Iron
Red meat and shellfish, Legumes, Fortified cereals, Leafy greens.
Back to TagsFatigue can come from sleep debt, anemia, thyroid disease, infection, depression, medication effects, under-eating, overtraining, or chronic disease. Treat this page as a map of related topics, not a cause finder.
Source mix: Official Reference, Government Health Agency, Academic Review, Traditional / Safety Reference. Iron Fact Sheet for Health Professionals Vitamin B12 Fact Sheet for Health Professionals Folate Fact Sheet for Health Professionals Magnesium Fact Sheet for Health Professionals Spilling the Beans: How Much Caffeine is Too Much? ISSN Position Stand: Caffeine and Exercise Performance ISSN Position Stand: Safety and Efficacy of Creatine Supplementation in Exercise, Sport, and Medicine Common Questions and Misconceptions About Creatine Supplementation Herbs at a Glance Mixing Medications and Dietary Supplements Can Endanger Your Health
Tag
Energy
Energy-related references connect nutrients and bioactives involved in oxygen transport, red blood cell formation, ATP metabolism, and stimulant or fatigue-related contexts.
fatiguetiredlow energymitochondriared blood cellsstaminaalertness
Linked Items
7
May Support
6
Deficiency Signs
0
Cautions
1
Quick Compare
| Item | Type | Relationship | Evidence |
|---|---|---|---|
| Iron | nutrient | May Support | Official nutrient-role framing from NIH ODS. Iron supplementation should be based on need because excess can be harmful. Official Reference |
| Vitamin B12 | nutrient | May Support | Official nutrient-role framing from NIH ODS. Official Reference |
| Folate | nutrient | May Support | Official nutrient-role framing from NIH ODS. Official Reference |
| Magnesium | nutrient | May Support | Official nutrient-role framing from NIH ODS. Official Reference |
| Caffeine | bioactive | May Support | FDA safety context and ISSN sports-performance evidence; tolerance, dose, and timing matter. Government Health Agency |
| Creatine | bioactive | May Support | ISSN position-stand evidence; most direct support is for strength, power, and repeated high-intensity exercise. Academic Review |
| Rhodiola | bioactive | Caution / Limited Evidence | Included from the botanical catalog as a review target; treat as emerging until claim-level sources are expanded. Traditional / Safety Reference |
Foods First
Vitamin B12
Meat and fish, Eggs and dairy foods, Fortified plant foods.
Folate
Leafy green vegetables, Legumes, Fortified grain products.
Magnesium
Nuts and seeds, Legumes, Whole grains, Leafy green vegetables.
Caffeine
Coffee, tea, yerba mate, guarana, cacao.
Creatine
Beef, pork, salmon, tuna, herring.
Rhodiola
Rhodiola rosea root.
Medication & Safety Cautions
Iron
Iron is required for hemoglobin and myoglobin, which support oxygen transport and muscle oxygen use. | Iron overdose can be dangerous, especially for children. High-dose use should be guided by a clinician.
Folate
Folate supports DNA synthesis and red blood cell formation, which connects it to anemia and fatigue contexts. | The UL applies to folic acid from supplements and fortified foods, not naturally occurring food folate.
Magnesium
Magnesium participates in energy production and normal muscle and nerve function. | The DRI UL applies to supplemental/pharmacological magnesium, not magnesium naturally present in food and water.
Caffeine
Caffeine can support alertness and exercise performance in some contexts. | pregnancy/breastfeeding | sleep | anxiety
Creatine
Creatine supports rapid ATP recycling, especially in high-intensity muscle and brain energy contexts. | kidney disease | pregnancy/breastfeeding | complex medical conditions
Rhodiola
Rhodiola is marketed for fatigue and stress resilience, but evidence is product- and outcome-specific and still needs deeper review in this app. | insomnia | anxiety | blood pressure medications
Key Studies & Fixed References
These are the dated references used for this tag. Live research searches can change; these links explain the fixed wording shown on this page.
NIH Office of Dietary Supplements | Acquired 2026-07-23 | Official Reference
Heme and non-heme iron, Iron supplement forms, Elemental iron context.
NIH Office of Dietary Supplements | Acquired 2026-07-23 | Official Reference
Cobalamin forms, B12 supplement forms, B12 absorption context.
NIH Office of Dietary Supplements | Acquired 2026-07-23 | Official Reference
Food folate, Folic acid, 5-MTHF.
NIH Office of Dietary Supplements | Acquired 2026-07-23 | Official Reference
Magnesium supplement forms, Magnesium bioavailability, Magnesium medication interactions.
U.S. Food and Drug Administration | Acquired 2026-07-23 | Government Health Agency
Caffeine safety-limit context.
Journal of the International Society of Sports Nutrition / PubMed | Acquired 2026-07-23 | Academic Review
Caffeine performance evidence, Caffeine dose and timing context.
Journal of the International Society of Sports Nutrition / PubMed | Acquired 2026-07-23 | Academic Review
Creatine performance, Creatine safety, Creatine studied dosing context.
Journal of the International Society of Sports Nutrition / PubMed | Acquired 2026-07-23 | Academic Review
Creatine safety myths, Creatine common dosing context.
National Center for Complementary and Integrative Health | Acquired 2026-07-23 | Traditional / Safety Reference
Botanical safety framing, Herb evidence summaries.
U.S. Food and Drug Administration | Acquired 2026-07-23 | Government Health Agency
Supplement-medication interaction warning language.
May Support
Iron
nutrientOfficial Reference
Iron is required for hemoglobin and myoglobin, which support oxygen transport and muscle oxygen use.
Evidence note: Official nutrient-role framing from NIH ODS. Iron supplementation should be based on need because excess can be harmful.
Sources: Iron Fact Sheet for Health Professionals (2026-07-23)Official Reference
Vitamin B12
nutrientOfficial Reference
Vitamin B12 supports red blood cell formation and neurologic function; deficiency can present with fatigue and neurologic symptoms.
Evidence note: Official nutrient-role framing from NIH ODS.
Sources: Vitamin B12 Fact Sheet for Health Professionals (2026-07-23)Official Reference
Folate
nutrientOfficial Reference
Folate supports DNA synthesis and red blood cell formation, which connects it to anemia and fatigue contexts.
Evidence note: Official nutrient-role framing from NIH ODS.
Sources: Folate Fact Sheet for Health Professionals (2026-07-23)Official Reference
Magnesium
nutrientOfficial Reference
Magnesium participates in energy production and normal muscle and nerve function.
Evidence note: Official nutrient-role framing from NIH ODS.
Sources: Magnesium Fact Sheet for Health Professionals (2026-07-23)Official Reference
Caffeine
bioactiveGovernment Health Agency
Caffeine can support alertness and exercise performance in some contexts.
Evidence note: FDA safety context and ISSN sports-performance evidence; tolerance, dose, and timing matter.
Sources: Spilling the Beans: How Much Caffeine is Too Much? (2026-07-23)Government Health Agency, ISSN Position Stand: Caffeine and Exercise Performance (2026-07-23)Academic Review
Creatine
bioactiveAcademic Review
Creatine supports rapid ATP recycling, especially in high-intensity muscle and brain energy contexts.
Evidence note: ISSN position-stand evidence; most direct support is for strength, power, and repeated high-intensity exercise.
Sources: ISSN Position Stand: Safety and Efficacy of Creatine Supplementation in Exercise, Sport, and Medicine (2026-07-23)Academic Review, Common Questions and Misconceptions About Creatine Supplementation (2026-07-23)Academic Review
Caution / Limited Evidence
Rhodiola
bioactiveTraditional / Safety Reference
Rhodiola is marketed for fatigue and stress resilience, but evidence is product- and outcome-specific and still needs deeper review in this app.
Evidence note: Included from the botanical catalog as a review target; treat as emerging until claim-level sources are expanded.
Sources: Herbs at a Glance (2026-07-23)Traditional / Safety Reference, Mixing Medications and Dietary Supplements Can Endanger Your Health (2026-07-23)Government Health Agency