9 Startling Nutrient Deficiencies That Can Cause Depression


10 Min Read

Deficiency of Omega-3 fats, Iodine, Zinc, Magnesium, Vitamin D, Selenium, Iron, B-complex and Vitamin C can trigger depression. The omega-3 fat DHA is critical for brain cell structure. Zinc improves digestive health promoting the release of serotonin and dopamine, magnesium helps produce vital enzymes and B-complex is required to maintain brain mass.

Working in Canada’s largest hospital for mental health and addiction, I absolutely appreciate the impact of lifestyle choices [diet/nutrition, stress reduction & leisure) on mental health including mood disorders like depression, seasonal effective disorder or SAD, anxiety and even bipolar disease.

As a nutrition educator, I routinely present on the topic of nutrition & brain health and food & mood. I review key nutrients that are absolutely vital for health brain; what we eat and drink directly affects the structure of the brain which, in turn, influences the brain’s function. This includes both the synthesis & function of neurotransmitters, as well as, the presence, or absence of inflammation.

The clients I work with are in recovery for drug [prescription & illicit] and alcohol addiction but essentially all of them are also dealing with mood disorders. It’s amazing to me how psychiatrists fail to appreciate the role of nutrition in mental health, including depression. It’s not only common sense but backed up by research that no amount of medication can make up for a crappy diet. The human body needs nutrients such as vitamins, minerals, essentially fats & antioxidants for vibrant health.

There is no biological or physiological need for Pristiq, Cymbalta, Wellbutrin, etc but there is for vitamin D, magnesium, iron and zinc for example.

It’s naive and unreasonable for anyone, doctor or patient, to think that one can be their best self, have optimal psychological and emotional health without addressing their underlying biology. Whether a person is using talk therapy, medication, or both to manage their mental health, there will be greater returns on investment, more bang for one’s buck if the physical health is addressed as well. Before anyone thinks I’m saying that medication don’t have a time and place in mental health is dead wrong. They do, but it’s important not to see the forest for the trees as they saying goes.

No amount of Paxil, Celexa, Lexapro or Viibryd will make up for an inadequate intake of iodine, B12, B3, folate or omega-3 fats or other nutrients.

Feeding Your Brain. Food and Mood

While there are dozens of neurotransmitters, many of which are produced in the gut as well as the brain, the three main ones that are talked about in mental health are serotonin, dopamine, and norepinepherine. The building blocks for these guys are amino acids derived from protein; a nutrient that most of use easily get in adequate amounts although they’re are exceptions [homeless, elderly, those with addiction]. The critical players in the synthesis and function of neurotransmitters however are vitamins & minerals. The analogy I like to use is a factory that needs a certain number of employees to show up for maximum output/production; if half call in sick, production suffers. Likewise for neurotransmitter production and function; we need optimal amounts of nutrients on a daily basis. If they are lacking in the diet, mood disorders, like depression, are more common and/or aggravated.

Optimize intake by improving diet and using targeted supplements, mood can improve and medication use reduced and sometimes eliminated according to loads of studies.

The star nutrient line-up includes

Omega-3 fats

The omega-3 fat DHA 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. Trans fat increase inflammation and this increases the risk for depression. The other main omega-3 fat EPA helps with neuron function, as well as, reduces inflammation which is why research supports the role of omega-3 fats in improving symptoms of depression [and other mood disorders]. Food sources are fatty fish, omega-3 fortified eggs and supplements.


Iodine can be thought of as the new vitamin D. 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. 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. 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. Good food sources include seaweed, cod, iodized salt. Other moderate food sources include milk, yogurt, and eggs. Good quality supplements should provide the RDA of 150 mcg as a foundation.


Zinc is tireless ally. It is involved in over 250 separate biochemical pathways, or reactions, that support just about every function needed for best health, not the least of which is a strong immune system and mental well-being. Zinc is critical for neurotransmitter production and function. It is also needed for healthy digestion and as I mentioned a strong immune system, most of which is found in the digestive tract. A healthy digestive tract = optimal mental health since 90% of serotonin and 50% of dopamine is produced in the small intestines. Best food sources include oysters, crab, beef, lamb, pork, dark meat, chicken, 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, needed for healthy bones & 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 and the reasons are numerous; see post here, and here. Magnesium is needed to activate the enzymes needed for serotonin, dopamine and norepinepherine production. Good food sources include nuts & seeds, dark green vegetables, whole grains, bran and dark chocolate. Supplements are typically needed to help people meet their minimum daily requirement on a consistent basis. Supplements will also help increase magnesium intake that moves people with depression into that functionally optimal range where depression can be improved versus just avoiding a magnesium deficiency.

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 vitamin, especially in Canada from mid-October till mid-April. The brain loves vitamin D and have loads of vitamin D receptors just waiting for their payload. I’ve written about vitamin D here, here, here, here and here. Vitamin D deficiency has not only been linked to depression, but anxiety, SAD, and dementia as well. 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. There is little natural food sources save oil/fatty fish like salmon, sardines, mackerel, herring and trout and eggs to a lesser extent.


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 needed to convert the inactive thyroid hormone T4 to the active form T3; this conversion primarily occurs in the liver. Selenium is needed to make the master antioxidant and detoxifying compound glutathione. Increasing glutathione has been shown to improve depression likely because glutathione reduces inflammation in the brain. Good food sources Brazil nuts, fish, 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 and it’s symptoms are similar to depression: fatigue, irritability, apathy, brain fog, lack of motivation & appetite. Having a broad range of symptoms can lead to a misdiagnosis and aggravate any existing legitimate depressive symptoms. Good food sources are beef, pork, lamb, dark meat chicken, eggs, liver, oysters and white beans. 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.


Typically includes about 11 B vitamins all of which are involved in neurotransmitter production and function. Some, like 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. 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. In order for dietary folate to be effective, 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] that metabolizes folate into 5-MTHF putting them at a 180% increased risk for folate deficiency. Luckily this gene mutation can be tested for using a simple saliva DNA test called Nutrigenonmix. B vitamins are found in whole grains, nuts & seeds, dark green vegetables and meat.

Vitamin C

Believe it or not, I encounter scurvy in my practice today and it’s 2014; 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. One of the more common symptoms of obvious or functional vitamin C deficiency is depression. Good food sources include citrus, kiwi, bell peppers and strawberries. 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; putting 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.

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

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

I am a Registered Dietitian & Integrative & Functional Nutritionist and former Certified Diabetes Educator with over 15 years of clinical nutrition experience. I practice a holistic and integrative approach providing science-based guidance on food and diet along with nutritional supplements where appropriate. My strength lies in my ability to explain complicated nutrition and scientific concepts in plain language which I then put into everyday practical dietary advice. I have a unique approach to nutrition counselling. I have the solid education & training of a dietitian but know that there are many points of views outside this model, and I incorporate them into my practice.

Doug Cook

I am a Registered Dietitian & Integrative & Functional Nutritionist and former Certified Diabetes Educator with over 15 years of clinical nutrition experience. I practice a holistic and integrative approach providing science-based guidance on food and diet along with nutritional supplements where appropriate. My strength lies in my ability to explain complicated nutrition and scientific concepts in plain language which I then put into everyday practical dietary advice. I have a unique approach to nutrition counselling. I have the solid education & training of a dietitian but know that there are many points of views outside this model, and I incorporate them into my practice.

Post a Comment
RebeccaBlackBowden 5pts

I love the information, but please have it edited... The errors are obnoxious. I hate sharing things online that are poorly written.

LouFlanaganCesario 5pts

My Dr told me that they have not proven vitamins really work.

Also they only stay in your system for a few hours.

kinkinyoursteel 5pts

@LouFlanaganCesario @LouFlanaganCesario  Oh wow. That's got to be false and, I would think, is a commonly pushed idea by those high up in the medical field/big pharma since it might affect the sale of prescription medications. If that were to be true, wouldn't the same vitamins we intake from actual food-that have been scientifically proven to aid our bodies-end up out of our bodies within a few hours as well? I now want to do more research on this claim. Also, if it were true that it has yet to be proven, how can they claim they only have a brief stay in one's system? I get that it's plausible, but it just doesn't add up.

Kristen Perez
Kristen Perez 5pts

My post partum depression was caused by nutritional deficiency.

Anastasia Sideris
Anastasia Sideris 5pts

Unfortunately there are a lot of people out there who will just take the prescribed medication given to them by their doctor, BUT, need to help/heal their gut before even those drugs will be of any value to them....Great tips here.

Emily S Palmer
Emily S Palmer 5pts

I recommend a good book: The Way Up from Down by Dr. Priscilla Slagle. Really, really helped me. Published in 1987 but right on the mark for me.

Tracie Bivins
Tracie Bivins 5pts

In the last 30 years, depression rates have gone through the roof, yet the treatments for it have remained the same. Einstein said that doing the same thing over and over again and expecting different results is the very definition of insanity. Therefore, you cannot expect rates of depression in the world to fall or the problem to be addressed properly until we radically change the treatment methods for it. This is why natural treatments such as the http://destroydepression.com/info.html system should get more exposure, because it tackles the root causes of depression through natural methods, rather than just treating the symptoms with medication.

Martha Macias
Martha Macias 5pts


Karen Antcliff-Vale
Karen Antcliff-Vale 5pts

If you live in the Great Lakes area, Unless you are taking these supplements, most likely you are deficient...especially vitamin. D, magnesium and iodine.

JaniceRichards 5pts

So nice to see good advice instead of the usual "take this pill" rubbish the media spew out. Depression is a DAILY struggle; it takes hard work to overcome it but there are natural treatments which are very effective. For anyone suffering from depression, I recommend the http://destroydepression.com/info.html system. Written by James Gordon, a former depression & PTSD sufferer, it teaches 7 natural steps which he used to cure his own depression and has helped thousands.

Karen Antcliff-Vale
Karen Antcliff-Vale 5pts

Many ways...including some lines of work, like welding, lead water pipes, leaded gasoline, mercury in you fillings and fish that you eat,cadmium from smoking cigarettes, and many others.my husband and I had heavy metal testing...he was off-the-chart in mercury and I was in lead, mercury and cadmium. We did chelation for a couple of years to get them down. Also, trace mineral deficiencies, such as zinc can cause a wide range of mental disorders. A book by William J. Walsh, Nutrient Power is very informative.

Girish Venkatesh
Girish Venkatesh 5pts

You'll be missed viru, really I cried when yo u announced your retirement,.

Bindu Kemmu
Bindu Kemmu 5pts

Very useful and true information thanks A but many times we have to take supplements pl tell how long it can be taken.

Rachel Wolfe
Rachel Wolfe 5pts

Great and helpful information, thank you for sharing \U0001f600

Parveen Kamal
Parveen Kamal 5pts

Thanks for sharing Jordank Addiep...\U0001f60a

Jordank Addiep
Jordank Addiep 5pts

I know how it feels to be depressed, at one point I tried killing myself twice in one week :( If you are stressed I would highly recommend everybody learn how to meditate because ever since I have started I have never been happier. I have improved my life drastically. I have an overall sense of peace with myself and the world. My stress levels have gone to an all time low and It even helps me with my anxiety and panic attacks.If you want to learn how to meditate I suggest you read this story.http://anxiousreview.com/learnmeditation/