Can Zinc Deficiency Contribute to Depression? Zinc, Copper and Mental Health

Can Zinc Deficiency Contribute to Depression? Zinc, Copper and Mental Health

Samantha Gilbert is a certified functional nutrition counselor and founder of Eat for Life, specializing in root-cause nutrition therapy for mental health, hormone imbalances, digestive disorders, and chronic illness.

“Nearly all disease can be traced to a nutritional deficiency” stated Linus Pauling, two-time Nobel Prize winner.

But conventional medicine will have you believe all body systems are separate and that popping a pill will eliminate depression and its many side-effects, most notably, weight gain.

We now know that depression is a term, not a condition and that there are actually five distinct types of depression , each with different underlying nutrient imbalances as the root cause.

And I should know, I spent over 25 years trying to figure this out for myself.

Even if you don’t struggle with depression, but can’t seem to lose weight, you should pay close attention to this important mineral.

It’s called zinc.

Yes, the mineral you’re probably familiar with as a treatment for the common cold also plays important roles in growth and development, the immune response, neurological function, and reproduction.

Low zinc status has repeatedly been associated with depression, but that does not mean zinc deficiency is the cause of every case of depression. Depression is multifactorial, and nutrition is only one part of the picture. What makes zinc particularly interesting is its role in hundreds of enzymes and cellular processes involved in immune function, cell signaling, growth, repair, and normal nervous-system function. Zinc also interacts closely with copper, which means that looking at either mineral in isolation can sometimes provide an incomplete picture.

Recent research continues to investigate how zinc deficiency, copper levels, and mineral imbalance may relate to depression and anxiety. The sections below explain what current evidence supports, what remains uncertain, and why testing and individualized interpretation matter.

Why Zinc Matters

Zinc is essential to all forms of life and is a component of more than 300 enzymes. It enhances resistance to stress, maintains intellectual function, memory, and mood levels. Zinc also enhances gene expression of cysteine-rich proteins called metallothionines.

Current NIH guidance describes zinc as necessary for the catalytic activity of hundreds of enzymes and for immune function, DNA and protein synthesis, cell signaling, wound healing, growth, development, and normal sensory function. The body contains about 1.5 grams of zinc in women and 2.5 grams in men, with much of it stored in skeletal muscle and bone.

How Common Is Low Zinc Status?

Zinc inadequacy is common enough to deserve attention, even though it should never be assumed from symptoms alone. According to the National Institutes of Health, about 15% of U.S. adults age 19 and older have zinc intakes below the Estimated Average Requirement.

An analysis of U.S. NHANES data also found serum zinc concentrations below age- and sex-specific sufficiency cutoffs in 8.6% of males age 10 and older, 8.2% of females, and 3.8% of children younger than 10.

These figures do not mean low zinc explains depression in those populations. They show that inadequate zinc intake or status is common enough to consider when a person’s diet, symptoms, or medical history suggests a possible deficiency.

Zinc Deficiency and Depression: What Does the Research Show?

The relationship between zinc deficiency and depression has been studied for decades. A 2025 systematic review and meta-analysis evaluated 16 observational studies comparing serum zinc, copper, and iron levels in people with major depressive disorder and healthy controls.

The researchers found significantly lower serum zinc in people with major depressive disorder. The standardized mean difference for zinc was -0.62, and the association remained significant after adjustment for publication bias. Serum iron was also lower. Copper was higher in the initial pooled analysis, although the copper result was less certain after publication-bias adjustment.

Earlier evidence points in the same direction. A 2013 meta-analysis of 17 studies involving 1,643 people with depression and 804 controls found peripheral blood zinc concentrations were about 1.85 µmol/L lower in the depression groups.

Depression itself can affect appetite, diet quality, inflammation, weight, and other factors that may influence zinc status, so the relationship may work in more than one direction.

How Might Zinc Be Connected to Mood?

Researchers are studying several biological pathways that may help explain the relationship between zinc status and mental health.

Neurotransmitter and Synaptic Signaling

Zinc participates in signaling within the nervous system and interacts with glutamate and other pathways involved in how neurons communicate.

Neuroplasticity

Zinc has been studied in relation to brain-derived neurotrophic factor (BDNF) and other processes involved in neuronal growth, adaptation, and plasticity.

Oxidative Stress

Zinc contributes to antioxidant defense systems that help protect cells from oxidative damage.

Immune and Inflammatory Signaling

Zinc plays an important role in immune regulation. Inflammation is also one of many biological pathways being investigated in depression. These mechanisms are biologically plausible, but they should not be interpreted to mean that correcting zinc alone will resolve depression.

When metallothionine production is disabled due to oxidative stress and toxic heavy metals, the body is open to all kinds of assaults from pathogens and viruses; as well as an inability to properly absorb nutrients from food.

Metallothionines have powerful antioxidant properties and work in tandem with glutathione and selenium to bind to toxic heavy metals and transport them out of the body. Without this important function, heavy metals, most notably mercury and copper, pass through the intestinal and blood/brain barriers leading to depression, chronic fatigue, and weight gain.

Metallothioneins are small, cysteine-rich proteins involved in metal binding, antioxidant defense, and the regulation of minerals including zinc and copper. This is one reason zinc and copper should not always be considered independently. The body tightly regulates both minerals, and changing one through supplementation can affect the other.

With copper high, zinc can become imbalanced. Copper and zinc work in tandem with each other to control the overgrowth of fungal, yeast, and parasitic infections. Without the proper ratio, these types of infections can become chronic and difficult to eliminate.

Zinc and Copper Balance

Zinc and copper interact during absorption and metabolism. However, low zinc does not automatically mean high copper, and high copper does not automatically mean zinc deficiency.

A person’s copper-zinc pattern can be affected by diet, supplements, absorption, inflammation, gastrointestinal health, pregnancy, estrogen status, liver function, and other medical conditions. This is why zinc-copper imbalance symptoms cannot be diagnosed from symptoms alone. Laboratory values and the broader clinical picture need to be considered together.

Copper and Depression: What Does Current Research Show?

Copper is also essential for normal neurological function, energy production, iron metabolism, antioxidant enzymes, and pathways involved in neurotransmitter metabolism. Research examining copper and depression has produced interesting but sometimes conflicting findings.

A 2025 systematic review and meta-analysis of 24 studies involving 8,617 participants found serum copper levels were, on average, higher in people with major depressive disorder. However, there was very high variation between studies. A separate 2025 meta-analysis also found higher copper in its initial pooled analysis, but described the copper evidence as less conclusive after evaluating publication bias.

Dr. William Walsh’s research remains the gold standard today.

What About Copper Deficiency and Depression?

Some people search specifically for whether copper deficiency can cause depression or anxiety. Copper is required for normal nervous-system function and several copper-dependent enzymes, and severe copper deficiency can produce neurological and hematological problems.

However, current depression research does not establish copper deficiency as a common direct cause of depression. Both too little and too much copper can be clinically important in specific situations, which is why symptoms alone cannot tell you which pattern is present.

In the initial stages of working with a client, I look at three main areas: malnourishment, food toxins, and pathogens.

All three significantly affect the body’s ability to shed fat and be happy because they all can lead to deficiencies in zinc. This is why PCOS nutrition support is so effective it focuses on repairing the gut terrain so you can finally absorb the minerals required for both hormonal and mental well-being.

From a functional nutrition perspective, nutrient intake, digestion, absorption, supplement use, inflammation, hormonal changes, and relevant laboratory findings can all be considered when evaluating a possible deficiency. Nutrient status is one part of the larger health picture, and a genuine deficiency should be identified rather than assumed from symptoms alone.

In all cases of disordered eating from anorexia to bulimia and in between, zinc status should always be assessed.

In people with disordered eating, nutritional status can be compromised because restrictive intake, vomiting, gastrointestinal issues, and other behaviors may reduce nutrient intake or increase losses. Zinc can be one of several nutrients worth assessing as part of a broader evaluation, but zinc deficiency should not be assumed in every person with an eating disorder.

This takes me back to my vegan days. I had no desire for meat and swore I would never eat it again for the rest of my life. Little did I know at the time my distaste for meat was the result of severe nutrient deficiencies, something I was able to correct through targeted nutrition therapy for depression and strategic zinc supplementation.

Plant-based diets can provide zinc, but zinc from legumes, whole grains, nuts, and seeds generally has lower bioavailability because phytates can reduce absorption. This does not mean a vegan diet automatically causes zinc deficiency, but zinc intake and absorption deserve closer attention in people following highly plant-based or restrictive diets.

What Can Cause Zinc Deficiency?

1. Hereditary factors (I see this often in families)
2. Low dietary zinc intake.
3. Reduced absorption from gastrointestinal conditions such as celiac disease, inflammatory bowel disease, chronic diarrhea, or other malabsorptive disorders.
4. Restrictive eating or chronically low calorie intake.
5. Higher requirements during pregnancy and lactation.
6. Chronic alcohol use and certain illnesses that affect intake, absorption, metabolism, or losses.
7. Medication-related effects or interactions in some people.

How Is Zinc Deficiency Tested?

Serum or plasma zinc is commonly used to assess zinc status. The NIH notes that concentrations in healthy people typically range from 80 to 120 mcg/dL. Serum zinc below about 70 mcg/dL in women and 74 mcg/dL in men can indicate inadequate zinc status.

In my practice, I do things differently. I review markers through a functional, biochemical lens so I can get a clear and accurate picture. If there’s concern about copper-zinc balance, copper and ceruloplasmin may also be considered depending on the situation. No single mineral test should be used on its own to explain depression.

Can Too Much Zinc Cause Depression?

There is insufficient evidence to say that excessive zinc directly causes depression. However, chronically high zinc intake can cause other health problems, particularly copper deficiency.

According to the NIH, the adult Tolerable Upper Intake Level for zinc is 40 mg per day from food and supplements for healthy adults. They also note that taking 50 mg or more per day for several weeks can interfere with copper absorption, reduce immune function, and lower HDL cholesterol. Excess zinc can also cause nausea, vomiting, headaches, gastric distress, and loss of appetite.

However, it’s important to keep in mind that these reference ranges don’t take biochemical individuality into account, nor the clinical research and application showing that 90% of people who struggle with depression and anxiety are depleted in zinc and require therapeutic doses based on lab testing and professional guidance (see The Walsh Research Institute https://www.walshinstitute.org/published-research.html).

Taking high-dose zinc indefinitely because of depression, anxiety, or a presumed copper imbalance is not a safe strategy. Doing so without professional guidance and appropriate lab testing is not recommended.

How Much Zinc Do Adults Need?

Group	Recommended Zinc Intake
Adult men	11 mg/day
Adult women	8 mg/day
Pregnancy	11 mg/day
Lactation	12 mg/day

Is Zinc an Antidepressant?

Zinc is an essential nutrient for the brain to function optimally but it’s not an antidepressant medication.

A 2020 meta-analysis found that zinc supplementation was associated with lower depressive symptom scores in some randomized trials, while cohort data linked higher zinc intake with a lower risk of depression. The authors emphasized that more trials were needed to clarify who benefits, appropriate dosing, and whether zinc is most useful alone or alongside other treatment.

Correcting a documented deficiency may be appropriate, but that is different from assuming zinc supplements will treat depression in everyone. If you take psychiatric medication, do not stop or change it based on nutritional information without discussing the decision with the prescribing clinician.

Is Zinc the Only Mineral Associated With Depression?

No. The 2025 meta-analysis evaluating trace minerals and major depressive disorder found lower average serum zinc and iron in people with MDD, while copper was higher in the initial pooled analysis. These findings do not mean depression is simply a mineral-deficiency condition. They support the broader idea that nutritional status can interact with neurological, immune, endocrine, inflammatory, and metabolic pathways relevant to mental health.

Food First, Supplement Second

When zinc intake is inadequate, food is usually the safest place to begin unless a clinician has identified a reason supplementation is necessary.

Supplementation should be individualized rather than based on symptoms alone.

The truth is that we all have nutrient deficiencies and as we get older, we become even more susceptible. Some can be corrected with diet alone, while others require diet and supplementation to overcome.

Nutrient inadequacies can become more likely depending on age, diet, digestive health, medications, illness, and lifestyle. Some can be corrected by improving dietary intake, while others may require targeted supplementation after the underlying cause has been identified.

When Depression Needs More Than Nutritional Support

Nutrition can support overall health, but depression should never automatically be attributed to zinc, copper, or another nutrient. Depression can have many contributing factors and may require care from a physician, psychiatrist, psychologist, therapist, or other qualified mental-health professional.

Seek appropriate professional care if symptoms are persistent, worsening, significantly affecting daily life, or associated with thoughts of self-harm.

Frequently Asked Questions

Can zinc deficiency cause depression?

Studies consistently show an association between lower zinc levels and depression, but current research does not prove that zinc deficiency is the cause of every case of depression. Depression is multifactorial.

Can zinc deficiency cause anxiety?

Low zinc status has been investigated in relation to anxiety and stress regulation (see Dr. Walsh’s research https://www.walshinstitute.org/published-research.html). A biological relationship has been established, though it is true that zinc isn’t the cause of all anxiety.

Can too much zinc cause depression?

There is not strong evidence that excessive zinc directly causes depression. However, chronically high zinc intake can interfere with copper absorption and lead to copper deficiency and other health problems.

Can copper deficiency cause depression or anxiety?

Copper deficiency can affect the nervous system, but current research does not establish low copper as a common direct cause of depression or anxiety. Both copper deficiency and excess can have health consequences.

What are the symptoms of a zinc-copper imbalance?

There is no unique symptom pattern that can diagnose a zinc-copper imbalance. Symptoms overlap with many medical and psychological conditions, so laboratory testing and clinical context are important.

How do I know whether I am zinc deficient?

Plasma zinc testing is a helpful tool to assess zinc status, but results need to be interpreted with other diagnostic testing, diet, symptoms, inflammation, medications, and other health factors.

Does zinc work like an antidepressant?

No. Zinc is an essential nutrient, not an antidepressant medication. Research suggests that correcting inadequate zinc or using zinc supplementation in selected patients may influence depressive symptoms, but it should not replace appropriate mental-health treatment.

Should zinc and copper be tested together?

It’s best to test them together because both minerals play important biological roles, and each person metabolizes them differently. Other factors such as methylation status and pyrrole levels are also important within an individual’s health history and clinical context.

If you know of someone who struggles with their weight and/or depression, please share this post. If you struggle, please share your experience in the comments below. It is through sharing your story that we create community, eliminate guilt and shame, and bring about healing.

References

1.  National Institutes of Health, Office of Dietary Supplements. Zinc: Fact Sheet for Health Professionals.

2.    Davarinejad O, Nasseri Z, Mansouri B. Association between serum levels of essential elements (copper, zinc, and iron) and major depressive disorder: a systematic review and meta-analysis. Review of Environmental Health. 2025.

3.    Swardfager W, et al. Zinc in depression: a meta-analysis. Biological Psychiatry. 2013.

4.    Yosaee S, et al. Zinc in depression: From development to treatment: A comparative/dose response meta-analysis of observational studies and randomized controlled trials.

5.    Squitti R, et al. Copper Dysregulation in Major Depression: A Systematic Review and Meta-Analytic Evidence for a Putative Trait Marker. International Journal of Molecular Sciences. 2025.

6.    National Institutes of Health, Office of Dietary Supplements. Copper: Fact Sheet for Health Professionals.