A man suffering from depression sitting in a chair

9 Nutrient Deficiencies That Can Cause Depression

Depressed man sitting in a chair - 9 Nutrient Deficiencies That Can Cause Depression


Working in Canada’s largest hospital for mental health and addiction, I absolutely appreciate the impact of lifestyle (nutrition and diet, stress management, sleep and leisure) on mental health.


This doesn’t just include mood disorders like depression and anxiety or seasonal affective disorder (SAD).


There’s also no shortage of research on the role and impact of nutrition on other psychiatric illness like schizophrenia, bipolar disease and more.


As a nutrition educator, I give presentations on nutrition and brain health, as well as, food and mood.


I review key nutrients that are absolutely vital for brain health.  What you eat and drink directly affects the structure of your brain which, in turn, influences your brain’s function. This includes both the synthesis and function of neurotransmitters, as well as, the presence, or absence of inflammation.


Many of the patients I work with are in recovery for drug [prescription and illicit] and alcohol addiction. Most of them are also dealing with depression and anxiety. I also work with adults who are only dealing with mood disorders (no addiction issues).


How to cope with depression

It’s amazing to me how most psychiatrists fail to appreciate the role of nutrition in mental health, including the connection between nutrition and depression.


It’s not only common sense, but it’s backed up by research (1, 2, 3). No amount of medication can make up for a crappy diet.


There is no biological or physiological need for common ‘mood stabilizers’ such as Pristiq, Cymbalta, Wellbutrin, etc.


There is however, a biological need for nutrients such as vitamins, minerals, essentially fats & antioxidants for both overall health and mental health.


Blueberries - 9 Nutrient Deficiencies That Can Cause Depression


It’s naive and unreasonable for anyone, doctor or patient, to think that they can be their best self, or have optimal psychological and emotional well-being without addressing their underlying biology.


Whether you’re using talk therapy, medication, or both to manage your depression, you’ll get more for your efforts if you tend to your physical health as well. This includes the health of your brain and your brain needs lots of nutritional TLC too.


If anyone thinks I’m saying that medications don’t have a time and place in mental health management is dead wrong. They do, but it’s important not to lose sight of the big picture


No amount of Paxil, Celexa, Lexapro or Viibryd (Vilazodone) will make up for an inadequate intake of vitamins and minerals.


Food And Mood

There are dozens and dozens of neurotransmitters produced by your body. What is a neurotransmitter? It’s a chemical that is released at the end of a nerve fiber. The neurotransmitter jumps across (in effect) to the next neurotransmitter enabling all your brain cells to communicate.


This regulates emotions, allows for learning, memory formation, giving a sense of pleasure, focus and attention depending on the neurotransmitter in question.


The three main ones that are talked about in mental health are:

  • Serotonin
  • Dopamine
  • Norepinepherine
  • GABA

This is because the bulk of the research has focused on them and the medications used in mental, influence their metabolism.


The building blocks of neurotransmitters are amino acids. You get amino acids from the digestion and breakdown of  dietary protein. The critical players in the synthesis and function of neurotransmitters however are vitamins & minerals.


Changing Diets – Changing Minds


The analogy I like to use is a factory beltline that needs a certain number of employees to show up for maximum output/production. If half the staff call in sick, production suffers.


Likewise for neurotransmitter production and function; you need optimal amounts of nutrients on a daily basis. If they are lacking in the diet, mood can be disrupted. This can set the stage for the development of depression and anxiety. Poor nutrition can also aggravate and worsen any existing mood and/or psychiatric disorder.


Spinach white washed table 2 - 9 Nutrient Deficiencies That Can Cause Depression


Brain food

Feeding you brain is easier than you think. By improving your diet and using targeted supplements where indicated, you can improve your brain health while supporting your mood at the same time. The following are the heavy-hitters when it comes to using nutrition for depression support.

Omega-3 fats

About 15-20% of the total fat in your brain, ideally, would be omega-3s. I say ideally because many don’t get enough of this critical nutrient. Of the total amount of omega 3 fats in the brain, 92% of it is DHA omega 3 (4).


The DHA omega-3 fat is critical for brain cell [neuron] structure. If the diet doesn’t have enough of it, other fats have to take its place. If it’s trans fat, that spells trouble.


Omega-3 Fatty Acids in the Treatment of Psychiatric Disorders


Trans fat increase inflammation and this increases the risk for depression and poor cognitive function (5, 6).


Omega 3 EPA helps support mental health and depression in a couple of ways. EPA supports neuron function and reduces blood viscosity. When blood flows freely, your brain cells get the oxygen and nutrients they need better. Omega 3 EPA also acts like tricyclic antidepressants by modulating ‘calcium-ion’ flux (7).

Sardines - 9 Nutrient Deficiencies That Can Cause Depression

EPA also helps to reduce inflammation. which is why research supports the role of omega-3 fats in improving symptoms of depression [and other mood disorders]. Inflammation is now sense as a risk factor for, and aggravating effect on depression (8, 9).


While not fully understood in its role in mental health, EPA’s and DHA’s ‘sibling’, DPA omega 3 is another important nutrient. It also helps to lower inflammation and when consumed along with EPA and DHA, DPA increases the uptake of all three by your body’s cells and tissues.


Food sources of omega 3 fats are fish and seafood, especially fatty fish, omega-3 fortified eggs and supplements. Of note, be sure to consider your omega 6 to omega 3 ratio. You don’t want to over consume omega 6 at the expense of omega 3.



Iodine can be thought of as the new vitamin D.  Iodine plays a central role in mental health.


It’s an up and coming nutrient but not in a good way because it’s one mineral that most of use are not getting enough of. Ideally iodine should be known for all the good it does like it’s role in reducing the risk for depression rather than being known as a nutrient of concern.


Iodine is critical for a healthy thyroid, the master of metabolism [i.e. cellular fitness]. It has largely been removed from the food supply and whereas we used to get about 800 mcg per day, most are lucky to get between 138 to 350 mcg per day.


The Silent Epidemic of Iodine Deficiency


While this can stave off an overt deficiency, it likely won’t be enough to move people into the functional range where physiological processes are optimal including mental health. Be sure you’re intake of iodine is optimal.


Good food sources of iodine include seaweed, cod, iodized salt. Other moderate food sources include milk, yogurt, and eggs.


Good quality supplements should provide the RDA of 150 mcg per dose as a foundation.



Zinc is a tireless ally. It is involved in over 250 separate biochemical pathways, or reactions. These reactions support just about every function needed for overall health, not the least of which is a strong immune system and mental well-being (10, 11).


Zinc. An Antidepressant


Zinc is critical for neurotransmitter production and function (12, 13, 14). A review of the role of 3 minerals, zinc, selenium, and magnesium were looked at for their role in depression. Findings support the importance of adequate consumption of micronutrients in the promotion of mental health (15).


Oysters - 9 Nutrient Deficiencies That Can Cause Depression


Effects of Zinc Supplementation in Patients with Major Depression. A Randomized Clinical Trial


Unlike calcium, phosphorus and magnesium which is stored in your body in large amounts, zinc isn’t. You need a steady and reliable source everyday to the most that zinc has to offer.


Of note for vegetarians and vegans, legumes and grains have compounds that keep zinc from being fully absorbed by the body. For this reason, vegetarians might need to eat as much as 50% more zinc than the recommended amounts.


Best food sources include oysters, crab, beef, lamb, pork, dark meat, and chicken. Next best are legumes, cashews and a good quality multivitamin with minerals will have some as well.



Like zinc, magnesium is required for over 300 separate biochemical pathways, or reactions. What is magnesium good for? It’s needed for healthy bones and teeth, reduced anxiety, lower blood pressure, reduced risk for diabetes to name a few.


Most of us only get about half of the recommended amount: 420 mg per for men and 320 mg for women. There are several reasons for this including our intake of mostly refined foods, decreased soil levels, and medications that interfere with magnesium absorption (15).


Many are dealing with health issues that put them at risk for magnesium deficiency as well such as prediabetes or insulin resistance, diabetes, moderate to heavy alcohol consumption, and anyone with gastrointestinal disorders which can decrease absorption (16).


Pumpkin seeds - 9 Nutrient Deficiencies That Can Cause Depression


Magnesium is needed to activate the enzymes needed for serotonin, dopamine and norepinepherine production. Also, whereas calcium and glutamate are excitatory in the neuron, magnesium is an ‘antagonist’ to them. Magnesium in this sense is calming bring balance. Not too stimulated, not too under-stimulated.  If there’s not enough magnesium in the brain cells and synapses, they won’t work as well and this leads to depression.


Rapid Recovery from Major Depression using Magnesium Treatment


What foods contain magnesium? Good food sources include nuts & seeds, dark green vegetables, avocado, and fish with bones. Not to be outdone are blackstrap molasses, lima beans, whole grains, bran and dark chocolate. Pumpkin seeds are a standout – they contain a lot of magnesium.


Supplements are typically needed to help people meet their minimum daily requirement on a consistent basis. By increasing magnesium intake, supplements will move people with depression beyond just preventing a clinical magnesium deficiency. It will help them have enough magnesium on board so their brain and neurons can function optimally.


Vitamin D

Anyone who knows me or is familiar with this blog knows that vitamin D is my baby and that we don’t get enough of this kick-ass vitamin.


This is especially true in Canada. From mid-October till mid-April, the sun is just too low in the sky to produce any vitamin D in your skin. The rule of thumb is: the UVB index needs to be 3 or higher and the sun needs to be high enough in the sky. The easiest way to know if it is, is if your shadow is shorter than you are tall. Easy huh?


Vitamin D Supplementation for Depressive Symptoms. A Systematic Review and Meta-Analysis of Randomized Controlled Trials.


Vitamin D infographic 300x300 - 9 Nutrient Deficiencies That Can Cause Depression


The brain loves vitamin D and has loads of vitamin D receptors just waiting for their payload. Vitamin D deficiency has not only been linked to depression, but anxiety, SAD, and dementia as well. Vitamin D is needed by your amygdala, the part of the brain that regulates emotion.


What’s the link between vitamin D and depression?


Supplementation is the only viable option to raise vitamin D levels to where they need to be for optimal, overall health but as well to lower the risk for depression.


Most people can maintain levels to prevent vitamin D deficiency and vitamin D deficiency symptoms such as rickets and osteomalacia. At least during the spring and summer over deficiency can be avoided with some casual safe sun exposure. But food alone will not prevent low levels during the late fall and winter.


The best resources on the net for all things vitamin D are the Vitamin D Council, GrassrootsHealth and for the technically and scientifically inclined, VitaminDwiki. So much great information, so have at it!


Best food sources of vitamin D are fluid fatty fish like sardines, salmon, mackerel, herring. Also trout, fluid milk and eggs.


Like iodine, selenium is needed for good thyroid function.


Often, just increasing selenium intake can improve early symptoms of low thyroid function. A healthy thyroid supports mental health including reducing the risk for depression.


Selenium is also needed to convert the inactive thyroid hormone T4 to the active form T3. This conversion primarily occurs in the liver, the rest occurs in the gut and then in other tissues throughout the body.


When people are put on thyroid hormone replacement medication, it’s only T4. It’s assumed that people are able fully convert the medication form of T4 to T3 efficiently.


Shrimp 1 - 9 Nutrient Deficiencies That Can Cause Depression



Sadly this isn’t always the case which is why many people who are put on Synthroid or Levothyroxine don’t feel better. Their depression remains or gets worse despite their ‘thyroid’ blood work being normal, e.g. lower TSH.


Ensuring you’re getting enough selenium is a good first step when it comes to assessing your nutrient intake when it comes to managing and/or reducing your risk for depression.


Optimal Serum Selenium Concentrations Are Associated with Lower Depressive Symptoms and Negative Mood Among Young Adults


Selenium is needed to make your body’s master antioxidant and detoxifying compound glutathione. Glutathione is actually the major brain antioxidant.


Increasing glutathione has been shown to improve depression  because glutathione reduces inflammation in the brain. Glutathione is also needed to protect the thyroid gland. As it makes thyroid hormone, it produces a lot of hydrogen peroxide and glutathione protects against this.



Good food sources Brazil nuts, nuts, sunflower seeds, fish, oysters, ham, shrimp, liver and chicken.


Iron deficiency is more common in women than men due to losses via menstruation.


The most common form of anemia is iron deficiency. It’s symptoms are similar to depression: fatigue, irritability, apathy, brain fog, lack of motivation and appetite.


Having anemia-related symptoms like these could lead to depression given their impact on quality of life. While anemia may not be the cause for depression, a lack of consideration to iron intake could result in a misdiagnosis. Treatment for depression when it’s an issue of anemia would aggravate depressive symptoms.


Anxiety is another consequence that can stem from having low iron levels. If you have low iron levels, it could trigger panic symptoms given the broad symptoms of anemia, leading to a panic attack. Increased anxiety can lead to depression and vice versa. These two often go hand-in-hand.


Eating vitamin C-rich foods along with iron-rich foods helps to increase the absorption of iron. For women, a multivtamin with minerals typically provides 8 to 12 mg of iron. Men should choose a multi that is iron-free.


Good food sources are beef, pork, lamb, dark meat chicken, eggs, liver, oysters and white beans.


B complex vitamins typically includes about 11 B vitamins all of which are involved in neurotransmitter production and function. B vitamins have many nervous systems benifits.


Some, like vitamin B12 are needed to help maintain brain mass, a.k.a. prevent brain shrinkage, a cause of dementia. A classic B12 deficiency symptom is depression. A symptom that is not really consider in mental health, certainly not in the mental health hospital that I work in.


What’s very interesting is the fact that deficiencies in all of the B vitamins have a psychiatric component. Mood disorders, psychoses, depression, anxiety, memory issues, cognitive function are all negatively impacted by vitamin B deficiencies.


We can’t store B vitamins in our body like we can vitamins A, D E & K. We need a steady supply of they daily to satisfy all our our body’s requirements  for them.


Quinoa Porridge 300x200 - 9 Nutrient Deficiencies That Can Cause Depression


Other important B vitamins for mental health include B1, B6, B3, and folate.


Folate, along with B12 and B6 help to lower levels of homocysteine, a by-product of protein metabolism. Elevated levels of homocysteine increase the risk for depression because homocysteine drives inflammation. Inflammation is now recognized as a risk factor for depression. In fact, most of the mood stabilizers, new term for ‘antidepressants’ work for the very fact that they lower inflammation in the brain.


A Food-Mood Connection: B Vitamins and Depression


Folate is another superstar B vitamin that works with vitamin B12 and B6 to support mental health. In order for dietary folate to be effective though, it needs to be converted to its active form 5-MTHR.


However about 66% of the population don’t do this effectively because they have a mutation in the gene 5-MTHF reductase. This gene should turn on an enzyme (protein) whose job is to convert folate into 5-MTHF.  For folks with this mutation, it puts them at a 180% increased risk for folate deficiency or a least a functional deficiency – meaning their folate and cellular machinery isn’t functionally optimally.


Best food sources are whole grains, nuts & seeds, dark green vegetables, legumes, eggs, fish, liver and meat.

Vitamin C

Believe it or not, I encounter scurvy in my practice today and it’s 2019. Patients and clients with bleeding, swollen and achy gums all of which resolve within a week after the initiation of vitamin C supplements.


But you don’t have to have scurvy to have functional vitamin C deficiency; an intake that is enough to prevent an overt clinical deficiency but not enough to allow one to function at one’s best.


The Role of Nutrients in Protecting Mitochondrial Function and Neurotransmitter Signalling: Implications for the Treatment of Depression, PTSD, and Suicidal Behaviours


One of the more common symptoms of obvious or functional vitamin C deficiency is depression. Like your white blood cells and adrenal glands,  your brain is a huge consumer of vitamin C. This vitamin helps to lower inflammation in the brain, lowering the risk for depression but also helps to prevent oxidation, or rusting, of your neurons.


However 20% percentage of the population can be functionally vitamin C deficient. Not only because they don’t get enough vitamin C from their diet but because they have a gene mutation that doesn’t allow them to absorb and metabolize it properly. This puts them at a 150% increased risk of vitamin C deficiency. Luckily this gene can be tested for using a simple saliva DNA test called Nutrigenonmix.


Good food sources include citrus, broccoli, kohlarbi, guava, papaya, lychee, pineapple, tomato, tomato juice, kiwi, bell peppers and strawberries.


Red grapefruit slices - 9 Nutrient Deficiencies That Can Cause Depression


Bottom line

In a nutshell, food feeds the brain. As an organ that accounts for 25% of our metabolic demands, the brain is in need of constant nourishment that can’t be met with a diet of crappy food.


Having optimal mental health cannot be realized if the underlying biology of mood regulation, the structure and function of the brain, isn’t addressed. This is where very building blocks of vitamins, minerals and essential fats come into play.


No amount of medication can make up for a lack of nutrients. Feeding your brain and an optimal sense of well-being is as close as your grocery store.


Doug Cook RDN is a Toronto based integrative and functional nutritionist and dietitian with a focus on digestive, gut, mental health.  Follow me on FacebookInstagram and Twitter.