B vitamins, B-1, B-2, B-3, B-5, B-6, B-9 and B-12, are water soluble vitamins that play critical roles in human cell metabolism. They either serve as a co-enzyme for critical cell metabolic processes, or as a precursor needed to generate such processes. They also play a role in producing chemicals in the human brain that affect mood and other functions. As such, deficiencies in any of the B vitamins can lead to mood disorders such as depression.
Vitamin B-12, or Cobalamin, in particular, has been linked to depression. B-12 is a co-enzyme that is involved in the metabolism of every single cell in the human body. It is critical to amino acid metabolism, fatty acid metabolism, and the regulation and synthesis of DNA. It is also essential for the cellular metabolism of lipids, carbohydrates and proteins, as well as the production of proteins, nerve sheaths and bone marrow blood cells. Finally, it serves as a co-enzyme for certain intermediary metabolic processes.
Vitamin B-12 deficiencies can result in depression, peripheral neuropathy, cognitive deficits, memory loss, mania, psychosis, elevated homocysteine levels (linked to increased risk of stroke and heart attack), macrocytic anemia (blood with insufficient concentrations of hemoglobin) and in extreme cases, paralysis. Low levels of B-12 can result from poor diet or digestive/vitamin absorption issues that those who suffer from celiac disease or Crohn’s disease experience, and those who have absorption issues resulting from gastric bypass surgery. Certain medications, such as Metformin (taken for pre-diabetic and diabetic conditions), can also inhibit vitamin absorption. A simple blood test can answer the question of whether someone is suffering from a B-12 deficiency.
Although the specific role of B-12 deficiencies in the development of depression is not fully understood, the correlation is strong enough to suggest that they should be ruled out as a potential cause or contribution to symptoms of depression. Moreover, the human body can’t make B-12, but an average adult needs 2.4 micrograms per day. If a B-12 deficiency is detected, one obvious way to address is to focus on diet. Animal based foods such as poultry, fish, eggs, lean meats, and low or fat-free milk are rich with B-12. Breakfast cereals fortified with B-12 can also be a good source of the vitamin. Plant based foods, however, will not help. Plants, like humans, can’t produce B-12 on their own.
Daily dietary supplements can also be an option for boosting B-12 levels, but consult with a health care provider before going that route. Vitamin supplements, including B-12, can interact with some medications so there may be unintended consequences. Daily dietary supplements can also cause some transient side-effects such as insomnia, restlessness and nausea, so if they are a good option, dosages may need to be sorted out.
Finally, it is important to remember that although B-12 deficiency may play a role in any one person’s development of depression, efforts to correct the deficiency should be used in conjunction with, rather than as a substitute for, proven depression treatments like psychological counseling and antidepressant therapies.