Abstract | November 8, 2021

Role of B12 and its Metabolites in Depression and Suicidality: A Review

Presenting Author: Sara A Khan, Bachelor of Science, Medical Student, 3rd Year, Nova Southeastern University Dr. Kiran C. Patel College of Allopathic Medicine, Davie, FL, Davie, FL

Coauthors: Shivani Kaushal, BS, Medical Student, 3rd Year, Nova Southeastern University Dr. Kiran C. Patel College of Allopathic Medicine, Davie, FL; Brian Blum, DO, Psychiatry, PGY3, HCA Healthcare, Aventura, FL; Charmi Balsara, MD, Psychiatry, PGY2, HCA Healthcare, Aventura, FL; Clara Alvarez Villalba, MD, Program Director, Psychiatry, HCA Healthcare, Aventura, FL.

Learning Objectives

  1. Describe nutritional deficiencies that have been identified in patients with depression;
  2. Discuss the contribution of low folate and B12 levels on the severity of depressive symptoms.

Background/Knowledge Gap: Supplementation for vitamin deficiencies is an increasingly relevant consideration in major depressive disorder (MDD) treatment. While associations between MDD and B12 have been established, less is known about the specific criteria of depression (e.g., suicidality, anhedonia) in which vitamin B12 may play a role, which could aid in optimization of depression treatment. 

Methods/Design: A literature search was conducted through querying the PubMed database for associations between depression and B12, folate, or homocysteine levels with the following criteria: ((depression) AND (B12)) OR ((depression) AND (folate)) OR ((depression) AND (homocysteine)). A more focused search was then carried out by focusing on suicidality, a specific depressive symptom, with the following criteria: ((suicide) AND (B12)) OR ((suicide) AND (folate)) OR ((suicide) AND (homocysteine)). Two independent reviewers determined eligibility of articles in each search. 

Results/Findings: PubMed query with search criteria for associations between B12 and depression yielded 1415 total results. Results from relevant studies in this search generally supported an association between depression and B12, folate, or homocysteine levels, but no clear consensus on the roles of these metabolites in depression. Search criteria with suicidality yielded 80 total results, with only three studies evaluating the association between suicidality and B12 or its metabolites. Together, these studies suggested an association between suicidal ideation and low B12, folic acid, and fatty acid levels; an ambiguous association between high homocysteine levels and suicidal ideation; and an association between geriatric depression and low folate/B12 & high homocysteine levels, with commentary on higher levels of suicidal ideation in the depressed elderly population. 

Conclusions/Implications: This review highlights the necessity of more focused research into the roles of metabolites such as B12, folate, and homocysteine in depression and, more specifically, suicidality. Elucidating an association between B12 metabolite levels and suicidality could reveal another tool for suicidal patients, with supplementation potentially providing an adjunct to antidepressants, improving symptoms, and/or reducing risk of future suicide attempts.