Energy

Energy

Bayer One A Day4.7 (125 ratings)
Format:Tablet Quantity: 50 Tablet(s) · 50 servings
Goals
$10.90 $0.21 per serving

Product analysis

48 out of 100

Energy brings vitamins and minerals together with caffeine in one supplement. Most nutrient forms are not specified, making exact ingredient comparisons harder.

AI assessment of the formula, label and price. How scoring works

Nutrient Quality23

Most nutrient forms are unspecified, leaving their quality uncertain. Some forms are identified elsewhere in the ingredient list, but the proportions of several mineral sources remain unclear.

Ingredient Transparency67

Ingredient amounts are clearly listed, helping you compare servings. Some ingredient forms are named, while others remain unclear.

Value For Money54

Several minerals offer favorable value, while niacin and biotin offer more moderate value. Value for many other nutrients and caffeine remains uncertain, and the calcium and copper comparisons are older.

Customer Satisfaction72

Customer feedback is very positive. The number of reviews gives more context to satisfaction but does not establish effectiveness or safety.

Product Focus42

The ingredient mix has support across several intended goals, though benefits remain uncertain. None of the ingredients is confirmed to be unnecessary.

Format
Tablet
Container
50 Tablet(s)
Per serving
$0.21
Customer rating
4.7 · 125 ratings
Report analysis

Goals

Impact
High effect
C Ingredient FitD PathwaysA+ EvidenceA+ Formulation Logic
Iodine · 150 mcgVitamin D · 10 mcgVitamin B5 · 10 mgMagnesium · 40 mgRiboflavin · 3.4 mgThiamin · 3 mgVitamin B12 · 12 mcgIron · 9 mgCaffeine · 90 mg

Caffeine supports acute alertness and reduced sleepiness, with 90 mg per serving. Iron, folate and several B vitamins also have roles in addressing fatigue associated with low nutrient intake, alongside vitamin C. These nutritional roles do not establish extra energy when intake is adequate. The low magnesium amount and the supplied B12 and vitamin D amounts did not contribute to the saved result.

How this product is rated for Energy

Ingredient fit63

Several nutrients contribute through their nutritional roles, with varying amounts and additional ingredients outside those roles.
Goal fit
The relevant nutrients share the formula with other actives, so the product's focus extends beyond energy.
Dose adequacy
Amounts vary across the contributing nutrients; excluded low amounts do not establish a lack of nutritional value.

Pathways45

Alertness is the only supported route among those evaluated. Broader exercise and cellular-energy coverage is absent.
Depth
Caffeine provides the strongest contribution through alertness.
Breadth
Alertness is the only route meeting the saved coverage threshold.

Evidence99

Caffeine supplies the strongest relevant evidence for acute alertness. The qualifying ingredients meet the saved preparation criteria.
Evidence strength
Caffeine provides the strongest relevant evidence, specifically for acute alertness and reduced sleepiness.
Studied preparation
Most qualifying nutrient declarations meet the saved preparation criteria; iodine does not.

Formulation logic100

The contributing ingredients meet the saved minimum amount and partner conditions. No configured conflict was identified.
Partner coverage
The contributing ingredients do not require an additional partner under the supplied findings.
Conflicts
No configured ingredient conflict was identified in the supplied facts.
Effective doses
All ingredients counted in the saved result meet its minimum amount criterion; that criterion does not guarantee a noticeable benefit.
Study evidence
Caffeine Supportive 68 studies
Iodine Adverse 3 studies
Iron Supportive 74 studies
Magnesium Supportive 4 studies
Thiamin Disputed 12 studies
Vitamin D Supportive 32 studies
Mental Focus
Impact
High effect
B- Ingredient FitC- PathwaysB EvidenceA+ Formulation Logic
Folate · 665 mcg DFEVitamin B6 · 4 mgVitamin D · 10 mcgVitamin B12 · 12 mcgMagnesium · 40 mgCaffeine · 90 mg

Caffeine supplies the most direct support for alertness and sustained attention. Folate, iron, vitamin B12, thiamin and niacin can help concentration when low intake or deficiency impairs it. These nutritional roles are separate from an immediate stimulant effect and do not establish extra focus when intake is adequate.

How this product is rated for Mental Focus

Ingredient fit72

Caffeine contributes immediate alertness alongside nutrients relevant to deficiency-related concentration problems. The declared amounts provide uneven coverage of the saved amount ranges; some contributions remain partial.
Goal fit
Caffeine contributes immediate alertness alongside nutrients relevant to deficiency-related concentration problems.
Dose adequacy
The declared amounts provide uneven coverage of the saved amount ranges; some contributions remain partial.

Pathways56

Caffeine dominates the immediate alertness finding.
Depth
Caffeine dominates the immediate alertness finding.
Breadth
Only the alertness route reaches the saved coverage threshold.

Evidence79

Caffeine provides the clearest direct acute attention evidence.
Evidence strength
Caffeine provides the clearest direct acute attention evidence.
Studied preparation
The saved preparation match is complete for the ingredients that meet its amount criterion; this does not establish consistent focus benefit.

Formulation logic100

The represented ingredients have no missing required partner in the saved finding. No specified ingredient conflict was identified in the saved findings.
Partner coverage
The represented ingredients have no missing required partner in the saved finding.
Conflicts
No specified ingredient conflict was identified in the saved findings.
Effective doses
All ingredients counted by this rule reach its minimum amount criterion; that threshold is not a clinically proven effective dose.
Study evidence
Caffeine Supportive 128 studies
Folate Mixed 12 studies
Iodine No effect 17 studies
Iron Adverse 33 studies
Magnesium Supportive 6 studies
Zinc Mixed 16 studies
Hair Health
Impact
High effect
C+ Ingredient FitF PathwaysA+ EvidenceA+ Formulation Logic
Biotin · 300 mcgVitamin D · 10 mcgZinc · 15 mgIron · 9 mgVitamin C · 60 mg

Zinc and iron can contribute to hair health when inadequate intake is associated with shedding. Copper supports normal pigmentation and connective tissue, while selenium supports antioxidant functions; these roles do not establish routine regrowth. Biotin is present but received no meaningful amount recognition in the saved findings. The broader vitamin mixture does not establish additional hair benefit from combining these ingredients.

How this product is rated for Hair Health

Ingredient fit66

The formula includes hair-relevant nutrients, alongside broader nutritional ingredients. Several contributions depend on intake, amount or preparation rather than establishing routine regrowth.
Goal fit
Relevant nutrients share the formula with ingredients aimed at other goals, making its hair focus less concentrated.
Dose adequacy
The amounts provide partial coverage of the saved comparisons rather than uniformly matching their reference exposures.

Pathways14

The strongest coverage concerns antioxidant functions, with limited breadth across the other assessed hair mechanisms.
Depth
Antioxidant-related nutrients provide the strongest coverage; normal antioxidant functions do not by themselves establish hair regrowth.
Breadth
The formula does not reach the saved coverage level in any assessed hair mechanism.

Evidence97

The leading ingredient findings must be read alongside their nutritional and preparation limits. Recognition in the saved comparisons does not establish routine regrowth from this product.
Evidence strength
Zinc leads the ingredient findings, with hair benefits most relevant when intake is inadequate.
Studied preparation
Most recognized preparations match the saved comparison, while iodine lacks a studied hair preparation.

Formulation logic100

Required partners are accounted for and no configured conflicts were found. The amount findings describe comparison coverage, without proving combined hair benefit.
Partner coverage
No required ingredient partner is missing from the saved findings; this does not imply added benefit from combining ingredients.
Conflicts
No configured ingredient conflict was identified; unassessed interactions and suitability remain unresolved.
Effective doses
All ingredients included in this amount check reach its minimum comparison level; that level is not a proven effective hair dose.
Study evidence
Biotin Supportive 4 studies
Copper Adverse 4 studies
Folate Mixed 15 studies
Iodine No effect 1 study
Iron Disputed 25 studies
Niacin Disputed 2 studies
Selenium Disputed 7 studies
Vitamin A Disputed 13 studies
Vitamin D Disputed 34 studies
Vitamin E No effect 3 studies
Zinc Supportive 22 studies
Impact
High effect
C Ingredient FitC PathwaysA+ EvidenceA+ Formulation Logic
Vitamin K · 25 mcgMagnesium · 40 mgCalcium · 250 mgVitamin D · 10 mcgCopper · 2 mgManganese · 2 mgZinc · 15 mgVitamin C · 60 mg

Calcium supplies bone mineral; its 250 mg per serving can help fill a dietary gap, without establishing extra benefit when intake is already adequate. Vitamin D supports calcium absorption and deficiency-related mineralization; routine extra supplementation has not established fracture prevention in generally healthy adults. Magnesium supports normal bone metabolism when intake is low, although routine fracture prevention is unproven. Vitamin C supports collagen formation and copper helps cross-link it, with the clearest skeletal benefit from correcting deficiency.

How this product is rated for Bone Health

Ingredient fit63

Minerals provide a nutritional route to supporting bones, with the contribution depending on the declared amount and dietary need.
Goal fit
Bone-related nutrients sit within a broader formula containing ingredients aimed at other needs.
Dose adequacy
The declared amounts provide partial or mixed coverage of the nutritional and preparation references; lower amounts limit the contribution.

Pathways60

The main represented roles are collagen matrix formation. Other bone-related roles receive less or no coverage.
Depth
The strongest represented role is collagen matrix formation. This describes ingredient coverage, not a demonstrated change in bone health.
Breadth
The main represented roles are collagen matrix formation. Other bone-related roles receive less or no coverage.

Evidence100

Calcium supports mineralization when dietary intake is insufficient; fracture outcomes remain mixed.
Evidence strength
Calcium supports mineralization when dietary intake is insufficient; fracture outcomes remain mixed.
Studied preparation
The saved findings identify the counted preparations as matching study preparations; that match does not establish fracture prevention.

Formulation logic100

The counted ingredients either have their specified nutritional partner or can contribute independently. No configured ingredient conflict was identified in the supplied findings.
Partner coverage
The counted ingredients either have their specified nutritional partner or can contribute independently.
Conflicts
No configured ingredient conflict was identified in the supplied findings.
Effective doses
The counted ingredients meet the saved minimum amount comparison; this does not make those amounts proven effective doses for preventing fractures.
Study evidence
Calcium Supportive 144 studies
Copper Disputed 20 studies
Folate Supportive 50 studies
Magnesium Supportive 48 studies
Manganese Adverse 12 studies
Vitamin A Adverse 56 studies
Vitamin C Supportive 46 studies
Vitamin D Supportive 202 studies
Vitamin K Supportive 78 studies
Zinc Supportive 33 studies

Ingredients

IngredientAmount per servingScore
Vitamin A (Beta-Carotene)
1050 mcg
Vitamin C
60 mg
Vitamin D
10 mcg
Vitamin E
10.1 mg
Vitamin K
25 mcg
Thiamine
3 mg
Riboflavin
3.4 mg
Niacin
40 mg 73
Vitamin B6
4 mg
Folate
665 mcg DFE
Vitamin B12
12 mcg
Biotin
300 mcg 56
Pantothenic Acid
10 mg
Calcium
250 mg 52
Iron
9 mg 47
Iodine
150 mcg 88
Magnesium
40 mg
Zinc
15 mg
Selenium
45 mcg
Copper
2 mg 57
Manganese
2 mg 58
Chromium
100 mcg 32
Molybdenum
25 mcg 46
Caffeine
90 mg 73
Adults 18–50
Report overview
Iodine · 150 mcg OverallScore88
C+ Active Ingredient Quality & BioavailabilityA+ Dose, Safety & Label TransparencyA+ Value
Caffeine · 90 mg OverallScore73
D- Active Ingredient Quality & BioavailabilityA Dose, Safety & Label TransparencyA+ Value
Each serving lists 90 mg of caffeine. The whole-product serving costs about $0.22.
How this ingredient is rated

Active Ingredient Quality & Bioavailability40

Caffeine is identified, but the available form data do not specify a distinct preparation or establish a release advantage.
Advanced Bioavailability and Release Profiles
Caffeine is identified, but the available form data do not specify a distinct preparation or establish a release advantage.

Dose, Safety & Label Transparency92

The stated 90 mg of caffeine per serving is a mild amount. The evaluated ingredient panel lists no secondary stimulants.
Caffeine Dose Transparency
The label states 90 mg of caffeine per serving.
Dosage Efficacy and Safety Margin
The stated 90 mg of caffeine per serving is a mild amount.
Secondary Stimulant Disclosure and Risk
The evaluated ingredient panel lists no secondary stimulants.

Value100

The whole-product serving costs about $0.22, on the lower end of the evaluated prices.
Price Per Serving vs. Collection Median
The whole-product serving costs about $0.22, on the lower end of the evaluated prices.
Calcium · 250 mg OverallScore52
F Active Ingredient Quality & BioavailabilityD- Dose, Safety & Label TransparencyA+ Value
Each serving provides 250 mg of calcium, but the source of that amount is uncertain. Several calcium compounds appear in the other ingredients, and an artificial additive is flagged.
How this ingredient is rated

Active Ingredient Quality & Bioavailability37

Calcium carbonate, dicalcium phosphate, and calcium D-pantothenate appear in the other ingredients, but the source of the listed calcium remains uncertain.
Calcium Form & Absorption Potential
Calcium carbonate, dicalcium phosphate, and calcium D-pantothenate appear in the other ingredients; the source of the stated calcium amount is not fully known.
Elemental Calcium Transparency
The label specifies 250 mg of elemental calcium per serving.

Dose, Safety & Label Transparency42

A serving supplies 250 mg of calcium. The evaluation flags an artificial additive in the ingredients.
Absorption-Optimized Serving Dose
A serving supplies 250 mg of calcium.
Formulation Purity & Additives
The evaluation flags an artificial additive in the ingredients.

Value100

At about $0.22 per whole-product serving, the price covers the entire product.
Price Per Serving Efficiency
A whole-product serving costs about $0.22.
Report alternatives

Sources

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

  1. What is the impact of daily oral supplementation of vitamin D3 (cholecalciferol) plus calcium on the incidence of hip fracture in older people? A systematic review and meta-analysis.
    Manoj P; Derwin R; George S · International journal of older people nursing · 2023
    Meta-analysis12,620 participants7 studies pooledBone Health forCalcium
  2. Calcium supplementation prevents seasonal bone loss and changes in biochemical markers of bone turnover in elderly New England women: a randomized placebo-controlled trial.
    Storm D; Eslin R; Porter ES; Musgrave K; Vereault D; Patton C; Kessenich C; Mohan S; Chen T; Holick MF; Rosen CJ · The Journal of clinical endocrinology and metabolism · 1998
    Randomized trial60 participantsBone Health forCalcium
  3. The effects of calcium supplementation (milk powder or tablets) and exercise on bone density in postmenopausal women.
    Prince R; Devine A; Dick I; Criddle A; Kerr D; Kent N; Price R; Randell A · Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research · 1995
    Randomized trial168 participantsBone Health forCalcium
  4. The efficacy of calcium supplementation alone in elderly Thai women over a 2-year period: a randomized controlled trial.
    Rajatanavin R; Chailurkit L; Saetung S; Thakkinstian A; Nimitphong H · Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA · 2014
    Randomized trial404 participantsBone Health forCalcium
  5. Calcium-enriched foods and bone mass growth in prepubertal girls: a randomized, double-blind, placebo-controlled trial.
    Bonjour JP; Carrie AL; Ferrari S; Clavien H; Slosman D; Theintz G; Rizzoli R · The Journal of clinical investigation · 1997
    Randomized trial149 participantsBone Health forCalcium
  6. The Association between Dietary and Circulating Copper Levels and Osteoporosis: a Scoping Review.
    Ju Y; Xiong W; Pang Y; Chen Z; Hou J; Zheng S; Li Z; Liu T; Xia H; Xia M; Zhong Y; Li J; Jiang X · Biological trace element research · 2026
    Scoping review18 studies pooledBone Health forCopper
  7. Association between dietary copper, iron, zinc, selenium intake and osteopenia or osteoporosis in elderly hypertensive patients: a retrospective cohort study.
    Chen M; Jia L; Gao R · Frontiers in nutrition · 2024
    Cohort study5,286 participantsBone Health forCopper
  8. Associations of dietary copper intake with total bone mineral density and lumbar spine bone mineral density in American adults.
    Hu M; Wang Z; Li C; Zheng Y; Hu J · Medicine · 2025
    Cross-sectional studyBone Health forCopper
  9. The association between dietary mineral intake and bone mineral density: a cross-sectional study.
    Wei M; Wei J; Huang S · Journal of health, population, and nutrition · 2025
    Cross-sectional study11,520 participantsBone Health forCopper
  10. Association between dietary copper intake and bone mineral density in children and adolescents aged 8-19 years: A cross-sectional study.
    Cui A; Yan J; Li H; Fan Z; Wei X; Wang H; Zhuang Y · PloS one · 2024
    Cross-sectional study6,965 participantsBone Health forCopper
  11. Association between RBC folate and lumbar bone mineral density in postmenopausal women, a cross-sectional study from NHANES 2009-2018.
    Wei H; Jin Z; Zhou L; Tang G; Chai S; Che X; Tan Y; Zeng W · Frontiers in endocrinology · 2025
    Cross-sectional study1,315 participantsBone Health forFolate
  12. Genetic variants modify the associations of concentrations of methylmalonic acid, vitamin B-12, vitamin B-6, and folate with bone mineral density.
    Liu CT; Karasik D; Xu H; Zhou Y; Broe K; Cupples LA; Cpgm de Groot L; Ham A; Hannan MT; Hsu YH; Jacques P; McLean RR; Paul L; Selhub J; Trajanoska K; van der Velde N; van Schoor N; Kiel DP · The American journal of clinical nutrition · 2021
    Cohort study4,310 participantsBone Health forFolate
  13. Adequate Intake and Supplementation of B Vitamins, in Particular Folic Acid, can Play a Protective Role in Bone Health.
    Rondanelli M; Tartara A; Fossari F; Vecchio V; Faliva MA; Naso M; Perna S; Nichetti M; Peroni G · Current aging science · 2022
    Narrative review35,298 participants29 studies pooledBone Health forFolate Bone Health forVitamin B6
  14. Relation of homocysteine, folate, and vitamin B12 to bone mineral density of postmenopausal women.
    Cagnacci A; Baldassari F; Rivolta G; Arangino S; Volpe A · Bone · 2004
    Cross-sectional study161 participantsBone Health forFolate
  15. Dietary intake of folate, but not vitamin B2 or B12, is associated with increased bone mineral density 5 years after the menopause: results from a 10-year follow-up study in early postmenopausal women.
    Rejnmark L; Vestergaard P; Hermann AP; Brot C; Eiken P; Mosekilde L · Calcified tissue international · 2008
    Cohort study1,869 participantsBone Health forFolate
  16. Association between Serum Magnesium and Fractures: A Systematic Review and Meta-Analysis of Observational Studies.
    Dominguez LJ; Veronese N; Ciriminna S; Pérez-Albela JL; Vásquez-López VF; Rodas-Regalado S; Di Bella G; Parisi A; Tagliaferri F; Barbagallo M · Nutrients · 2023
    Meta-analysis119,755 participants4 studies pooledBone Health forMagnesium
  17. Bioabsorbable Magnesium-Based Materials Potential and Safety in Bone Surgery: A Systematic Review.
    Hung CH; Kwok YC; Yip J; Wong HH; Leung YY · Craniomaxillofacial trauma & reconstruction · 2025
    Systematic review386 participants8 studies pooledBone Health forMagnesium
  18. Vascularized bone grafting fixed by biodegradable magnesium screw for treating osteonecrosis of the femoral head.
    Zhao D; Huang S; Lu F; Wang B; Yang L; Qin L; Yang K; Li Y; Li W; Wang W; Tian S; Zhang X; Gao W; Wang Z; Zhang Y; Xie X; Wang J; Li J · Biomaterials · 2016
    Randomized trial48 participantsBone Health forMagnesium
  19. An update on magnesium and bone health.
    Rondanelli M; Faliva MA; Tartara A; Gasparri C; Perna S; Infantino V; Riva A; Petrangolini G; Peroni G · Biometals : an international journal on the role of metal ions in biology, biochemistry, and medicine · 2022
    Narrative reviewBone Health forMagnesium
  20. Sex-specific differences in the association of magnesium intake with femoral neck bone mineral density among older adults.
    Wang B; Tan X; Yao X; Zhu Z · Endocrine connections · 2025
    Cross-sectional study1,343 participantsBone Health forMagnesium