calf liver are especially high, but fowl and fish also contain B12), eggs, dairy, etc.
For the record, it is a myth that seaweeds contain B12. Seaweeds contain a chemical that is not B12, but which is close enough in chemical structure that it “fits” into cell receptors for B12, thereby preventing those cells from absorbing true B12. PLEASE DO NOT USE SEAWEED TO RAISE BLOOD LEVELS OF B12.Because plant materials do not contain Vitamin B12 in high enough amounts to improve health, it is IMPERATIVE that vegans supplement with Vitamin B12 on a daily or weekly basis.I’ll discuss ways to boost B12 levels and share my favorite form of B12 in my next post. Until then … live large and pursue wellness!
My passion is helping people improve their health by identifying and correcting systemic imbalances. I have helped thousands of people eliminate their health challenges using a holistic approach. If you are ready to improve your health, please contact me to schedule a consultation. I will help you identify the cause of health challenges and will then work with you to create a plan to reverse them.

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Dr. Pamela Reilly is a Naturopathic Physician dedicated to helping people improve their health and eliminate symptoms using natural, integrative methods. She has over 25 years of experience and has helped men, women and children improve their health using a holistic, client-centered focus. She sees clients in Indianapolis, does house calls, and also conducts consultations via Skype or telephone. Please feel free to contact her or visit her Consultations page for more information. Dr. Pamela speaks nationwide on a wide variety of health topics and welcomes speaking invitations.

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31 Responses to Surprising Facts You Need to Know About Vitamin B12

  1. Rajesh says:

    Hi, I am rajesh from India, 29 male

    I have been recently diagnosed with b12 def which was 183, and for the past 3 weeks i can see my veins are more visible on hands and legs and increasing day by day, and i can see small red veins in my mouth and throat. In my CBP test I have 16.1 hemoglobin, 52 hemotocrit, and 4.9 RBC, and 8800 wbc, I am more worried, these vein symptoms are due to b12 deficiency? Please tell me

  2. Sardine says:

    I recently got diagnosed with a b12 deficiency and I got the injection last week and ever since I’ve been having break through bleeding.. And I’m on the pill. Is this normal?

  3. Karie D says:

    After a B-12 injection I am experiencing a rapid heartbeat. How long does it usually last?

  4. Sahar says:

    Hi..I know this is an old post but… I share so many symptoms & no one ever told me it could be Vit B12 deficiency. Thank you so much for such an enlightening article. Many thanks again.

  5. Jess says:

    Thank you for this information ! I too have “self-discovered” my B12 deficiency -I am an RN of 18 years and have struggled with severe Anemia for most of my life. In the last couple of years (i am almost 40) I have struggled with increasingly heavy periods- hot flashes -difficulty with circulation (worsening of Raynaud’s syndrome) decrease of mental focus -lethargy -easy bruising and the list goes on . Over the last 3 weeks I have started self administering B12 injections . My hot flashes are almost completely gone! I have more energy, increased mental clarity and this week I had my first period that is light and manageable and only lasted a couple of days vs a heavy flow for 5 to 7 days- the results are incredible and truly amazing I have less headaches and have a better sense of well-being! I’m a Believer in B12!! I have started giving high dose B12 oral supplements to both of my boys who have ADHD and I’m starting to see a difference!!

  6. Tawnya says:

    This was extremely helpful! I have a lot of the symptoms of a deficiency so I may schedule a test to have my levels checked. I do take b12 along with iron supplements during my menstrual cycle because it’s heavy and prolonged. I never thought it was the b12 doing most of the work! Since starting this regime my cycles have started arriving on time and becoming less heavy. I suppose I should start taking the b12 everyday now instead of just on my period!

  7. Chris says:

    Not sure if this helps or if you are interested but I recently heard about a new oral prescription alternative to the injections called Eligen B12. I recently read that it works even if you don’t have intrinsic factor (so even if you don’t have normal gut absorption). Apparently it came out a month or two ago. Has anyone heard of it or tried it??

  8. rai says:

    Hello, I know this is kind of an old thread but I’m looking for answers right now and really not finding any! I live in Thailand and have IBS so I lose a lot of water and minerals from a colon that pushes things out too fast. About two months ago, I started feeling “strange” I would have bouts of extreme fatigue (I’d get home from work and just lie down and not want to get up) but these would come and go. Then, I started feeling muscle cramping and weakness in my legs. I’ve always been a strong athletic woman so these symptoms were depressing for me. Well, I started taking a multivitamin because I wasn’t before that and things seemed to even out a little and I wasn’t so tired anymore. Just two weeks ago I had my period and it was heavier than usual and a little longer than usual… but it passed. However, right after that I had a bad bout of diarrhea. I had it for like 4 days straight and it was a lot. I figured it was from the IBS and tried drinking plenty of water and electrolyte powders (sodium-dextrose-potassium).
    During that time and following after, I started having blood spotting like a period. It would come and go come and go but it was always fresh blood (bright red) and would seem to come in giant drops or free flows at randoms moments and then stop… and then start up again at another random date. I’m still experiencing this as well as some other not fun symptoms including bruising easily. I bump anything and I bruise bad. On and off feeling of soreness on my tongue that also comes and goes at random. Tingling and numbness in my fingers, hands and feet. This is a new symptom that’s really been bothering me for about 3-4 days now. It’s pretty constant too. Also a general overall feeling of sadness, irritability and confusion. I forget things waaay too easily. I’m confused as to whether all this is from a hormonal cause or a vitamin deficiency of some sort. I had a blood test to check thyroid levels less than a year ago and then they were fine. Normally my periods are pretty predictable and I’ve never had the sore tongue and numbness until recently. Could I not be getting enough B12 because of my IBS problem and the PPI blockers my doctor put me on? Or is this a strictly hormonal issue? Should I try a supplement? Should I go get tested? For what? If you can help, I’d greatly appreciate it. Thank you in advance.

  9. […] sodium than regular (pork) bacon does. For more information on the nutrients mentioned here, read Surprising Facts You Need to Know About Vitamin B12, Why You Need More Magnesium, and Facts About Iron-Deficiency Anemia. […]

  10. jayh says:

    I have recently had white spots appear all over my body. My dermatologist thought a had vitiligo. She ruled that out because it was only a partial pigment loss. I thought maybe I was anemic or something like that because I am always tired and read that white spots could be related to that. I had test done for insurance at work and my iron serum was actually elevated. Does this sound like a b-12 deficiency?

    • GWWR says:

      Hi. It sounds as if you have an iron overload condition which needs to be investigated. The iron overload can cause all of the symptoms you mentioned. Please discuss this with your regular physician. Eliminating the iron overload will diminish your symptoms. I wish you well!

  11. Julie Martin says:

    Hi Sandra, thanks for all this very helpful info. I will have the doc order the other tests you mentioned. I started in 2007 having tingling in hands/feet, pain in ear when yawning, mouth ulcers, hives, eyelid twitches (usually when sneezing, etc), bleeding gums, brain fog, cramps in feet. I was diagnosed in 2002 with Candida Glabrata which they cannot treat really. I am now on a anti-candida diet and natural supplements trying to get rid of it. My B12 level in 2008 was 261. I’m being retrested soon. I never knew that candida could cause vitamin deficiency but it doesn’t surprise me. Can you explain how that happens? Thanks again, Julie

    • GWWR says:

      Hi, Julie. (My name is Pamela.) Candida causes nutritional deficiency because it causes inflammation in the digestive tract and because it actually bores holes in the colon lining. Both of these factors impeded absorption and may lead to nutritional deficiency.

  12. […] depletes the body of B Vitamins, Magnesium, Potassium and other essential nutrients, so taking a multi-vitamin before you drink and […]

  13. Kristine Treweek says:

    I have a 17 year old boy who has been suffering with tics since he was six years old . These tics are really strong and at times been full body ie head-eyes mouth, sniffing, shoulder, hands ,legs. They are bought on by illness, stress, growth and change. At times he can have an episode that lasts months, they will settle to mild tics and then flare again. I have often wonder if he was low on something but I have always been refused when I have asked for tests to investigate. He is extremely active and perspires uncontrollablly. Am I heading in a safe direction in adding Vit B12 to his diet?



    • GWWR says:

      Hi, Kristine. I’m so sorry to hear about your son’s struggles. I encourage you to find a doctor who will do the correct testing to check for nutritional deficiencies. Nutritional deficiencies can and will affect the central nervous system, so it is worth looking into. Search for a naturopathic doctor, integrative MD or a functional medicine doctor in your region. I apologize I cannot say whether or not adding B12 would be beneficial. You would need to check with your son’s doctor about that and discuss it with him or her. I will say that it is a very common deficiency and that the B vitamins are water soluble, meaning the body easily eliminates any excesses via the urinary tract.

  14. Becky says:

    I have been reading your site with interest.
    I have recently seen a neurologist due to problems I have been experiencing with numbness and tingling especially on the left side of my body.The sensation usually eminates fromthe left eye area.
    An MRI followed by a CT scan has revealed a benign bone exostosis which is not pressing on any sensory nerve so that is good news.
    However my symptoms are getting worse.I have numbness/burning/electric shock like pains over my face,head,hands and feet.It is really unpleasant.I also have headaches,nausea,supressed appetite,memory problems, vagueness, imbalance etc
    I am a coeliac.I have had problems with anaemia over the years. I was recently told my vit D levels were low but a recent blood test revealed they weren’t too bad.My vit B12 levels were about 300( max in range 800. I live inMiddle East.My doctor said bloods were fine but so many of B12deficiency symptoms seem to apply to me.Whilst in the UK over the summer my kineasiologist said I was low in fish oils and B12.He told me I needed 20 drops of B12 (normal daily dose 1drop)
    I have basically been told that I am fine and nothing more can be done.I am trying to be really positive but I am finding it difficult to deal with the symptoms.
    Do you think I might benefit from vitamin b12 injections?
    Any advice would be welcome.
    Thank you

    • GWWR says:

      Hi, Becky. So sorry to hear about your challenges. Most doctors I know consider a B12 level of 300 to be far too low. If I were you, I would discuss it with my doctor and start supplementing. I take B12 injections because I have an autoimmune condition that makes it impossible for me to absorb it, but I also use a sublingual methylcobalamin form of B12. Your issue appears to be more structural in nature than nutritional, but additional B12 is worth considering. I wish you well with your journey!

  15. Becky says:

    I have been reading your site with interest.
    I have recently seen a neurologist due to problems I have been experiencing with numbness and tingling especially on the left side of my body.The sensation usually eminates fromthe left eye area.
    An MRI followed by a CT scan has revealed a benign bone exostosis which is not pressing on any sensory nerve so that is good news.
    However my symptoms are getting worse.I have numbness/burning/electric shock like pains over my face,head,hands and feet.It is really unpleasant.I also have headaches,nausea,supressed appetite,memory problems, vagueness, imbalance etc
    I am a coeliac.I have had problems with anaemia over the years. I was recently told my vit D levels were low but a recent blood test revealed they weren’t too bad.My vit B12 levels were about 300( max in range 800. I live inMiddle East.My doctor said bloods were fine but so many of B12deficiency symptoms seem to apply to me.Whilst in the UK over the summer my kineasio

  16. sandra jones says:

    In the last month I began taking Raspberry Ketone (Tropical Oasis brand) and have been taking Super B complex for over a year ( Spring Valley brand). I was diagnosed this week with Deficency of B vitamins because of the Red, swollen, cracking tongue. My Dr. changed me to All Bee with C a B complex supplement. However I did not mention the raspberry ketone to him and he will be out of town for about a week. can you help me. Thanks Sandra Jones

    • GWWR says:

      Hi, Sandra. That is a question for your doctor. I am not familiar with Raspberry Ketones being known to deplete the body of B Vitamins; however, any physical stress will sap the body’s supply of B Vitamins very quickly. The effect of the raspberry ketones could indirectly affect your levels of B Vitamins. If I were you, I would stop taking the raspberry ketones until I could discuss them with my doctor. Being deficient in B Vitamins can interfere with weight loss, so you may not need them once your deficiency is corrected. I wish you well!

  17. […] Having it run every time your doctor checks your A1C and/or insulin levels works well. Please see my post, Surprising Facts You Need to Know About Vitamin B12for more […]

  18. […] Tests For and Sources of Vitamin B12 This post is a follow-up to my last post, Surprising Facts You Need to Know About B12. Please refer to it if you want basic information about what B12 is responsible for in the body, […]

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