Can nutrient deficiencies lead to anxiety or depression in teens?
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It’s not uncommon for teens to struggle with anxiety, low mood, fatigue, or changes in motivation. These concerns are increasingly common, and there are many important pieces to supporting teen mental health including therapy, relationships, sleep, and stress management.
One piece that is often overlooked, however, is nutrition.
At Montana Whole Health, we specialize in holistic mental health care for children and teens. Our approach is to look at how the body is functioning as a whole, including whether it has the nutrients it needs to support healthy brain chemistry.
How nutrients affect mood
You’ve probably heard of neurotransmitters like serotonin and dopamine. Neurotransmitters are chemical messengers that the brain relies on to regulate mood, focus, motivation, and sleep.
What many people don’t realize is that the body needs specific nutrients to produce and regulate these neurotransmitters. Let’s dive into a bit of biochemistry (don’t worry we won’t geek out too much!).
Serotonin: helps support a sense of calm, emotional stability, and sleep
Made from the amino acid tryptophan, serotonin requires:
- Tryptophan – the building block (protein-rich foods like turkey, eggs, dairy, legumes)
- Vitamin B6 (Pyridoxine) – converts tryptophan into serotonin
- Vitamin B3 (Niacin) – supports tryptophan metabolism (breakdown and recycling)
- Folate (B9) – aids neurotransmitter production through methylation processes
- Vitamin D – helps regulate serotonin production and receptor function
- Magnesium & Zinc – support serotonin receptor signaling
Dopamine: plays a key role in motivation, focus, and reward
Made from the amino acid tyrosine (or phenylalanine), dopamine requires:
- Tyrosine / Phenylalanine – dietary precursors (meat, eggs, dairy, legumes, nuts)
- Vitamin B6 – converts L-DOPA into dopamine
- Folate (B9) Vitamin B12 – support dopamine metabolism through methylation processes
- Iron & Copper – cofactors for dopamine production
- Magnesium & Zinc – influence dopamine receptor function
Low levels of any of these nutrients can make it harder for the brain to produce or regulate neurotransmitters, which may be associated with fatigue, low mood, anxiety, irritability, and difficulty focusing.
Even when a teen is doing everything “right,” or taking pharmaceutical medications, low levels of key nutrients can make it harder for the brain to maintain balance.
Key missing nutrients that support teen mental health
Iron
Iron is essential for oxygen delivery to the brain and plays a role in dopamine production.
Low iron levels may be associated with:
- Fatigue or low energy
- Brain fog
- Low motivation
- Irritability
This is especially common in teens who are menstruating or who have limited dietary intake of iron-rich foods. Research shows that approximately 38.6% of females aged 12-21 years in the US have iron deficiency.
Important note: Iron deficiency can affect the brain even before anemia develops. Recent studies show that iron deficiency without anemia is associated with reduced brain iron content in areas important for mood and motivation, which correlates with worse psychiatric symptoms and cognitive function in adolescents.
Vitamin D
Vitamin D plays an important role in mood regulation and brain signaling.
Low levels may be associated with:
- Low mood
- Fatigue
- Getting sick more frequently
Deficiency is very common, particularly in northern climates where sun exposure is limited for much of the year (welcome to Montana!). Research has found that higher vitamin D levels are linked with lower risk of developing depression in early adolescents.
B Vitamins (B6, B12, Folate)
B vitamins are key cofactors in the production of serotonin and dopamine through their roles in methylation and neurotransmitter metabolism.
Low levels may be associated with:
- Anxiety or low mood
- Low energy
- Difficulty concentrating
Lower vitamin B12 levels have been correlated with higher risk of severe anxiety and depressive symptoms in adolescents.
Magnesium
Magnesium helps regulate the nervous system and supports a more relaxed, balanced state.
Low levels may show up as:
- Anxiety or irritability
- Restlessness
- Difficulty falling or staying asleep
Research in adults has found associations between higher magnesium intake and reduced anxiety, as well as improved sleep quality. One study in adolescents found that higher magnesium intake was associated with reduced externalizing behaviors (aggression, defiance, hyperactivity).
Signs your teen may have a nutrient deficiency
Not every teen with these symptoms has a nutrient deficiency—but it can be a helpful place to explore, especially when symptoms are ongoing.
Some common signs include:
- Persistent fatigue
- Low motivation or loss of interest in activities
- Anxiety or irritability
- Difficulty focusing
- Poor or disrupted sleep
Our approach to mental health at Montana Whole Health
Supporting teen mental health is never about just one thing—and nutrition is only one piece of the picture.
At Montana Whole Health, we take a comprehensive approach that may include:
- Reviewing diet, sleep, and daily habits
- Identifying potential nutrient gaps
- Ordering labs to assess nutrient status (such as iron, vitamin D, or B vitamin levels)
- Creating a personalized plan that may include nutrition and, when needed, supplementation
- Provide nutrition education to your teen in a way that feels supportive and sustainable
The goal is to support the body in a way that complements other important mental health care, such as counseling and, when appropriate, medication.
A final note
Mental health is complex, and there is rarely a single cause for how someone is feeling. But making sure the body has the nutrients it needs to function well can be an important (and often overlooked!) place to start.
References
- Folate, Vitamin B12, and Neuropsychiatric Disorders. Bottiglieri T. Nutrition Reviews. 1996;54(12):382-90. doi:10.1111/j.1753-4887.1996.tb03851.x.
- Adolescent-Onset and Adult-Onset Vitamin-Responsive Neurogenetic Diseases: A Review. Mandia D, Shor N, Benoist JF, Nadjar Y. JAMA Neurology. 2021;78(4):483-490. doi:10.1001/jamaneurol.2020.4911.
- Vitamin D and Depressive Symptoms in an Early Adolescent Cohort. Wang G, Yuan M, Chang J, et al. Psychological Medicine. 2023;53(12):5852-5860. doi:10.1017/S0033291722003117.
- Potential Role of Vitamin D for the Management of Depression and Anxiety. Casseb GAS, Kaster MP, Rodrigues ALS. CNS Drugs. 2019;33(7):619-637. doi:10.1007/s40263-019-00640-4.
- Psychiatric and Cognitive Outcomes of Iron Supplementation in Non-Anemic Children, Adolescents, and Menstruating Adults: A Meta-Analysis and Systematic Review. Fiani D, Chahine S, Zaboube M, et al. Neuroscience and Biobehavioral Reviews. 2025;:106372. doi:10.1016/j.neubiorev.2025.106372.
- Iron Deficiency Without Anemia and Reduced Basal Ganglia Iron Content in Youths. Fiani D, Kim JW, Hu M, et al. JAMA Network Open. 2025;8(6):e2516687. doi:10.1001/jamanetworkopen.2025.16687.
- Iron Deficiency and Internalizing Symptom Severity in Unmedicated Adolescents: A Pilot Study. Abbas M, Gandy K, Salas R, Devaraj S, Calarge CA. Psychological Medicine. 2023;53(6):2274-2284. doi:10.1017/S0033291721004098.
- Does Inflammation Explain the Association Between Vitamin D and Depression? Results of a Cross-Sectional Study in Children and Adolescents. Schlarbaum L, Jankovic N, Bühlmeier J, et al. The British Journal of Nutrition. 2026;:1-37. doi:10.1017/S0007114526106928.
- Association of Low Vitamin B12 Levels With Depressive and Schizophrenia Spectrum Disorders in Child and Adolescent Psychiatric Inpatients. Anmella G, Varela E, Prades N, et al. European Child & Adolescent Psychiatry. 2025;:10.1007/s00787-025-02662-4. doi:10.1007/s00787-025-02662-4.
- Vitamin B12, Folate, Homocysteine, Inflammatory Mediators (Interleukin-6, Tumor Necrosis Factor-Α and C-Reactive Protein) Levels in Adolescents With Anxiety or Depressive Symptoms. Tan Y, Zhou L, Huang J, et al. Neuropsychiatric Disease and Treatment. 2023;19:785-800. doi:10.2147/NDT.S399378.
- Magnesium Disorders. Touyz RM, de Baaij JHF, Hoenderop JGJ. The New England Journal of Medicine. 2024;390(21):1998-2009. doi:10.1056/NEJMra1510603.
- Association of Magnesium Intake With Sleep Duration and Sleep Quality: Findings From the CARDIA Study. Zhang Y, Chen C, Lu L, et al. Sleep. 2022;45(4):zsab276. doi:10.1093/sleep/zsab276.
- The Association Between Dietary Intake of Magnesium and Psychiatric Disorders Among Iranian Adults: A Cross-Sectional Study. Anjom-Shoae J, Sadeghi O, Hassanzadeh Keshteli A, et al. The British Journal of Nutrition. 2018;120(6):693-702. doi:10.1017/S0007114518001782.
- Low Dietary Intake of Magnesium Is Associated With Increased Externalising Behaviours in Adolescents. Black LJ, Allen KL, Jacoby P, et al. Public Health Nutrition. 2015;18(10):1824-30. doi:10.1017/S1368980014002432.