Dr. David Henderson
December 14, 2009
David Henderson

I am often asked about the benefits of supplements for improving mental health. May individuals lean toward supplements because they are “natural”, though unless you are getting these natural supplements directly from your diet, they are not really natural at all. They are still manufactured and processed just like everything else. Because supplements are not regulated by the FDA, it is very hard to know exactly what you are getting in any given batch. On top of this, very few studies have shown significant benefit from anything other than a once daily vitamin like centrum silver. Still, it is worth talking to your doctor about if you have specific questions or concerns. We do know that vitamins and minerals play a vital role in our bodies physiology. This is why I always recommend a well balanced diet with at least 30 minutes of exercise each day. Here are a few of the vitamins that have effects on the brain that are in most once daily supplements:

Vitamin B1 (thiamine).

Thiamine deficiency commonly results in psychiatric symptoms including irritability and depression, fearfulness, agitation and emotional instability.  Severe thiamine deficiency induced by chronic alcoholism, referred to as Wernicke-Korsakoff syndrome, is well known to be associated with a large array of psychiatric and cognitive symptoms including disorientation.

Vitamin B2 (riboflavin).

Riboflavin is essential to many pathways involved in the metabolism of protein, fats and carbohydrates as well as for the activity of numerous antioxidant enzymes. Relating to riboflavins antioxidant function, riboflavin deficiency has been associated with oxidative stress. Major depression has also been associated with oxidative stress which may play a role in its development.

Vitamin B6 (pyridoxine).

 Lower levels of pyridoxal phosphate, the biochemically active form of B6, are significantly correlated with higher levels of depression. Irritability and confusion have also been reported as symptoms of B6 deficiency and chronically B6 deficient individuals were also found to be significantly more anxious.

Pyridoxine is required as a coenzyme for the synthesis of serotonin, dopamine and GABA. Pyridoxine is also required for carbohydrate metabolism and other aspects of amino acid metabolism.


Depression is a common symptom of folate deficiency. Folates basic functions include methylation and DNA synthesis. Lower central nervous system levels of 5-hydroxytryptamine (serotonin) are also documented in folate deficiency.  The most likely explanation for the association between folate status and psychiatric symptoms is its connection with monoamine metabolism via methylation, although other functions are also likely relevant.

Vitamin B12 (cobalamin).

Depression is a common early psychiatric manifestation of B12 deficiency. Other symptoms include mania and psychosis, slowing of mental processes, confusion and memory defects. B12 deficiency also causes folate to be ‘trapped’ in a form not available to perform its function.

Vitamin C (ascorbic acid).

Vitamin C is a cofactor for dopamine beta-hydroxylase, which is involved in the conversion of dopamine to norepinephrine, and a cofactor for tryptophan-5-hydroxylase required for the conversion of tryptophan to 5-hydroxytryptophan in serotonin production. Vitamin C also has broad-spectrum antioxidant properties and is essential for the mitochondrial metabolism of fats.


Magnesium deficiency can cause depression, behavior and personality changes, apathy, irritability and anxiety. Magnesium is required by over 300 chemical reactions in humans.


Psychiatric manifestations of zinc deficiency include behavioural disturbances, depression and mental confusion. Within major depression populations, lower zinc levels correlate with higher depression severity.

Zinc is involved in such functions as antioxidant defence, gene expression, nerve impulse transmission, thyroid function, digestion and a large array of other functions. Zinc is found in high concentrations in hippocampal and cortical neurons. Zinc is also an inducer of brain derived neurotrophic factor is an antagonist of the NMDA-receptor  and is required for GABA metabolism.


A number of studies suggest that fish oil supplements may be an effective add-on (adjuvant) therapy for depression. Fish oil is a good source of omega-3 fatty acids. Fatty acids have been shown to play an important role in brain function as well as normal growth and development. Some research has suggested that people who have depression have low blood levels of eicosapentaenoic acid (EPA), a fatty acid found in fish oil.

As I said at the beginning of the post, a daily supplement with a well-balanced diet and exercise is the most natural way to stay healthy. If you are curious, however, about extra supplements, consult your doctor before starting any new dietary or herbal supplement to treat depression, especially if you take other medications.

Mann J & Truswell AS. Essentials of Human Nutrition. 2nd edition. New York: Oxford University Press; 2002.