One study found that blood levels of folic acid were much lower among people with depression than in people who were not depressed. Findings like these have suggested a link between low folic acid levels and depression. If low levels of this vitamin lead to depressive symptoms, it seems logical to conclude that giving folic acid supplements to people with depression will help their recovery. However, research shows that the connection is not that simple.
Folic acid, which is needed to make DNA and RNA, the building blocks of genes and an important component of cells, is also quite active in the brain and central nervous system. It affects the production of certain essential compounds and neurotransmitters—substances that carry messages to different parts of the brain.
For example, folic acid deficiency leads to lower levels of S-adenosylmethionine (SAMe) in the brain. Some research has suggested that supplementation with SAMe can play a positive role in the treatment of depression. One possible theory is that low folic acid levels leads to low SAMe, which increases symptoms of depression. By improving folic acid status, SAMe increases, and depressive symptoms drop.
A review of 11 studies involving 15,315 people found an association between low folic acid levels and depression, adding to the evidence that folic acid deficiency is a risk factor for depression.
Researchers have also focused on people who are being treated for depression. For example, in one study, 127 people with severe depression were randomized to receive 500 micrograms (mcg) of folic acid daily or placebo along with their antidepressant medication fluoxetine for 10 weeks. The women in the treatment group experienced a significant improvement in their symptoms. Interestingly enough, the men taking the folic acid did not have the same results. While it is hard to say exactly why this happened, the men may have not had low folate levels or needed a higher dose of folic acid to experience the benefits.
In another study, 909 older adults with mild depression where randomized to receive different treatments, including a group that took folic acid and vitamin B12 daily for two years. The evidence showed, though, that the 2 vitamins were no better than the placebo in improving depression.
Depression is a serious condition that requires careful, ongoing treatment with talk therapy, medication, or a combination of the two. The research looking into folic acid and depression is still emerging. It may be reasonable to ask your doctor about folic acid since it may be helpful when taking selective serotonin reuptake inhibitors (SSRIs).
If you are living with depression, talk with your doctor about folic acid. If you are deficient, your doctor may recommend taking a daily multi-vitamin and mineral supplement, as well as increasing your intake of foods rich in this vitamin, such as:
Note: Do not take more than 400 micrograms daily of folic acid daily because a high intake may hide a serious vitamin B12 deficiency.
Keep in mind that a deficiency of folate might increase the risk of heart disease and stroke. In addition, for women considering pregnancy, sufficient folic acid intake can help decrease the risk of having a baby with a neural tube defect, such as spina bifida. Folic acid certainly is a vitamin worth getting your fair share of. It is just not yet clear if it can also help improve your mental state.
Depression & Bipolar Support Alliance
National Alliance for the Mentally Ill
Canadian Psychological Association
Health Canada Food and Nutrition
Coppen A, Bailey J. Enhancement of the antidepressant action of fluoxetine by folic acid: a randomised, placebo controlled trial. J Affect Disord. 2000;60:121-130.
Depression. EBSCO DynaMed website. Available at:http://www.ebscohost.com/dynamed. Updated February 11, 2016. Accessed February 15, 2016.
Folate. EBSCO Natural and Alternative Treatments website. EBSCO Health Library website. Available at: http://www.ebscohost.com/healthLibrary. Updated August 2013. Accessed February 15, 2016.
Folate. Office of Dietary Supplements website. Available at: http://ods.od.nih.gov/factsheets/folate-HealthProfessional. Updated December 14, 2012. Accessed February 15, 2016.
Gilbody S, Lightfoot T, Sheldon T. Is low folate a risk factor for depression? A meta-analysis and exploration of heterogeneity. J Epidemiol Community Health. 2007;61(7):631-637.
S-Adenosylmethionine (SAMe). EBSCO Natural and Alternative Treatments website. EBSCO Health Library website. Available at: http://www.ebscohost.com/healthLibrary. Updated August 2013. Accessed February 15, 2016.
Walker JG, Mackinnon AJ, Batterham P, et al. Mental health literacy, folic acid and vitamin B12, and physical activity for the prevention of depression in older adults: randomised controlled trial. Br J Psychiatry. 2010;197(1):45-54.
Last reviewed February 2016 by Michael Woods, MD