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Dopamine Brain Food

NS Natural Stacks
4.5
★ ★ ★ ★ ★
(473 ratings)
Vitamin B12 4000 mcg
Phenylalanine 500 mg
Tyrosine 650 mg
Vitamin C 500 mg
Product Image
Score75
A coherent, well-formed focus formula with meaningful precursor amino acids, but high cost, very large B-vitamin amounts, and phenylalanine restrictions narrow its audience.
How scoring works
Quantity:60 Capsule(s) • (20 servings)
Goals:
Energy
Brain Health
Productivity Boost
Mental Focus
General Health
Immunity

Score 75

A coherent, well-formed focus formula with meaningful precursor amino acids, but high cost, very large B-vitamin amounts, and phenylalanine restrictions narrow its audience.
How scoring works
$39.95($1.99 per serving)
iHerb
$ 39.95
Pure Formulas
$ 39.95
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Analysis

Tyrosine and phenylalanine provide direct precursor support for catecholamine pathways involved in focus and mental energy. Trimethylglycine, active B6, methylfolate, and methylcobalamin add a coherent nutrient framework around those amino acids.

The ingredient forms are generally strong and every active amount is disclosed. Folate and B12 are supplied far above basic needs, so the formula is better viewed as a targeted product than an everyday multivitamin substitute.

Three capsules provide meaningful amino-acid amounts but at a high serving cost. Phenylalanine also makes the product completely unsuitable for people with phenylketonuria, and tyrosine creates relevant medication considerations.

Who is it for
  • Adults seeking amino-acid support for mental energy
  • People who value active B-vitamin forms
Best for
  • Tyrosine and phenylalanine precursor support
  • Targeted focus and productivity supplementation

Pros

  • Uses active B6, folate, and B12 forms
  • Provides meaningful tyrosine and phenylalanine amounts
  • Fully discloses each active ingredient

Cons

  • Serving cost is high
  • B12 and folate amounts greatly exceed basic needs
  • Three capsules are required per serving

Warnings

  • People with phenylketonuria must avoid the included phenylalanine
  • Tyrosine and phenylalanine may be unsuitable with MAO inhibitors or levodopa without professional guidance
  • People using thyroid hormone or with hyperthyroidism should discuss the 650 mg tyrosine amount with a clinician

Nutrient quality

83 Highest impact

Pyridoxal-5-phosphate, methylfolate, and methylcobalamin are well-regarded active forms. The principal amino acids and trimethylglycine are supplied in useful amounts.

Ingredient transparency

82 Highest impact

Every active ingredient has a specific amount. Inactive capsule ingredients are not included in the supplied data.

Customer satisfaction

66 High impact

The supplied average and volume indicate generally favorable aggregate satisfaction. No detailed experience reports are available to identify repeated complaints or confirm perceived benefits.

Value for money

65 Moderate impact

High-quality forms support the price, but the serving cost remains difficult to justify. The serving cost is high even with meaningful active amounts.

Report analysis

Goals

Energy
Energy
Impact
Highest effect
A- Goal FitA+ Strength of SupportA- CoverageA Formula Quality
Vitamin B12 · 4000 mcg

Bioactive B vitamins support metabolic energy, while tyrosine and phenylalanine provide building blocks for focus-related neurotransmitters. The formula covers both nutrient metabolism and mental performance with meaningful disclosed amounts.

Methylcobalamin, methylfolate, and pyridoxal phosphate strengthen form quality. People with phenylketonuria must avoid the included L-phenylalanine because they cannot safely metabolize it.

Study evidence
Vitamin B12 Disputed 14 studies
Brain Health
Brain Health
Impact
Highest effect
B+ Goal FitA Strength of SupportB+ CoverageB+ Formula Quality
Folate · 1000 mcg DFEVitamin B12 · 4000 mcgVitamin B6 · 5 mg

Tyrosine and phenylalanine provide direct precursors for dopamine and related catecholamines, supported by active B-vitamin cofactors and methylation nutrients. The formula is well suited to acute mental demand and neurotransmitter synthesis.

Most actives are clearly identified in bioactive forms, although several vitamin amounts are much higher than routine needs. People with phenylketonuria must avoid the 500 mg phenylalanine in this formula.

Study evidence
Folate Supportive 90 studies
Phenylalanine Adverse 77 studies
Tyrosine Supportive 7 studies
Vitamin B12 Supportive 74 studies
Productivity Boost
Productivity Boost
Impact
Highest effect
B+ Goal FitB+ Strength of SupportB CoverageA Formula Quality
Vitamin B12 · 4000 mcgVitamin B12 · 4000 mcgVitamin B6 · 5 mg

Tyrosine and phenylalanine support catecholamine production, while active B vitamins and betaine support methylation. The combination is well aligned with mental energy and focus under demand.

Tyrosine falls below the preferred standalone target, though phenylalanine adds precursor support. People using MAO inhibitors or taking thyroid hormone should discuss the amino-acid combination with a clinician because it may amplify catecholamine or thyroid effects.

Mental Focus
Mental Focus
Impact
Highest effect
B+ Goal FitB+ Strength of SupportB CoverageA Formula Quality
Folate · 1000 mcg DFEVitamin B6 · 5 mgVitamin B12 · 4000 mcg

L-tyrosine and L-phenylalanine provide catecholamine precursors, while P-5-P and methylated B vitamins support their metabolism. The approach is most relevant to focus under acute stress or cognitive demand rather than as a universal daily enhancer.

The precursor amounts are meaningful but below some high-stress research protocols, and every active is clearly listed. L-phenylalanine is unsuitable for people with phenylketonuria because they cannot safely metabolize this amino acid.

Study evidence
Phenylalanine No effect 7 studies
General Health
General Health
Impact
Highest effect
B Goal FitA Strength of SupportB- CoverageB+ Formula Quality
Folate · 1000 mcg DFEVitamin B12 · 4000 mcgVitamin C · 500 mg

High-dose methylcobalamin, active folate, and vitamin B6 support normal energy and neurotransmitter metabolism. Tyrosine, phenylalanine, and betaine create a focused precursor-based formula rather than broad daily nutrition.

The principal amounts and forms are clearly disclosed, and the B12 dose is substantial. People using levodopa or monoamine oxidase inhibitors should discuss the tyrosine and phenylalanine content with a clinician because these amino acids can affect catecholamine pathways.

Study evidence
Folate Supportive 80 studies
Vitamin B12 Adverse 66 studies
Immunity
Immunity
Impact
High effect
B Goal FitB+ Strength of SupportC- CoverageB- Formula Quality
Vitamin C · 500 mg

Vitamin C reaches a useful immune-support amount and is backed by strong nutritional evidence. Active vitamin B6, methylfolate, and methylcobalamin add well-disclosed nutritional support.

The formula is designed mainly for neurotransmitter production rather than immunity. High-dose B vitamins and amino acids do not broaden immune pathway coverage in a meaningful way.

Study evidence
Vitamin C Supportive 53 studies

Ingredients

IngredientAmount per serving
Vitamin C (Quali-C)
 500 mg
Vitamin B6 (Pyridoxal 5-Phosphate)
 5 mg
Folate ((6S)-5-Methyltetrahydrofolate Calcium Salt)
 1000 mcg DFE
Vitamin B12 (Methylcobalamin)
 4000 mcg
L-Tyrosine
650 mg
Trimethylglycine
600 mg
L-Phenylalanine
500 mg
Adults 18–50
Report overview
Vitamin B12 (Methylcobalamin) · 4000 mcg OverallScore85
A- Active Ingredient Quality & BioavailabilityA+ Dose, Safety & Label TransparencyD+ Value

The high methylcobalamin dose is well aligned with people seeking substantial B12 support. Exact form and amount disclosure are clear, while the standard capsule lacks a delivery method designed for absorption through the mouth. The serving is expensive in absolute terms, but its concentrated dose produces moderate cost efficiency per unit of active B12.

View ingredientView products
Phenylalanine · 500 mg OverallScore82
A+ Active Ingredient Quality & BioavailabilityA- Dose, Safety & Label TransparencyD- Value

The clearly identified L-phenylalanine dose fits a targeted nootropic formula and reaches the effective range. The label information does not include a phenylketonuria warning, which matters because people with PKU must avoid phenylalanine. Cost efficiency for the active ingredient remains limited despite the added value of P5P and other supporting nutrients.

View ingredientView products
Tyrosine · 650 mg OverallScore70
B- Active Ingredient Quality & BioavailabilityA+ Dose, Safety & Label TransparencyF Value

Free-form L-Tyrosine is provided at a clearly disclosed dose that fits the usual range for acute cognitive support. The formula also includes several additional nutrients and amino acids, which may suit people seeking a broader blend but adds complexity beyond isolated tyrosine. Cost efficiency is poor because the amount of tyrosine delivered is expensive relative to simpler options.

View ingredientView products
Loading alternative details
74 Performance

True Focus

NOW
<p>A higher tyrosine amount plus phenylalanine, grape-seed extract, DMAE, and ginkgo creates a direct focus-oriented formula without the original’s extremely high vitamin B12 amount. Phenylalanine is still unsuitable for people with phenylketonuria, and the supporting botanicals and DMAE may not fit every user.</p>
74 Performance

Emotional Balance Support

Thorne
<p>Active vitamin B6 and B12 pair with tyrosine, 5-HTP, rhodiola, eleuthero, and GABA for broader mood and stress pathway coverage. The tyrosine amount is lower than the original, and 5-HTP can interact with serotonergic medicines, so this is not a simple swap.</p>
68 Performance

Triple Action Thyroid

Life Extension
<p>Methylcobalamin, tyrosine, fermented ginseng, and branded ashwagandha broaden support for energy and stress. The formula is less focused on tyrosine and phenylalanine, and its iodine, guggul, and ashwagandha create thyroid-specific cautions that the original does not share.</p>
74 Budget

True Focus

NOW
<p>The substantially lower serving cost retains both tyrosine and phenylalanine, with more tyrosine than the original. It uses less phenylalanine and omits methylfolate, methylcobalamin, and trimethylglycine, while ginkgo and phenylalanine add their own suitability considerations.</p>
63 Budget

Anti-Fatigue

Kroeger Herb Products Co.
<p>The lower-cost formula keeps vitamin C and several B vitamins for general energy support. It removes tyrosine, phenylalanine, methylfolate, and trimethylglycine, while very high pantothenic acid, high vitamin B12, and an unspecified licorice amount make it a weak direct substitute.</p>
68 Budget

Triple Action Thyroid

Life Extension
<p>The lower serving cost retains methylcobalamin and tyrosine while adding ashwagandha and fermented ginseng for a broader energy and stress focus. The tyrosine amount is much lower, phenylalanine and trimethylglycine are absent, and iodine, guggul, and ashwagandha require care with thyroid conditions or medication.</p>
74 Value

True Focus

NOW
<p>The combination of 800 mg tyrosine and 300 mg phenylalanine preserves the original’s central amino-acid strategy at a much lower serving cost. It drops active folate, methylcobalamin, and trimethylglycine, and the added ginkgo and DMAE change the safety and tolerance profile.</p>
63 Value

Anti-Fatigue

Kroeger Herb Products Co.
<p>Vitamin C and several B vitamins provide inexpensive basic energy-metabolism coverage. The formula offers poor ingredient matching because tyrosine, phenylalanine, methylfolate, and trimethylglycine are absent, while high pantothenic acid and an unspecified licorice amount add uncertainty.</p>
68 Value

Triple Action Thyroid

Life Extension
<p>Methylcobalamin, tyrosine, ashwagandha, and fermented ginseng offer broader energy support at lower serving cost. The modest tyrosine amount and absence of phenylalanine and trimethylglycine reduce direct fit, while the thyroid-focused ingredients require careful screening.</p>
Report alternatives

Sources

Published studies used for the product analysis and the top-ranked studies for each ingredient and goal.

  1. Cognition after a 4-week high phenylalanine intake in adults with phenylketonuria - a randomized controlled trial.
    Trepp R; Muri R; Maissen-Abgottspon S; Haynes AG; Hochuli M; Everts R · The American journal of clinical nutrition · 2024
    Randomized trial30 participantsMental Focus forPhenylalanine
  2. Are Functional Brain Networks Sensitive to High Phenylalanine in Adults With Phenylketonuria?
    Vallesi V; Morishima Y; Winiger L; Trepp R; Everts R; Muri R · JIMD reports · 2026
    Randomized trial23 participantsMental Focus forPhenylalanine
  3. Neuropsychological assessment among children and adolescents with phenylketonuria and hyperphenylalaninemia and its relationship with plasma phenylalanine levels.
    González García MB; Conde-Guzon P; Alcalde Martín C; Conde-Guzon MJ; Velasco Zúñiga R · Archivos argentinos de pediatria · 2018
    Observational study26 participantsMental Focus forPhenylalanine
  4. Sustained attention in untreated non-PKU-hyperphenylalaninemia.
    Weglage J; Schmidt E; Fünders B; Pietsch M; Ullrich K · Journal of clinical and experimental neuropsychology · 1997
    Case-control study48 participantsMental Focus forPhenylalanine
  5. Efficacy of Vitamin C as Glucocorticoid Substitute for Reducing Pain and Inflammation After Total Hip Arthroplasty: A Randomized Controlled Trial.
    Jiang W; Xu H; Jiang X; Zhan Y; Ju Y; Xie J; Huang Z; Huang Q; Pei F · The Journal of bone and joint surgery. American volume · 2025
    Randomized trial107 participantsAnti-Inflammatory Support forVitamin C
  6. The Impact of Vitamin C on Analgesic, Anti-inflammatory, and Hemostatic Outcomes After Total Hip and Knee Arthroplasty: A Systematic Review and Meta-Analysis.
    Moftakhari Hajimirzaei S; Bagherzadeh Cham M; Dolikhani M; Tabatabaee SM; Ebrahimpour A · The archives of bone and joint surgery · 2026
    Meta-analysis1,162 participants10 studies pooledAnti-Inflammatory Support forVitamin C
  7. The impact of vitamin C supplementation on the perioperative outcomes after total hip and knee arthroplasty: a systematic review and meta-analysis.
    Liu X; Guo J; Li Y; Yang Y; Liu M; Gao Q; Yang Y; Wu X; Yue C · BMC musculoskeletal disorders · 2026
    Meta-analysis852 participants8 studies pooledAnti-Inflammatory Support forVitamin C
  8. Therapeutic Impact of Ascorbic Acid on Oral and Periodontal Tissues: A Systematic Literature Review.
    Ruzijevaite G; Acaite E; Jagelaviciene E · Medicina (Kaunas, Lithuania) · 2025
    Systematic review811 participants17 studies pooledAnti-Inflammatory Support forVitamin C
  9. Oral vitamin C administration reduces early recurrence rates after electrical cardioversion of persistent atrial fibrillation and attenuates associated inflammation.
    Korantzopoulos P; Kolettis TM; Kountouris E; Dimitroula V; Karanikis P; Pappa E; Siogas K; Goudevenos JA · International journal of cardiology · 2005
    Randomized trial44 participantsAnti-Inflammatory Support forVitamin C
  10. B vitamins and prevention of cognitive decline and incident dementia: a systematic review and meta-analysis.
    Wang Z; Zhu W; Xing Y; Jia J; Tang Y · Nutrition reviews · 2022
    Meta-analysis46,175 participants95 studies pooledBrain Health forFolate
  11. Folate and long-chain polyunsaturated fatty acid supplementation during pregnancy has long-term effects on the attention system of 8.5-y-old offspring: a randomized controlled trial.
    Catena A; Muñoz-Machicao JA; Torres-Espínola FJ; Martínez-Zaldívar C; Diaz-Piedra C; Gil A; Haile G; Györei E; Molloy AM; Decsi T; Koletzko B; Campoy C · The American journal of clinical nutrition · 2016
    Randomized trial136 participantsBrain Health forFolate
  12. Folic acid supplementation improves cognitive function in participants with cerebral small vascular disease-related cognitive impairment: a randomized controlled trial.
    Liu Y; Yu Z; Cai Z; Zhao L; Wang Y; Guo Y; Su X; Miao Y; Yi B; Wang Y; Zhang X · The journal of prevention of Alzheimer's disease · 2025
    Randomized trial220 participantsBrain Health forFolate
  13. Circulating folate concentrations and the risk of mild cognitive impairment: A prospective study on the older Chinese population without folic acid fortification.
    Fu J; Liu Q; Zhu Y; Sun C; Duan H; Huang L; Zhou D; Wang Z; Zhao J; Li Z; Ma F; Li W; Liu H; Zhang X; Chen Y; Wang G; Du Y; Huang G · European journal of neurology · 2022
    Cohort study3,974 participantsBrain Health forFolate
  14. Normal-But-Low Serum Folate Levels and the Risks for Cognitive Impairment.
    Jang S; Han JW; Shin J; Kim TH; Kwak KP; Kim K; Kim BJ; Kim SG; Kim JL; Kim TH; Moon SW; Park JY; Park JH; Byun S; Suh SW; Seo J; So Y; Ryu SH; Youn JC; Lee KH; Lee DY; Lee DW; Lee SB; Lee JJ; Lee JR; Jeong H; Jeong HG; Jhoo JH; Han K; Hong JW; Kim KW · Psychiatry investigation · 2020
    Cohort study3,910 participantsBrain Health forFolate
  15. The Association between Dietary Amino Acid Intake and Cognitive Decline 8 Years Later in Japanese Community-Dwelling Older Adults.
    Kinoshita K; Otsuka R; Takada M; Tsukamoto-Yasui M; Nishita Y; Tange C; Tomida M; Shimokata H; Kuzuya M; Imaizumi A; Arai H · The journal of nutrition, health & aging · 2021
    Cohort study427 participantsBrain Health forPhenylalanine
  16. Magnetic resonance imaging in phenylketonuria: reversal of cerebral white matter change.
    Cleary MA; Walter JH; Wraith JE; White F; Tyler K; Jenkins JP · The Journal of pediatrics · 1995
    Non-randomized trial41 participantsBrain Health forPhenylalanine
  17. [Cross-sectional association between the amino acid intake and episodic memory in middle- and old-aged community dwellers].
    Kinoshita K; Otsuka R; Takada M; Tsukamoto-Yasui M; Nishita Y; Tange C; Tomida M; Shimokata H; Imaizumi A; Arai H · Nihon Ronen Igakkai zasshi. Japanese journal of geriatrics · 2021
    Cross-sectional study2,082 participantsBrain Health forPhenylalanine
  18. Improved dietary control results in improvements in indices of white matter structure in adults with phenylketonuria: the ReDAPT study.
    Kang MJY; Adamson C; Malpas CB; Winton-Brown T; Burgess N; Fazio T; Velakoulis D; Desmond P; Venkatraman V; De Jong G; Walterfang M · Acta neuropsychiatrica · 2026
    Single-arm trial7 participantsBrain Health forPhenylalanine
  19. [Brain white matter lesions of children with phenylketonuria before and after treatment].
    Wang ZX; Zhou ZS; Yu WM · Zhongguo dang dai er ke za zhi = Chinese journal of contemporary pediatrics · 2006
    Single-arm trial19 participantsBrain Health forPhenylalanine
  20. Combined L-carnosine and L-tyrosine supplementation as an ergogenic strategy for physical and cognitive performance under fatigue in professional football players.
    Bilgin S; Bozyılan E; Buzdağlı Y; Karaç Öcal Y; Gürkan O; Toktaş S; İnan H; Egil İ; Yarayan YE · Frontiers in nutrition · 2026
    Randomized trial24 participantsBrain Health forTyrosine
  21. Effect of tyrosine supplementation on clinical and healthy populations under stress or cognitive demands--A review.
    Jongkees BJ; Hommel B; Kühn S; Colzato LS · Journal of psychiatric research · 2016
    Narrative reviewBrain Health forTyrosine
  22. Influence of nutritional tyrosine on cognition and functional connectivity in healthy old humans.
    Hensel C; Becker M; Düzel S; Demuth I; Norman K; Steinhagen-Thiessen E; Gallinat J; Lindenberger U; Kühn S · NeuroImage · 2019
    Cross-sectional study286 participantsBrain Health forTyrosine
  23. Dietary Tyrosine Intake (FFQ) Is Associated with Locus Coeruleus, Attention and Grey Matter Maintenance: An MRI Structural Study on 398 Healthy Individuals of the Berlin Aging Study-II.
    Plini ERG; Melnychuk MC; Harkin A; Dahl MJ; McAuslan M; Kühn S; Boyle RT; Whelan R; Andrews R; Düzel S; Drewelies J; Wagner GG; Lindenberger U; Norman K; Robertson IH; Dockree PM · The journal of nutrition, health & aging · 2023
    Cross-sectional study398 participantsBrain Health forTyrosine
  24. Baseline-dependent effect of dopamine's precursor L-tyrosine on working memory gating but not updating.
    Jongkees BJ · Cognitive, affective & behavioral neuroscience · 2021
    Randomized trial45 participantsBrain Health forTyrosine
  25. Relationship between vitamin B12 levels and motor development: A systematic review.
    Dos Santos MERA; da Silva KG; da Silva Souza AP; da Silva ABJ; da Silva RF; da Silva EHA; de Souza SL; Barros WMA · Clinical nutrition ESPEN · 2024
    Systematic review1,559 participants8 studies pooledBrain Health forVitamin B12
  26. Vitamin B12 supplementation improves cognitive function in middle aged and elderly patients with cognitive impairment.
    Zhou L; Bai X; Huang J; Tan Y; Yang Q · Nutricion hospitalaria · 2023
    Randomized trial115 participantsBrain Health forVitamin B12
  27. Structural and Functional Brain Changes Associated with Vitamin B12 Deficiency using Magnetic Resonance Imaging: A Systematic Review and Meta-analysis.
    Alghamdi A · Current medical imaging · 2023
    Meta-analysis12 studies pooledBrain Health forVitamin B12
  28. Maternal vitamin B12, vitamin D, and folic acid status during pregnancy and child neurodevelopment: a systematic review.
    Franco L; de Andrade CVF; Margini LV; Sousa N · Frontiers in neuroscience · 2026
    Systematic review22 studies pooledBrain Health forVitamin B12
  29. Higher vitamin B12 from mid- to late life is related to slower rates of cognitive decline.
    Marino FR; Rogers G; Miller JW; Selhub J; Mez J; Crane PK; Mukherjee S; Saykin AJ; Hohman TJ; Trittschuh EH; Au R; Jacques PF; Hwang PH · Alzheimer's & dementia : the journal of the Alzheimer's Association · 2025
    Cohort study1,994 participantsBrain Health forVitamin B12
  30. A new perspective on vitamin B12 deficiency in rheumatology: a case-based review.
    Dułak NA; Rytlewska M; Jaskólska M; Chmielewski M · Rheumatology international · 2024
    Case series3 participantsEnergy forVitamin B12
  31. Effects of Vitamin B12 Supplementation on Cognitive Function, Depressive Symptoms, and Fatigue: A Systematic Review, Meta-Analysis, and Meta-Regression.
    Markun S; Gravestock I; Jäger L; Rosemann T; Pichierri G; Burgstaller JM · Nutrients · 2021
    Meta-analysis6,276 participants16 studies pooledEnergy forVitamin B12
  32. Patients' experiences with methylcobalamin injections in amyotrophic lateral sclerosis.
    Zubair AS; Saab L; Scharer K; Khokhar B · Brain circulation · 2024
    Qualitative study5 participantsEnergy forVitamin B12
  33. Cobalamin deficiency: clinical picture and radiological findings.
    Briani C; Dalla Torre C; Citton V; Manara R; Pompanin S; Binotto G; Adami F · Nutrients · 2014
    Narrative reviewEnergy forVitamin B12
  34. Vitamin B12 Deficiency: Common Questions and Answers.
    Patel H; McGuirk R · American family physician · 2025
    Narrative reviewEnergy forVitamin B12
  35. Intakes of Folate, Vitamin B6, and Vitamin B12 in Relation to All-Cause and Cause-Specific Mortality: A National Population-Based Cohort.
    Bo Y; Xu H; Zhang H; Zhang J; Wan Z; Zhao X; Yu Z · Nutrients · 2022
    Cohort study55,569 participantsGeneral Health forFolate
  36. The responsiveness of plasma homocysteine to small increases in dietary folic acid: a primary care study.
    Schorah CJ; Devitt H; Lucock M; Dowell AC · European journal of clinical nutrition · 1998
    Randomized trial119 participantsGeneral Health forFolate
  37. Associations of Serum Folate and Homocysteine Concentrations with All-Cause, Cardiovascular Disease, and Cancer Mortality in Men and Women in Korea: the Cardiovascular Disease Association Study.
    Song S; Song BM; Park HY · The Journal of nutrition · 2023
    Cohort study21,260 participantsGeneral Health forFolate
  38. The concept of folic acid supplementation and its role in prevention of neural tube defect among pregnant women: PRISMA.
    Seyoum Tola F · Medicine · 2024
    Systematic reviewGeneral Health forFolate
  39. Systematic review of adverse health outcomes associated with high serum or red blood cell folate concentrations.
    Colapinto CK; O'Connor DL; Sampson M; Williams B; Tremblay MS · Journal of public health (Oxford, England) · 2017
    Systematic review71,847 participants46 studies pooledGeneral Health forFolate
  40. Oral Vitamin B12 versus Placebo for the Prevention of Chemotherapy-Induced Peripheral Neuropathy in Gynecological Cancer Patients: A Randomized, Double-Blind, Placebo-Controlled Trial.
    Insin P; Chaiwongsa T; Prueksaritanond N · Asian Pacific journal of cancer prevention : APJCP · 2026
    Randomized trial40 participantsGeneral Health forVitamin B12
  41. Vitamin B12 Supplementation in Diabetic Neuropathy: A 1-Year, Randomized, Double-Blind, Placebo-Controlled Trial.
    Didangelos T; Karlafti E; Kotzakioulafi E; Margariti E; Giannoulaki P; Batanis G; Tesfaye S; Kantartzis K · Nutrients · 2021
    Randomized trial90 participantsGeneral Health forVitamin B12
  42. A single-center randomized controlled trial of local methylcobalamin injection for subacute herpetic neuralgia.
    Xu G; Lv ZW; Feng Y; Tang WZ; Xu GX · Pain medicine (Malden, Mass.) · 2014
    Randomized trial98 participantsGeneral Health forVitamin B12
  43. Local Injection of Methylcobalamin Combined with Lidocaine for Acute Herpetic Neuralgia.
    Xǔ G; Xu S; Tang WZ; Xú G; Cheng C; Xu J · Pain medicine (Malden, Mass.) · 2017
    Randomized trial204 participantsGeneral Health forVitamin B12
  44. The Effect of Vitamin B12 and Folic Acid Supplementation on Serum Homocysteine, Anemia Status and Quality of Life of Patients with Multiple Sclerosis.
    Nozari E; Ghavamzadeh S; Razazian N · Clinical nutrition research · 2022
    Clinical trial50 participantsGeneral Health forVitamin B12
  45. Vitamin C and contribution to the normal function of the immune system: evaluation of a health claim pursuant to Article 14 of Regulation (EC) No 1924/2006.
    EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) · EFSA journal. European Food Safety Authority · 2026
    Guideline / consensusImmunity forVitamin C
  46. Therapeutic effects of high-dose vitamin C supplementation in patients with COVID-19: a meta-analysis.
    Sun L; Zhao JH; Fan WY; Feng B; Liu WW; Chen RQ; Ban C; Dang AG; Wang M; Luo KT; Zhou GY; Yu FF; Ba Y · Nutrition reviews · 2024
    Meta-analysis2,334 participants14 studies pooledImmunity forVitamin C
  47. Effect of micronutrient supplements on influenza and other respiratory tract infections among adults: a systematic review and meta-analysis.
    Abioye AI; Bromage S; Fawzi W · BMJ global health · 2021
    Meta-analysisImmunity forVitamin C
  48. New evidence for antioxidant properties of vitamin C.
    Vojdani A; Bazargan M; Vojdani E; Wright J · Cancer detection and prevention · 2001
    Randomized trial20 participantsImmunity forVitamin C
  49. Enhanced Vitamin C Delivery: A Systematic Literature Review Assessing the Efficacy and Safety of Alternative Supplement Forms in Healthy Adults.
    Calder PC; Kreider RB; McKay DL · Nutrients · 2025
    Systematic review13 studies pooledImmunity forVitamin C
  50. A systematic review of cognitive functioning in early treated adults with phenylketonuria.
    Hofman DL; Champ CL; Lawton CL; Henderson M; Dye L · Orphanet journal of rare diseases · 2019
    Systematic review16 studies pooledMental Focus forPhenylalanine
  51. Effects of L-histidine depletion and L-tyrosine/L-phenylalanine depletion on sensory and motor processes in healthy volunteers.
    van Ruitenbeek P; Sambeth A; Vermeeren A; Young SN; Riedel WJ · British journal of pharmacology · 2009
    Clinical trial17 participantsMental Focus forPhenylalanine
  52. Evaluation of the anti-wrinkle effect of an ascorbic acid-loaded dissolving microneedle patch via a double-blind, placebo-controlled clinical study.
    Lee C; Yang H; Kim S; Kim M; Kang H; Kim N; An S; Koh J; Jung H · International journal of cosmetic science · 2017
    Randomized trial23 participantsSkin Health forVitamin C
  53. Comparative Study on the Outcome of Periorbital Wrinkles Treated with Laser-Assisted Delivery of Vitamin C or Vitamin C Plus Growth Factors: A Randomized, Double-blind, Clinical Trial.
    Machado BHB; Frame J; Zhang J; Najlah M · Aesthetic plastic surgery · 2021
    Randomized trial149 participantsSkin Health forVitamin C
  54. Randomized trial of topical ascorbic acid in DMSO versus imiquimod for the treatment of basal cell carcinoma.
    Burke B; Bailie JE · Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie · 2022
    Randomized trial25 participantsSkin Health forVitamin C
  55. Vitamin C improves healing of foot ulcers: a randomised, double-blind, placebo-controlled trial.
    Gunton JE; Girgis CM; Lau T; Vicaretti M; Begg L; Flood V · The British journal of nutrition · 2022
    Randomized trial16 participantsSkin Health forVitamin C
  56. Dietary nutrient intakes and skin-aging appearance among middle-aged American women.
    Cosgrove MC; Franco OH; Granger SP; Murray PG; Mayes AE · The American journal of clinical nutrition · 2007
    Cross-sectional study4,025 participantsSkin Health forVitamin C