Vitamin B12 Deficiency and Depression

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Note from Katie: There is a good reason I regularly eat liver (or take capsules) and it isn’t the taste! Kayla Grossman, R.N. (who blogs at Radiant Life Catalog) is sharing her knowledge about an essential vitamin that can affect mental health (and deficiency can lead to depression). Enter Kayla…

It is often referred to as the “energy vitamin”. It is one of the main reasons that moms continue to slip infamous foods like beef liver into family meals.

It is well-known for helping with red blood cell formation, healthy circulation, proper digestion and immune system function.

It has even been shown to support support the body nutritionally and hormonally, clear skin and strong nails.

This nutrient is vitamin B12, and its physical benefits are some of the most-talked about in popular medicine. Yet, we often forget that vitamin B12 is also vital for psychological well-being.

Accumulating scientific research points to vitamin B12 as one of the strongest nutritional factors influencing mental health. Let’s take a minute to talk about why B12 is such an important player in maintaining brain function and promoting positive moods.

Vitamin B12 and The Nervous System

Vitamin B12 has the largest and most complex chemical structure of all the vitamins. It is present in several unique forms, each of which actually has the mineral cobalt hidden within. For this reason, you will also see all of the variations of vitamin B12 called the “cobalamins.” The impressive chemical constitution of cobalamins makes a lot of sense when we think of the wide range of functions these nutrients are expected to play in the body.

Looking at the nervous system alone, vitamin B12 works in a diverse number of areas.

Here are just some of the ways in which vitamin B12 supports the brain and central nervous system:

  • assists in normal nerve growth and development
  • improves communication between nerve cells
  • promotes stable adrenal function
  • provides emotional and mental energy
  • helps with the ability to concentrate
  • bolsters memory function
  • has calming effects to balance moods

How exactly does B12 Work?

It is apparent from the list above that vitamin B12 impacts various dimensions of psychological health, but exactly how it does so is a more complicated question. When we get down to the nitty-gritty science of it, the precise mechanisms used by vitamin B12 to act on the nervous system are not entirely clear. Nonetheless, scientists have a few generalized predictions about the pathways this nutrient uses to get its important work done.

The first is through a process called myelination. All the cells in the nervous system are wrapped in an insulating coating called a myelin sheath. This protective layer, made up of protein and fatty substrates, helps electrical signals to transmit quickly and efficiently between nerve cells.

Normally, vitamin B12 helps to build and maintain these myelin sheaths, keeping conversations between cells going and the nervous system running strong. However, when there is a lack of vitamin B12 in the tissues, as seen with dietary vitamin B12 deficiency and other conditions, the myelin coating on cranial, spinal and peripheral nerves is compromised. Without this shielding, nerve signaling becomes slow and sporadic, leading to a host of neurological symptoms from trouble walking to changes in cognitive function and mood.

B12 also helps with the production of neurotransmitters, those tiny chemical messengers that communicate emotional information throughout the brain and body. It does this in collaboration with a compound called SAMe (or S-Adenosylmethionine in fancy scientific terms), which is naturally found throughout the body as well.

Together, B12 and SAMe (along with other helper vitamins like B6 and folate) regulate the synthesis and breakdown of several important mood-controlling chemicals such as serotonin, melatonin and dopamine. Without enough B12, this elaborate production system falters and neurotransmitters can no longer be released at adequate rates. As levels of neurotransmitters plummet, symptoms of mental health disorders, like depression, can arise.

Vitamin B12 and Depression

As you may have guessed by now, vitamin B12 deficiency is a serious problem when it comes to mental health. Although a lack of B12 can negatively affect the brain in many ways, studies connecting B12 deficiency and depression are particularly compelling.

Observational studies have found that as many as 30% of patients that are hospitalized for depression are deficient in vitamin B12.(1) Many practitioners assume that this number is actually much higher, seeing as B12 testing is not yet a standard procedure when it comes to treating psychiatric patients.

One interesting study followed 115 people diagnosed with major depressive order for six months and monitored their B12 status along the way. Researchers found that higher vitamin B12 levels were correlated with better long-term psychological functioning. Furthermore, they discovered that individuals whose moods improved the most over the course of the study had the highest vitamin B12 levels in the blood, while those whose depression did not change had the lowest levels.(2)

Another group of researchers looked at the B12 levels in almost three hundred elderly people with depressive symptoms, and compared them to those of people who were not depressed. They found that people with B12 deficiency were far more likely to be depressed.(3)

Since that time it has been shown that elderly men and women with vitamin B12 deficiency are 70% more likely to experience depression than those with normal B12 status.(4). This is very important as we know that our ability to absorb B12 decreases as we age, in turn increasing rates of B12 deficiency.

The message behind these studies and statistics is both glaring and essential, and yet time and again screening for B12 deficiency left out of conventional psychiatric treatment. It is high time we start looking at nutritional factors like B12 when it comes to mental health care.

Sources of Vitamin B12

We know that having ample amounts of B12 in the body is an essential piece for maintaining a healthy brain and stable mood. But what does this mean for you?

One of the first steps is to make sure you are getting adequate amounts of B12 in your diet. The Recommended Dietary Allowances (RDA) for vitamin B12 is just 2.4 mcg/day. Many people following a standard, varied diet will reach this amount, however those who avoid or limit proteins for any reason may experience difficulty in getting their RDA. The primary food sources of B12 are animal based and include fish, meat, poultry, eggs, milk and other dairy products.

Specifically, the top 5 foods most concentrated in B12 are:

1. Shellfish (clams, mussels, crab)
2. Organ Meats (like beef liver)
3. Wild-caught Fish (such as salmon, trout, mackerel)
4. Grass-fed Beef
5. Pastured Eggs

If B12 has been depleted for some time, supplementing may be necessary. Generally, vitamin B12 is best assimilated when taken as part of a full spectrum B-Complex that contains all of the other vitamins in the B group (such as B1, thiamine, niacin, riboflavin, folate etc.).

Food-based supplements like grass fed Desiccated Liver (this is the first ever USA sourced grass fed liver) will naturally provide this synergistic combination, as will fermented options like Premier Max-B-ND Live Source Vitamins.

It is also important to note that there are factors aside from diet that influence our B12 levels, and this is where many problems with deficiency arise. For example, certain medications prevent the full absorption of B12 from the gastrointestinal tract. Antacids in particular are known to diminish B12, because hydrochloric acid is necessary for cleaving B12 from foods so that it can be absorbed by the intestines. Health conditions associated with gastric inflammation also create problems with B12 assimilation. Many autoimmune conditions such as thyroiditis fall into this group.

If you are concerned that you may have a B12 deficiency that is impacting your moods and well-being, it is always best to have a conversation with your healthcare provider. Assessing for and treating B12 deficiency can be a very important piece of the recovery process in affected individuals, and a treatment that can be done relatively simply at that.

Additional Resources

Linus Pauling Institute: Vitamin B12

Dietary Supplement Fact Sheet: B12

USDA Food Composition Database

About the author: Kayla Grossman, R.N. is a registered nurse turned researcher and real food advocate who blogs at Radiant Life Catalog (my source for supplements like Vitamin C, Astaxanthin, Probiotics, & Vitamin D and air filters, water filters, and more).

Have you ever struggled with vitamin B12 deficiency? Share below!

Katie Wells Avatar

About Katie Wells

Katie Wells, CTNC, MCHC, Founder of Wellness Mama and Co-founder of Wellnesse, has a background in research, journalism, and nutrition. As a mom of six, she turned to research and took health into her own hands to find answers to her health problems. is the culmination of her thousands of hours of research and all posts are medically reviewed and verified by the Wellness Mama research team. Katie is also the author of the bestselling books The Wellness Mama Cookbook and The Wellness Mama 5-Step Lifestyle Detox.


76 responses to “Vitamin B12 Deficiency and Depression”

  1. Leslie Avatar

    Hi Katie. Thank you for this. Along with other supplements I’ve been supplementing with B12 and feel much better. Since my 22 y/o daughter suffers from depression, I suggested that she take B12 again. Within a couple of weeks of adding to her diet, her face has broken out. She is a young woman that NEVER suffers from breakouts or acne and has a meticulous skin care regiment that works for her. She commented that the same thing happened when she added B12 a couple of years ago.
    Any suggestions?

  2. Ryan Avatar

    Gastrointestinal disturbances might bring about B12deficiency. I have been taking B12 supplements but I want to avoid injections. Has anyone heard of Elligen B12? My doctor and one friend recommended it. Can anyone tell me what they think?

  3. Dawn R. Avatar

    my son is 26 and had is 1st paranoid schizophrenic break down at the age of 21 he went full blown in a very short time we had no idea what was going on with him. 2 years later it happened again. Both times he had to be hospitalized, He also suffers from depression & has very high anxiety and loses sleep very easily. He is just now being approved for disability. When it comes through should I see if they can give him a physical and check his B-12 level? He has been off his medication now for close to a year.

  4. Ashley Avatar

    Any brand recommendations for dessicated liver supplements available on Amazon? Thank you!

  5. Shauna Avatar

    Incredible insight and overview. Depression isn’t a popular thing to talk about, but having proper hormone and vitamin/supplement balance is crucial and surprisingly plays an imperative role in overall health – including your mood and mental well-being. Well don!

    1. Wellness Mama Avatar

      I’d always check with a doctor or midwife before consuming any isolated nutrient while pregnant, but it is found naturally in many foods.

  6. Tracey Avatar

    My Daughter has had constant nausea for the past 5 years. This effects her whole life she was unable to go to High School and now she is working struggles though everyday acting like she is fine when really she is nauseated all day and cannot sleep at night because of it. After a barrage of test we can confirm she is low in B12. She was given B12 and B complex shots which made her worst. We are desperate for an answer and cure.

    1. Jessie Avatar

      Try to get the 23andme gene test done. If your daughter has an MTHFR polymorphism, she may need methylated forms of B vitamins. I hope you’re able to find a solution soon.

    2. Mary Ann Anderson Avatar
      Mary Ann Anderson

      I have a friend and her young daughter had the same symptoms . They tried everything and nothing helped . As a last resort they put her on a gluten-free diet and almost immediately she got better . She is doing great now, it might be worth a shot.

  7. Lora H. Smith Avatar
    Lora H. Smith

    Seventy percent of aged people suffering from Vitamin B12 deficiency are more likely to go through depression. How alarming! I’m 45 years old and a vegetarian and am not even interested in dairy products too. But just two months ago I started feeling depressed and losing my memory. I work in an IT firm, and at that time I was very busy with my official tasks even at home. Therefore, I thought that it was happening for the time being, but everything was getting worse day by day. I even started losing my taste a few weeks later. At last my daughter made me meet my doctor yesterday, and she (doctor) discovered a high level of Vitamin B12 deficiency in me. The doctor advised me to take oral supplements. I’m worried and afraid. Would anyone please let me know whether supplements work for everyone with B12 deficiency or not? I’m surfing net to get effective suggestions to get relieved. Here is another post that says supplements work for almost everyone with Vitamin B12 deficiency.

    1. Marcela Avatar

      Hello Lora! Particularly since you didn’t have much B12 in your diet to begin with, I think starting with an oral supplement is a good idea (and may be all you need). Some studies indicate that a high enough oral dose (several times that of the daily recommended value) even in people who have adsorption issues (and can’t absorb B12 effectively from food or supplements), is as effective as B12 injections (the body is presumably able to absorb enough of the nutrient to meet its requirements). That said, I was taking the highest oral dose available every day when I tested with low blood serum levels, so my personal suspicion is that oral supplements (even sub-lingual doses, which some people tout as more effective) do not work for everyone. So I would say the important thing is to start with the oral B12 but have your doctor carefully monitor your levels and your symptoms. There is a chance you may need to switch (as I have) to life-long injections. Either way, there is not a risk of overdosing as the vitamin is water-soluble and excess just gets flushed out of the system. Good luck, and I hope you start feeling better soon!

  8. Charlotte Avatar

    For those struggling with B12 deficiency, I recently heard about a new alternative to the injections. Has anyone heard of it, it’s called Eligen B12? Apparently it is the first and only true alternative to the intramuscular injection. I recently read that it works as well as the IM injection even if you don’t have intrinsic factor (so even if you don’t have normal gut absorption). It’s a once daily pill that apparently it came out a month or two ago

  9. Brooke Avatar

    This question may have already been asked and I missed it, but I am looking to possibly supplement b12 for my husband and I. We eat meat products (chicken, turkey, egg whites) roughly 3 times a week, so I am thinking we may not be getting the b12 we need. Does anyone know why they only make 500-2000mcg doses if the RDA is 2.4mcg? This really confuses me. I know b vitamins are water soluble and what you don’t absorb your body rids, however I still don’t feel comfortable putting that much more in my body. Anyone care to enlighten me? Thanks!! 🙂

    1. Mike Avatar

      Nutrients are much better utilized with co-factors from whole foods.

  10. Allegra Avatar

    I have pernicious anemia, Hoshimoto’s, and Raynaud’s phenomenon. PA controllable with monthly b12 shots and daily exercise. I will always have tingling and in my hands and feet but it’s really only annoying at bedtime or if I don’t exercise. The doctor discovered my PA after a horrible year of feeling like I was dying on the inside but looking fine on the outside. Mine is autoimmune. I lack the intrinsic factor in my stomach. I have a high risk for stomach cancer. I know this and I really have not been taking care of my stomach. I’ve been in denial but I’m discovering that my body responds to what I eat. I have days that my hands are so swollen that I can’t twist my rings and I gain 5 pounds. I just bought the The Autoimmune Paleo Cookbook and I plan to go to the book signing in Austin. I had the text book symptoms of low B12. It was pretty scary and I have never been more relieved when they called from the doctors office and said I needed to have daily shots of b12 for a week and then every other week. I had a medical reason for feeling sick and crazy. Since my diagnosis I have completed a ironman length race, multiple ultra trail races, multiple marathons and graduated with RN-BSN. My life is not over because of my AI issues. I have set backs and days on the sofa but life is good. My family is pretty amazing and they keep moving!! MOVING is important!! Moving decreases my tingling in extremities.

  11. Stephanie Avatar

    Is this different from taking the FLCO? I would like to take both the supplements together but wonder if the fish liver cod oil would be sufficient.

  12. Bill Avatar

    The article should have mentioned the important fact that possibly as much as a third of the population cannot absorb B-12 from food or supplements due to a lack of intrinsic factor, or, as in the case of older adults, a lack of stomach acid. Intrinsic factor is a protein secreted by the stomach that joins vitamin B-12 in the stomach and escorts it through the small intestine to be absorbed by your bloodstream. Without intrinsic factor, vitamin B-12 can’t be absorbed and leaves your body as waste.

    I had a bout of serious depression and inability to sleep years ago. Despite eating food sources and taking B-12 supplements my B-12 levels measured extremely low. Fortunately, injections restored levels which I have continued to maintain via sublingual B-12 supplements which are inexpensive (they dissolve under the tongue which allows for absorption directly into the blood through the extensive capillary system under the tongue).

  13. Sarah Avatar

    I’m diabetic and take metformin. After much research I learned that metformin causes b12 deficiency in 75 % of patients on this medication. This deficiency often causes b12 deficient neuropathy which is being treated as diabetic nureopathy by doctors. If doctors prescribed b12 with this medicine many patients would be able to avoid the pain of this condition much longer. Un fortunately once this kind of nureopathy starts it is often permanant also because the damage is already done.

  14. Cathy Avatar

    Hi Katie,
    Can you (or anyone else here who would like to chime in!) tell me your thoughts on b12 oils? There is only one company online who sells them and they are applied topically to the skin. Supposedly many people have been able to switch to that from b12 shots who suffer various illnesses – some quite serious. I have been wanting to try them, but have found little to no information on it, except what was provided on their website. The best info I have found so far has been on Andrew Seul’s website,, where he mentions crushing up vitamin b12 tablets and mixing with water and applying to the inside of the nose. Just wondering if anyone else had any thoughts on this….

  15. Charles Grabon Avatar
    Charles Grabon

    A less common related condition may exist in some people who are not assimilating or producing adequate methyl compounds. I recently had a brain-related hormone test (such as dopamine, serotonin) which showed low values for almost all hormones, the only normal level was for a hormone I was already supporting through supplements. I now look for methyl folate and have changed to methycobalamin (B-12) to provide the critical methyl compounds. Some believe there is a gene that is responsible for this condition.

  16. Shelley Avatar

    I was having adranal issues last fall, feeling better now. Nice to know the cause:)

  17. Joan Avatar

    Do you know of a good Vit C powder to put in my smoothie that is not made in China?

  18. linda harris Avatar
    linda harris

    Last fall I bought a 40 lb. box of the best sweet potatoes I have ever had. I washed them, then put them on a large baking sheet covered with foil. Baked till tender, then removed the peeling, mashed them, and measured 1/2 cup portions. I then put them on another baking sheet covered with wax paper sprayed with cooking spray. Froze them and put in freezer bags. I saved a few to dice and roast. My husband said he wouldn’t eat them. Well, I should have bought 2 boxes. My allergist removed white potatoes from my diet, so that just leaves sweet potatoes. We may try to grow some in our little garden.

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