10 Plant-Based Nutritional Deficiencies That Impact Mental Health — And How to Fix Them
— By Brian Mears, DNAP, APRN, CRNA, PMHNP
Mental Health Starts with Nutrition
At Alleviant, we treat the whole person — brain, body, and spirit. But without proper nutrition, even the best therapy or medication may fall short. The brain requires precise nutrients to regulate mood, improve cognition, and manage stress.
Unfortunately, many people today are unknowingly deficient in nutrients that directly affect mental health — even those eating what they believe is a healthy diet.
The good news? With the right plant-based foods and supplements, you can restore what your brain has been missing and begin to feel significantly better.
10 Critical Nutrients for Brain Health (Plant-Based Edition)
Each section below includes:
A description of the nutrient’s role in mental health
A per-serving nutrient table of top plant-based foods
A vegan-friendly supplement recommendation
1. Vitamin B12 — The Brain’s Spark Plug
Why it matters: B12 supports nerve insulation (myelin), neurotransmitter synthesis, and energy regulation. Deficiency can lead to fatigue, brain fog, depression, and cognitive decline.¹
Top Plant-Based Sources:
| Food Source | Amount |
| Fortified nutritional yeast (1 tbsp) | 24 mcg |
| Fortified soy milk (1 cup) | 3 mcg |
| Fortified cereal (1 serving) | 6 mcg |
Plant-Based Supplement: Methylcobalamin or cyanocobalamin B12 (sublingual or capsule)
2. Magnesium — The Anti-Anxiety Mineral
Why it matters: Magnesium helps regulate neurotransmitters, reduce brain inflammation, and lower anxiety.² Stress rapidly depletes magnesium stores.
Top Plant-Based Sources:
| Food Source | Amount |
| Pumpkin seeds (1 oz) | 168 mg |
| Spinach, cooked (1 cup) | 157 mg |
| Black beans (1 cup) | 120 mg |
Plant-Based Supplement: Magnesium glycinate or citrate (vegan formulation)
3. Omega-3 (ALA) — The Brain’s Structural Fat
Why it matters: Omega-3s reduce inflammation, support neural integrity, and improve symptoms of depression, anxiety, and ADHD.³ Most plant-based diets are low in EPA/DHA.
Top Plant-Based Sources:
| Food Source | Amount |
| Chia seeds (1 oz) | 5060 mg ALA |
| Flaxseeds (1 tbsp) | 2350 mg ALA |
| Walnuts (1 oz) | 2540 mg ALA |
Plant-Based Supplement: Algal oil (contains EPA & DHA from algae)
4. Vitamin D — The Sunshine Regulator
Why it matters: Vitamin D modulates serotonin, reduces inflammation, and improves mood.⁴ Deficiency is common in those with limited sun exposure.
Top Plant-Based Sources:
| Food Source | Amount |
| UV-exposed mushrooms (1 cup) | 400 IU |
| Fortified soy milk (1 cup) | 100 IU |
| Fortified orange juice (1 cup) | 137 IU |
Plant-Based Supplement: Vegan D3 (lichen-based) or D2 (ergocalciferol)
5. Zinc — The Mood Stabilizer
Why it matters: Zinc modulates GABA and glutamate activity, reduces inflammation, and supports neuroplasticity.⁵ Low zinc is linked to depression and emotional instability.
Top Plant-Based Sources:
| Food Source | Amount |
| Pumpkin seeds (1 oz) | 2.2 mg |
| Chickpeas (1 cup) | 2.5 mg |
| Cashews (1 oz) | 1.6 mg |
Plant-Based Supplement: Zinc gluconate or picolinate (vegan capsules)
6. Iron — Oxygen for the Brain
Why it matters: Iron deficiency can impair attention, cause fatigue, and mimic symptoms of anxiety or ADHD.⁶ Women and vegans are especially at risk.
Top Plant-Based Sources:
| Food Source | Amount |
| Lentils (1 cup cooked) | 6.6 mg |
| Tofu (½ cup) | 3.4 mg |
| Spinach, cooked (1 cup) | 6.4 mg |
Plant-Based Supplement: Ferrous bisglycinate or iron-rich herbs (with vitamin C for absorption)
7. Choline — The Memory Molecule
Why it matters: Choline supports acetylcholine production, memory, and cognitive flexibility.⁷ It’s often low in plant-based diets.
Top Plant-Based Sources:
| Food Source | Amount |
| Soybeans, cooked (1 cup) | 107 mg |
| Quinoa, cooked (1 cup) | 43 mg |
| Broccoli, cooked (1 cup) | 63 mg |
Plant-Based Supplement: Alpha-GPC or Citicoline (vegan formulation)
8. Vitamin B6 — The Neurotransmitter Catalyst
Why it matters: B6 is critical for serotonin, dopamine, and GABA synthesis. Deficiency may cause mood swings, anxiety, and fatigue.⁸
Top Plant-Based Sources:
| Food Source | Amount |
| Banana (1 medium) | 0.4 mg |
| Potato (1 medium, baked) | 0.6 mg |
| Chickpeas (1 cup, cooked) | 1.1 mg |
Plant-Based Supplement: Pyridoxal-5-phosphate (P5P)
9. Selenium — The Brain’s Detox Ally
Why it matters: Selenium supports thyroid and antioxidant function. Low levels have been associated with increased anxiety and depression.⁹
Top Plant-Based Sources:
| Food Source | Amount |
| Brazil nuts (1 nut) | 96 mcg |
| Sunflower seeds (1 oz) | 19 mcg |
| Brown rice (1 cup) | 19 mcg |
Plant-Based Supplement: Selenomethionine (vegan capsule)
10. Iodine — The Mental Clarity Mineral
Why it matters: Iodine supports thyroid hormones, which regulate mood, energy, and cognition.¹⁰ Vegans are at high risk of deficiency.
Top Plant-Based Sources:
| Food Source | Amount |
| Seaweed, dried (1 g) | 16–2980 mcg |
| Iodized salt (¼ tsp) | 76 mcg |
| Cranberries (1 cup) | 400 mcg |
Plant-Based Supplement: Kelp-based iodine or potassium iodide drops
What We Do at Alleviant
We perform spectral EEG (sEEG) scans to visualize brain function — helping us determine whether nutritional and treatment plans are working.
Our certified health coaches create custom nutrition and supplement plans.
We track clinical progress and re-evaluate over time — all at no extra cost for most patients.
We believe nutrition is foundational, and we make it easy to understand and apply.
Wondering if you’re missing key nutrients affecting your mental health?
Let us help you uncover and correct the root causes.
References
1. Reynolds, E. (2006). Vitamin B12, folic acid, and the nervous system. The Lancet Neurology, 5(11), 949–960.
2. Boyle, N. B., et al. (2017). The effects of magnesium supplementation on subjective anxiety and stress. Nutrients, 9(5), 429.
3. Grosso, G., et al. (2014). Role of omega-3 fatty acids in the treatment of depressive disorders: A comprehensive meta-analysis. PLoS One, 9(5), e96905.
4. Anglin, R. E. S., et al. (2013). Vitamin D deficiency and depression in adults: A systematic review and meta-analysis. British Journal of Psychiatry, 202(2), 100–107.
5. Swardfager, W., et al. (2013). Zinc in depression: A meta-analysis. Biological Psychiatry, 74(12), 872–878.
6. Beard, J. L. (2003). Iron deficiency alters brain development and functioning. The Journal of Nutrition, 133(5), 1468S–1472S.
7. Zeisel, S. H. (2006). Choline: Critical role during fetal development and dietary requirements in adults. Annual Review of Nutrition, 26, 229–250.
8. Kennedy, D. O. (2016). B Vitamins and the brain: mechanisms, dose and efficacy—a review. Nutrients, 8(2), 68.
9. Rayman, M. P. (2012). Selenium and human health. The Lancet, 379(9822), 1256–1268.
10. Zimmermann, M. B. (2009). Iodine deficiency in industrialized countries. Clinical Endocrinology, 71(3), 319–328.