If you've been feeling anxious, low or foggy, it makes sense to wonder whether a vitamin could be part of the picture. B12 is one of the few nutrients with a real connection to the brain. But the link is narrower than many headlines suggest.
Written by Vita Globe Editorial Team | Reviewed against NIH guidance, systematic reviews and peer-reviewed research
Can low B12 cause anxiety or depression?
B12 deficiency can cause psychiatric and neurological symptoms, including mood changes, sometimes even before anemia appears[1][2]. Some studies have found links between low B12 and depression[3]. But a meta-analysis of randomized trials found that B12 supplements didn't improve depressive symptoms in people without advanced neurological disorders[4]. Research specifically on anxiety is limited.
Caveat: Anxiety and depression have many causes. If you're struggling, please talk to a healthcare provider. B12 is not a substitute for mental health care.
Sources: Lindenbaum et al., NEJM 1988 · NIH ODS · Markun et al., 2021 · Verified 2026-09-27
IN THIS ARTICLE
How is B12 connected to the brain?
B12 is needed for the development and function of the central nervous system, including myelin, the protective coating around nerves[3]. It also works with folate in pathways the brain uses to make important molecules, and low B12 causes homocysteine to build up[5]. That's why severe or long-lasting deficiency can affect memory, thinking and mood as well as the nerves in the hands and feet.
What does the research say about low B12 and mood?
A classic study in the New England Journal of Medicine described patients whose B12 deficiency caused neuropsychiatric symptoms, including mood and memory changes, even though they didn't have anemia, the usual red flag[1]. Clinical reviews list irritability, depression and cognitive changes among possible signs of deficiency[2].
The NIH notes that some studies have found associations between low B12 levels or low B12 intake and depression[3]. But association studies can't show whether low B12 causes low mood, or whether both are driven by something else, like poor appetite or an underlying illness.
What about B12 and anxiety?
You'll see B12 promoted for anxiety online, but there is little high-quality research on B12 and anxiety specifically. Most studies focus on depression and cognition. What we can say is that some symptoms of deficiency, such as fatigue, feeling unwell, heart palpitations from anemia, or tingling, can feel similar to anxiety or add to it[2]. If B12 deficiency is behind those symptoms, correcting it helps. If it isn't, B12 is unlikely to change anxiety.
Do B12 supplements help mood?
For people with normal levels, the evidence says probably not. A 2021 systematic review and meta-analysis of randomized trials found no overall effect of B12 supplementation on depressive symptoms or cognitive function in people without advanced neurological disorders[4].
For people who are genuinely deficient, treating the deficiency is important for their overall health, including the nervous system. That's why a blood test is the logical first step. For who is most at risk, see Vitamin B12 Deficiency: Signs, Causes, and Who Is Actually at Risk.
The honest summary
- B12 deficiency can cause mood, memory and nerve symptoms, sometimes without anemia.
- Low B12 and depression are linked in some studies, but that doesn't prove cause.
- In people with normal levels, B12 supplements haven't been shown to improve mood.
- If you're anxious or low, talk to a healthcare provider, who can check B12 along with everything else.
If you're in crisis or thinking about harming yourself, call or text 988 (the Suicide & Crisis Lifeline in the U.S.) or your local emergency number.
Our option
Vita Globe Vitamin B12 Gummies for Adults
If you and your provider decide B12 belongs in your routine, our B12 Gummies for Adults provide 1,000mcg of vitamin B12 (as cyanocobalamin) per two-gummy serving. B12 supports nervous system health and cellular energy production.* It is not a treatment for anxiety, depression or any other condition.
Frequently asked questions
Can B12 deficiency cause panic attacks?
There isn't good research showing B12 deficiency causes panic attacks. Some deficiency symptoms, like palpitations or fatigue, can feel similar to anxiety[2]. See a provider to find the cause.
How long does it take for B12 to help mood if you're deficient?
It varies. Some symptoms improve within weeks of treatment, while nerve-related symptoms can take longer. Your provider can monitor your progress.
Can B12 help brain fog?
If brain fog is caused by deficiency, treating it can help. If your levels are normal, supplements haven't been shown to improve cognition[4]. More in What Is B12 Good For?
Which vitamin deficiencies are linked to depression?
Low B12 has been studied in relation to depression[3], and so have other nutrients such as folate. A provider can check the relevant levels.
Sources
- Lindenbaum J, Healton EB, Savage DG, et al. Neuropsychiatric disorders caused by cobalamin deficiency in the absence of anemia or macrocytosis. N Engl J Med. 1988;318(26):1720-1728. doi:10.1056/NEJM198806303182604
- Stabler SP. Vitamin B12 deficiency. N Engl J Med. 2013;368(2):149-160. doi:10.1056/NEJMcp1113996
- Office of Dietary Supplements, National Institutes of Health. Vitamin B12: Fact Sheet for Health Professionals. Updated July 2, 2025. ods.od.nih.gov
- Markun S, Gravestock I, Jäger L, Rosemann T, Pichierri G, Burgstaller JM. Effects of vitamin B12 supplementation on cognitive function, depressive symptoms, and fatigue: a systematic review, meta-analysis, and meta-regression. Nutrients. 2021;13(3):923. doi:10.3390/nu13030923
- Green R, Allen LH, Bjørke-Monsen AL, et al. Vitamin B12 deficiency. Nat Rev Dis Primers. 2017;3:17040. doi:10.1038/nrdp.2017.40
About the Vita Globe Editorial Team
The Vita Globe Editorial Team researches and writes our wellness content, working from peer-reviewed research, systematic reviews and guidance from bodies such as the NIH and the FDA. We cite our sources inline and update articles when the evidence changes.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. This article is for informational purposes only and is not a substitute for medical advice. Talk to your healthcare provider before starting any new supplement, particularly if you are pregnant, nursing, taking medication, or caring for a child.
