Vitamin B12 & Depression Diagnosis

Depression can cause symptoms of sadness or lethargy.
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Depression is a chronic mood disorder that impairs daily functioning. Although the exact cause of clinical depression isn't known, some researchers speculate that a vitamin B-12 deficiency may play a role. Adding more foods that are high in vitamin B-12 to your diet may help reduce some depressive symptoms. Consult your physician or psychiatrist if you are feeling depressed for exact treatment recommendations.


Vitamin B-12 is a water-soluble vitamin that is primarily available in animal proteins, such as beef, poultry and seafood. The Institute of Medicine recommends that adults consume 2.4 micrograms of vitamin B-12 each day. Because your body uses vitamin B-12 to make and maintain red blood cells, a deficiency can cause anemia. Vitamin B-12 deficiency can cause fatigue symptoms, neurological symptoms and gastrointestinal symptoms. Those most at risk of a deficiency include vegetarians, older adults and people with certain gastrointestinal conditions that may affect how they absorb nutrients.

Potential Link

Vitamin B-12 and folate, another B-vitamin, help your body make S-adenosylmethionine, or SAMe. SAMe is a methyl compound that is found in nearly every tissue and fluid in your body. Although researchers are not sure, some believe that SAMe helps your body make and metabolize neurotransmitters, such as serotonin, according to the University of Maryland Medical Center. A vitamin B-12 deficiency can affect your body's production of SAMe, which, in turn, may inhibit the production of serotonin.


A 1997 review published in “Comprehensive Psychiatry” examined past research on psychiatric illnesses and folate and vitamin B-12 deficiencies. The review found that as many as 30 percent of patients hospitalized for depression were deficient in vitamin B-12. Many research studies have specifically looked at older adults. A 2000 study published in the “American Journal of Psychiatry” found that women older than 65 who reported symptoms of depression were twice as likely to have deficient levels of vitamin B-12 compared to those not reporting depression.


Because there are many different causes of depression, you should talk to a qualified medical provider about your symptoms. Your doctor may prescribe an anti-depressant or therapy to help you cope with your mood disorder. If you think you are deficient in vitamin B-12, consult your physician before taking any vitamin B-12 supplements. Vitamin B-12 supplements can interact with certain medications. Only your physician can determine if you are low in the vitamin.

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