How Vitamin B12 Deficiency Can Cause Depression and Anxiety

Understanding Vitamin B12 

Vitamin B12 is a vital nutrient necessary for the proper functioning of the brain and nervous system. It plays a crucial role in red blood cell formation, neurological function, and DNA synthesis and helps to keep your nerves and brain healthy [1]. A deficiency in Vitamin B12 can lead to a range of mental health disorders, including depression and anxiety. Numerous studies have shown an association between low serum levels of vitamin B12 with increased risk of depressive symptoms. Low intake has been linked with a higher risk of depression among women [2].

Vitamin B12 Deficiency

Having adequate vitamin B12 serum levels may be a protective factor against the development of Parkinson’s disease [3]. There are several mechanisms to explain how vitamin B12 could delay or prevent the onset of Parkinson’s, as well as depressive symptoms, for example, through the regulation of high homocysteine levels [3]. The early detection of vitamin B12 deficiency has a link with reducing the risk of Parkinson’s. 

Vitamin B12 deficiency may relate to other factors, such as poor absorption, advanced age, following a vegan diet, and not consuming enough vitamin B12-rich foods [4]. For proper absorption of vitamin B12, hydrochloric acid is required. Proton pump inhibitors, histamine H2 blockers, and heartburn medications meant to lower the acidity in the stomach can contribute to B12 deficiency. 

Can Vitamin B12 Deficiency Cause Depression and Anxiety?

Research has shown that individuals with low levels of Vitamin B12 are more likely to experience symptoms of depression and anxiety. This is because Vitamin B12 is involved in synthesizing serotonin, a neurotransmitter responsible for regulating mood. When serotonin levels are low, it can lead to feelings of sadness, irritability, and anxiety [6]. Vitamin D can also be critical for improving depression. 

Low vitamin B12 levels are associated with having increased levels of homocysteine, contributing to higher levels of depression [2,3]. Elevated homocysteine has been linked with depression in multiple studies [3]. When the body has increased homocysteine, it can disrupt cognitive ability and affect mood leading to depressive symptoms [5].

Vitamin B12 Deficiency Symptoms

Deficiency may result in various disturbances such as hematological, neurological, and psychiatric problems, observed as the following symptoms: 

• Feeling tired/weak or confused

• Tingling or numbness in fingers and toes

• Constipation, balance issues

• Depression and cognitive issues 

• A swollen, inflamed tongue

• Anemia 

Deficiency symptoms tend to manifest gradually over a few years, and it is recommended to check blood serum levels for early detection [7].

Are you Vegan/Vegetarian?

Individuals following a vegan or vegetarian diet are at higher risk of developing vitamin B12 deficiency [7]. Vitamin B12 is naturally found in animal products. Individuals can be prone to multiple micronutrient deficiencies when excluding vitamin B12-rich foods. If you are vegan or vegetarian, fortified food is a good source of vitamin B12 [1], shown to reduce deficiency rates [7]. 

The amount of vitamin B12 your body needs is measured in micrograms (mcg), and adults need approximately 2.4 mcg daily [1].

Preventing Deficiency and Supporting Mental Health

Foods sources of Vitamin B12

• Meat, poultry, and eggs

• Beef

• Fish (trout, salmon, tuna, and sardines)

• Dairy products

• Fortified foods, like cereal, non-dairy kinds of milk, and soy products 

• Nutritional yeast

The best sources of vitamin B 12 include liver, beef providing 60 mcg for 3 ounces, and clams with 84 mcg for 3 ounces. Other good sources include salmon with 3 mcg for 3 ounces and tuna with 2.5 mcg for 3 ounces [1]. 

Supplemental forms of Vitamin B12 

Although it is recommended to get vitamin B12 from your food, supplementation is a good option. Supplementing with Vitamin B12 may delay the onset of depression and has improved the effect of antidepressants [5]. 

There are various forms of supplementation:

• Oral medications

• Intramuscular injections

• Nasal spray

Supplementation can be taken for shorter periods until the individual reaches optimal levels in the blood or for longer, depending on the severity [4]. Different forms of supplemental cobalamin (B12) are on the market, and methylated forms are growing in popularity. 

Conclusion 

Vitamin B12 is an essential nutrient that serves many functions throughout the body. Having low levels of vitamin B12 in the body is associated with a high risk of developing depression. Maintaining adequate vitamin B12 serum levels may help improve mental health by decreasing the risk of depression and anxiety. 

If you find out you have a vitamin B12 deficiency, begin implementing diet changes by incorporating more B12-rich foods with your meals. If you are vegan or vegetarian, consider vitamin supplementation and increasing foods fortified with vitamin B12. 

In addition to addressing the deficiency, it is also important to seek professional help if you are experiencing symptoms of depression or anxiety. A healthcare provider can diagnose properly and recommend appropriate treatment options, including therapy, medication, or a combination. Nutrition interventions are growing in popularity. 

By understanding the role of Vitamin B12 in mental health and addressing any deficiencies, individuals can improve their overall well-being and reduce the risk of mental health disorders. At Wise Mind Nutrition, we believe it’s important to prioritize mental health and seek adequate support when needed! We’d love to be your go-to resource.

Blog Contributor

Yolanda Meza

References

1. Vitamin B12 Foods List (2018). - Nutrition Care Manual. (n.d.). https://www.nutritioncaremanual.org/ 

2. Sánchez-Villegas A, Doreste J, Schlatter J, Pla J, Bes-Rastrollo M, Martínez-González MA. Association between folate, vitamin B(6) and vitamin B(12) intake and depression in the SUN cohort study. J Hum Nutr Diet. 2009;22(2):122-133. doi:10.1111/j.1365-277X.2008.00931.x

3. Flores-Torres MH, Christine CW, Bjornevik K, et al. Long-Term Intake of Folate, Vitamin B6, and Vitamin B12 and the Incidence of Parkinson's Disease in a Sample of U.S. Women and Men. Mov Disord. 2023;38(5):866-879. doi:10.1002/mds.29383

4. Staff, H. H. P. (2022, March 23). Vitamin B12 deficiency can be sneaky and harmful. Harvard Health. https://www.health.harvard.edu/blog/vitamin-b12-deficiency-can-be-sneaky-harmful-201301105780 

5. Sangle P, Sandhu O, Aftab Z, Anthony AT, Khan S. Vitamin B12 Supplementation: Preventing Onset and Improving Prognosis of Depression. Cureus. 2020;12(10):e11169. Published 2020 Oct 26. doi:10.7759/cureus.11169

6. Russell-Jones, G. (2022, May 7). Vitamin B12 deficiency and depression: What is the mechanism?. ASEAN Journal of Psychiatry. https://www.aseanjournalofpsychiatry.org/articles/vitamin-b12-deficiency-and-depression-what-is-the-mechanism-87542.html 

7. Bakaloudi DR, Halloran A, Rippin HL, et al. Intake and adequacy of the vegan diet. A systematic review of the evidence. Clin Nutr. 2021;40(5):3503-3521. doi:10.1016/j.clnu.2020.11.035