10 Nutrients Proven to Boost Your Mood and Energy

Chronic low-level nutrient deficiency can affect mood, motivation, and energy in ways that don't feel like a deficiency — they feel like being tired and flat "lately." Ten nutrients where the evidence is strong enough to take seriously, with an honest account of what each does and does not do.

One rule first: deficiency correction is not the same as supplementation benefit. Correcting a genuine deficiency often produces a dramatic lift. Taking extra of a nutrient you're not missing generally does nothing. These two realities are routinely conflated in supplement marketing, and separating them saves money and sets realistic expectations.

1. Vitamin D

Deficiency correlates with depressive symptoms — and this correlation is real enough to take seriously. What the supplementation research actually shows is more qualified. A 2024 dose-response meta-analysis in Psychological Medicine (Cambridge University Press) pooled 31 RCTs covering 24,189 participants and found vitamin D3 supplementation moderately reduced depressive symptoms (SMD −0.32 per 1,000 IU/day, moderate-certainty evidence). Effects were more pronounced in people with baseline depression (SMD −0.57). No significant effect on anxiety was detected, and benefits were non-significant in trials lasting over 52 weeks.

Practical guidance: test your 25(OH)D level before supplementing. A level below 50 nmol/L (20 ng/mL) is generally considered deficient. Where supplementation is warranted, 1,000–2,000 IU daily is a reasonable starting dose. More is not automatically better — excess vitamin D accumulates and is toxic.

Food sources: fatty fish (salmon, sardines, mackerel), egg yolks, fortified dairy and plant milks.

2. Vitamin B12 — the deficiency-only rule

B12 is essential for nervous-system function and red blood cell formation. Genuine deficiency causes fatigue, weakness, and — if untreated — irreversible neurological damage. These consequences are serious. But a 2024 meta-analysis of 9 RCTs published in Cureus found no significant effect of B12 supplementation on cognitive memory (SMD −0.03, p=0.18) or depressive symptoms (SMD −0.01, p=0.71) in older adults without established deficiency. B12 corrects deficiency-related symptoms; it does nothing for people who are not deficient.

Who is at genuine risk: people on entirely plant-based diets, older adults (gastric acid decline impairs absorption), and people on metformin or long-term proton-pump inhibitors. If plant-based, supplementation is medically appropriate — not optional.

Food sources: meat, fish, eggs, dairy, and B12-fortified plant milks and cereals.

3. The B-vitamin-for-mood overclaim

This section stands on its own because the marketing narrative around B vitamins and mood deserves direct correction. A 2024 Mendelian randomisation study in Nutrients — using 50 genetic variants in a large population sample — found no causal association between genetically determined folate, vitamin B6, or homocysteine levels and rates of depression, anxiety, bipolar disorder, OCD, or schizophrenia. More striking: genetically higher B12 was associated with higher risk of anxiety (OR 1.34) and bipolar disorder (OR 1.85), suggesting a U-shaped relationship where both deficiency and excess may carry risk.

Folate (B9) has an established role in the methylation pathway, and observational studies associate deficiency with mood disorders — but the Mendelian randomisation result specifically tests causality, and it didn't hold. Taking extra B vitamins when you're not deficient is unlikely to improve your mood.

Food sources for folate: dark leafy greens, legumes, citrus, asparagus.

4. Iron

Iron deficiency is one of the most underdiagnosed correctable causes of fatigue and low mood in adults, particularly in women of reproductive age and adolescents. The diagnostic gap exists partly because clinicians often test haemoglobin (anaemia) rather than ferritin (iron stores) — you can be iron-depleted, with measurable effects on energy and cognitive function, while haemoglobin reads as normal. Iron is essential for mitochondrial energy generation: reduced availability directly impairs cellular energy production, which explains why pre-anaemic deficiency produces the same fatigue profile as frank anaemia.

Practical guidance: ask specifically for a ferritin test if fatigue is your complaint. A ferritin below 30 µg/L is commonly treated even without anaemia. Don't supplement iron without testing — excess iron is harmful, and deficiency fatigue is indistinguishable from other causes without a blood test.

Food sources: red meat and organ meats (highest bioavailability); lentils, spinach, tofu, fortified cereals (lower bioavailability — pair with vitamin C to improve absorption). Tea and coffee reduce non-haem iron absorption; drink them between meals if iron deficiency is a concern.

5. Omega-3 (EPA + DHA)

Omega-3 DHA is a structural component of neuronal membranes; EPA modulates neuroinflammation. The supplementation evidence shows a real but modest, context-dependent benefit. Pooled analyses across multiple systematic reviews (26,881 participants combined) have found significant but small cognitive improvement (effect size 0.16; 95% CI 0.01–0.32) in non-demented adults and those with mild cognitive impairment — with no dose-response relationship, suggesting a threshold rather than a linear effect. A 2022 systematic review in Cureus found the strongest benefits in elderly and cognitively impaired populations; supplementation showed no meaningful impact in cognitively healthy adults. For mood, EPA specifically has the strongest signal for reducing depressive symptoms in people with a clinical diagnosis of depression.

Food sources: fatty fish (salmon, sardines, mackerel) twice a week delivers the evidence-consistent dose. Algal oil is the plant-appropriate alternative. Plant-based ALA (flaxseed, walnuts) converts to EPA/DHA at only 5–10% efficiency.

6. Magnesium

Magnesium participates in over 300 enzymatic reactions including energy production, neurotransmitter synthesis, and stress-axis regulation. A significant proportion of adults in developed countries consume less than the RDA of 320–420 mg/day, particularly those eating few leafy greens, nuts, or whole grains. A 2024 systematic review of 15 interventional trials in Cureus found supplemental magnesium likely useful for mild anxiety and insomnia in people with low baseline status: 5 of 8 sleep studies and 5 of 7 anxiety studies reported positive results; reviewed depression analyses within that literature found significant score reductions in included RCT subsets (SMD −0.919, p=0.001). Evidence quality is limited by small samples and high heterogeneity — but the safety profile and low cost make it a reasonable first step.

If disrupted sleep is part of the picture alongside low mood, addressing sleep quality alongside magnesium intake tends to produce better results than either approach alone.

Practical guidance: magnesium glycinate or citrate absorbs best. Magnesium oxide — the cheapest form — is primarily a laxative. Practical dose: 200–400 mg at night. Food sources: dark leafy greens, pumpkin seeds, almonds, dark chocolate (70%+), legumes, whole grains.

7. Zinc

Zinc is essential for immune function and neurotransmitter signalling, and zinc-dependent enzymes participate in serotonin and melatonin synthesis. Deficiency is more common in people eating primarily plant-based diets (phytates in whole grains bind zinc and reduce bioavailability). Supplementation studies show modest positive effects in people with clinical depression — but generally in populations with probable pre-existing deficiency. No strong evidence supports supplementation in people who are zinc-replete.

Food sources: oysters (highest per serving), red meat, pumpkin seeds, chickpeas, lentils, hemp seeds. Soaking or sprouting legumes improves zinc bioavailability.

8. Protein adequacy

Neurotransmitters — serotonin, dopamine, noradrenaline — are synthesised from amino-acid precursors. A chronically low-protein diet restricts these raw materials. The 2025–2030 US Dietary Guidelines raised protein recommendations to 1.2–1.6 g/kg/day (approximately 84–112 g/day for a 70 kg adult), up from the previous 0.8 g/kg minimum. A 32-year study of 130,000+ participants, summarised by Harvard T.H. Chan School of Public Health, found protein source matters more than gram count: replacing red and processed meat with plant proteins (nuts, beans, fish) significantly lowered cardiovascular disease and cancer mortality.

Getting macronutrient foundations right — adequate protein, whole-food carbohydrates, quality fats — is the precondition for any nutrient optimisation to work reliably. Food sources: meat, fish, eggs, dairy, legumes, tofu, soy. Plant-based eating covers complete amino-acid profiles through variety.

9. Choline

Choline is the precursor to acetylcholine, the neurotransmitter most tied to learning and memory consolidation. Surveys suggest only 10–12% of adults meet the adequate intake of 425–550 mg/day. Eggs are the most practical everyday source — one large egg yolk provides approximately 125 mg. Vegetarians and vegans are at the highest risk. Food sources: egg yolks, liver, salmon, chicken, soybeans, peanuts, Brussels sprouts. If eating egg-free, consider a choline supplement (250–500 mg/day as bitartrate or CDP-choline).

10. Carbohydrate adequacy

Adequate carbohydrate intake underpins serotonin synthesis: carbohydrates stimulate insulin release, clearing branched-chain amino acids into muscle cells and leaving tryptophan (serotonin's precursor) with preferential brain access. Chronic very-low-carb dieting (below ~50 g/day) produces irritability, low mood, and cognitive sluggishness in a significant subset of people. A 2025 meta-analysis in Scientific Reports found high whole-grain intake associated with 26% lower hypertension risk, and a Harvard analysis found 70 g/day of whole grains linked to 22% lower all-cause mortality. The evidence implicates refined carbohydrates, not carbohydrates as a category.

Food sources: oats, brown rice, wholemeal bread, sweet potatoes, legumes, fruit.

The order of operations

Don't supplement without a reason. The most useful first step is testing: 25(OH)D (vitamin D), B12 (if plant-based or over 60), and ferritin (iron). Fix diet first where possible; supplement where diet genuinely can't cover the gap or where deficiency is confirmed. Most people who feel persistently flat or unmotivated have one or two correctable deficiencies, not ten. Identifying and fixing those typically produces a meaningful change within four to six weeks. If sleep, movement, and stress have already been addressed and you still feel persistently low, nutrient testing is the right next step.

If mood is significantly affecting your daily functioning, speak with a GP or mental health professional. Nutrient optimisation supports wellbeing — it does not substitute for treatment of clinical depression, anxiety, or other mental health conditions.