Glossary

Supplement NameAlso Known AsCategoryUse in ContextDescriptionHow It WorksBenefits (Short-term)Benefits (Long-term)Recommended Dosage (General)Recommended Dosage (By Age)Recommended Dosage (By Weight)Recommended Dosage (By Sex)TimingInteractions & ContraindicationsForms AvailableBioavailability TipsResearch HighlightsProduct Suggestions (Optional)
Magnesium GlycinateMagnesium BisglycinateMineralYoga, Pilates, Longevity, General HealthHighly bioavailable form of magnesium bound to glycine, known for calming effects.Supports over 300 enzymatic reactions; modulates NMDA receptors; improves muscle and nerve function.Reduces stress, improves sleep, eases muscle crampsSupports cardiovascular health, bone density, and long-term cognitive function200–400 mg/day20–40 yrs: 300 mg, 40–60 yrs: 350 mg, 60+ yrs: 400 mg~3–5 mg/kg body weightMen: up to 400 mg/day, Women: ~310–320 mg/dayEvening, 1–2 hours before bedAvoid with tetracycline antibiotics; separate from thyroid meds by 4 hoursCapsules, powders, effervescentsTake with meals; avoid calcium-heavy meals simultaneouslyJ Clin Sleep Med (2020): Improved sleep latency and qualityPure Encapsulations, Thorne, Doctor’s Best
AshwagandhaWithania somnifera, Indian GinsengAdaptogenYoga, Longevity, Stress ManagementAncient adaptogenic herb that helps the body resist stress and promote balance.Regulates cortisol levels; modulates GABAergic and serotonergic systems.Reduces anxiety, improves focus, mild energy boostImproved resilience, reduced cortisol, better hormonal balance300–600 mg/day of standardized extract20–60 yrs: ~300–600 mg/day, 60+ yrs: start with 300 mgApproximately 5–10 mg/kg body weightGenerally equal in both sexesMorning or early afternoon; avoid late nightMay potentiate sedatives or thyroid meds; avoid during pregnancyCapsules, powders, tincturesTake with fat for better absorptionJ Ethnopharmacol (2012): Improved anxiety and sleep in adultsKSM-66, Sensoril, Himalaya
Nicotinamide Mononucleotide (NMN)β-Nicotinamide mononucleotideLongevity CompoundLongevity, Cellular Energy, Anti-AgingNAD+ precursor that promotes cellular energy and DNA repair.Boosts NAD+ levels, activates sirtuins, supports mitochondrial healthIncreased energy, improved focus (in some users)Supports healthy aging, cellular repair, insulin sensitivity250–500 mg/day20–40 yrs: 250 mg/day, 40–60 yrs: 300–400 mg/day, 60+ yrs: 400–500 mg/day~4–6 mg/kgGenerally similar for men and womenMorning, ideally fastedAvoid with chemotherapy or autoimmune conditions unless supervisedCapsules, sublingual powderSublingual delivery improves bioavailabilityCell Metabolism (2016): Increased NAD+ in humansRenue by Science, DoNotAge, Elysium
Omega-3 Fatty AcidsEPA, DHA, Fish OilEssential Fatty AcidLongevity, Heart Health, Brain FunctionPolyunsaturated fats from marine sources that reduce inflammation.Reduces inflammatory markers, improves cell membrane fluidity, supports heart and brainImproved mood, reduced joint pain, clearer skinReduced cardiovascular risk, improved cognitive health1,000–2,000 mg combined EPA/DHA per day20–60 yrs: 1000–2000 mg, 60+ yrs: 1500–2500 mg~15–30 mg/kg EPA+DHAEqual for both sexesWith meals, preferably containing fatAvoid with blood thinners without medical adviceSoftgels, liquids, krill oil, algae oilTake with meals to improve absorptionJAMA (2018): Reduced cardiovascular events with long-term useNordic Naturals, Carlson, Viva Naturals
Coenzyme Q10 (CoQ10)Ubiquinone, UbiquinolAntioxidant, Mitochondrial NutrientLongevity, Heart Health, EnergyFat-soluble antioxidant crucial for mitochondrial ATP production.Supports mitochondrial energy production, reduces oxidative stressImproved stamina, reduced fatigueSupports cardiovascular health, protects against age-related decline100–200 mg/day40–60 yrs: 100 mg, 60+ yrs: up to 200 mg/day~1–2 mg/kgSame for men and womenMorning with a fat-containing mealMay interact with blood pressure or blood thinning medicationsSoftgels, capsules, liquidsTake with fat; ubiquinol form is better absorbedClin Interv Aging (2014): Improved endothelial function in elderlyKaneka Ubiquinol, Life Extension, NOW Foods
Nicotinamide Riboside (NR)Niagen, NRNAD+ PrecursorCellular Energy, LongevityA form of vitamin B3 that boosts NAD+ levels and supports mitochondrial health.Increases NAD+, supporting DNA repair and cellular metabolism.Enhanced energy, improved cellular function.May support metabolic health and longevity.250–500 mg/dayHigher doses often used in adults 40+~4–6 mg/kgSimilar for both sexesMorning on an empty stomachAvoid if undergoing chemotherapy; consult physicianCapsulesTake on empty stomachShown to increase NAD+ in humans (Cell Metabolism, 2016)Tru Niagen, Thorne
ResveratrolTrans-ResveratrolPolyphenolLongevity, Cardiovascular HealthA natural compound found in red grapes and berries, known for its antioxidant properties.Activates sirtuins and mimics caloric restriction effects.Improved endothelial function.Potential reduction in cardiovascular disease risk.100–500 mg/dayHigher doses may be considered for older adults.Approximately 1–5 mg/kgNo significant differences noted.With meals to enhance absorption.May interact with blood thinners.Capsules, tabletsCombine with piperine to enhance absorption.Studies suggest cardiovascular benefits and potential anti-aging effects.Biotivia, Thorne, Life Extension
CurcuminTurmeric ExtractPolyphenolAnti-inflammatory, Joint HealthThe active compound in turmeric, known for its anti-inflammatory effects.Inhibits NF-κB and other inflammatory pathways.Reduction in joint pain and inflammation.May support cognitive health and reduce chronic inflammation.500–2,000 mg/dayStandard dosing applies across age groups.Approximately 7–30 mg/kgNo significant differences noted.With meals to enhance absorption.May interact with anticoagulants.Capsules, powdersCombine with piperine to enhance absorption.Clinical trials support its anti-inflammatory and antioxidant effects.Meriva, Curamed, Doctor’s Best
Vitamin D3CholecalciferolVitaminBone Health, Immunity, MoodA fat-soluble vitamin essential for calcium metabolism and immune function.Regulates calcium absorption, modulates immune responses.Improves mood and immune readiness.Supports bone density, immune regulation, and reduces fall risk.1,000–4,000 IU/dayOlder adults may need closer to 2,000–4,000 IU/day~20–40 IU/kgEqual for both sexesWith meals (with fat)Avoid megadoses unless monitored; may interact with calciumSoftgels, drops, capsulesTake with fat for optimal absorptionSupports immune defense and bone metabolismNOW Foods, Thorne, Carlson
Taurine2-Aminoethanesulfonic AcidAmino Acid DerivativeCardiovascular Health, Energy, LongevityA conditionally essential amino acid involved in bile salt formation and cellular health.Regulates calcium signaling, antioxidant defenses, and mitochondrial function.Improves hydration, muscle function, and energy.Supports cardiovascular health, mitochondrial resilience, and lifespan (in animal studies).500–2,000 mg/dayAdults 40+ may benefit from higher end~10–30 mg/kgEqual dosing across sexesMorning or pre-exerciseGenerally safe; may affect blood pressure or insulin sensitivityCapsules, powdersCan be taken on empty stomach or with foodStudies show potential lifespan extension in animals (Science, 2023)Double Wood, Life Extension, Bulk Supplements
Urolithin AUAPostbiotic, Mitochondrial SupportCellular Energy, Longevity, Muscle FunctionA gut-derived metabolite that supports mitophagy and mitochondrial renewal.Stimulates mitophagy, enhancing mitochondrial quality control and function.May improve muscle endurance and energy.Supports mitochondrial health, muscle strength, and healthy aging.250–500 mg/dayOlder adults may benefit most from 500 mg/day~3–6 mg/kgEqual for both sexesMorning, with or without foodGenerally well tolerated; consult doctor if on mitochondrial-targeting medsCapsulesHighly bioavailable when formulated as MitopureShown to improve mitochondrial function in human trials (Nature Metabolism, 2020)Timeline Nutrition (Mitopure)
FisetinFlavonol FisetinSenolytic, FlavonoidSenescent Cell Clearance, InflammationA plant polyphenol with antioxidant and senolytic properties.Clears senescent cells and reduces pro-inflammatory signaling.Reduces inflammation, supports mood and cognition.Promotes healthy aging and cellular rejuvenation.100–500 mg/day; senolytic protocols may use 1,000 mg intermittentlyHigher intermittent doses in adults 40+~5–10 mg/kgEqual across sexesWith meals, short-term or pulsed useMay thin blood; consult with anticoagulant useCapsules, powdersUse with fat or liposomal formulations for better absorptionSenolytic effects shown in animal models and early human interest (EBioMedicine, 2018)Life Extension, Double Wood
Lithium (Low-Dose)Lithium Orotate (low dose)Trace MineralNeuroprotection, Mood Support, LongevityA trace element used in ultra-low doses for neuroprotection and mood balance.Modulates neurotransmitters and inhibits GSK-3 enzyme related to neurodegeneration.Improves mood stability and focus.May support brain aging and reduce neurodegeneration risk.1–5 mg/day elemental lithiumAdults 40+ may benefit most~0.03–0.07 mg/kgEqual for both sexesEvening, due to calming effectsAvoid high doses or use in bipolar disorder unless under supervisionCapsules (orotate form)Use low-dose lithium orotate; best with foodLinked to reduced dementia and suicide risk in population studies (JAMA Psychiatry, 2019)Advanced Research, Pure Encapsulations
SpermidinePolyamine SpermidineAutophagy EnhancerAutophagy, Cellular RenewalA naturally occurring polyamine that promotes autophagy and cellular renewal.Stimulates autophagy and regulates gene expression related to aging.Supports cellular detox and renewal.May enhance lifespan and healthspan.1–10 mg/day (typical supplements: 1–5 mg)40+ benefit most due to decreased natural levels~0.02–0.1 mg/kgEqual dosingWith meals, dailyGenerally safe; monitor if immune-suppressedCapsules, wheat germ extractTake with food containing healthy fatShown to increase lifespan in multiple organisms (Nature Cell Biology, 2016)SpermidineLIFE, Oxford Healthspan
Alpha-Ketoglutarate (AKG)AKG, Calcium AKGMetabolic IntermediateMitochondrial Support, Bone Health, LongevityA key component of the Krebs cycle involved in energy production and metabolic balance.Supports mitochondrial efficiency and reduces systemic inflammation.May improve energy and recovery.Shown to extend lifespan and reduce frailty in animal studies.1–2 g/day (as Calcium AKG)Adults 40+ often use 1,000–2,000 mg~10–20 mg/kgEqual for both sexesMorning with foodAvoid with chemotherapy unless cleared by doctorPowders, capsulesCalcium AKG form improves stability and uptakeIncreased lifespan and healthspan in mice (Cell Metabolism, 2020)Ponce de Leon, DoNotAge
Glucosamine SulfateGlucosamineJoint Support CompoundJoint Health, Cartilage RepairA natural compound that supports joint lubrication and cartilage regeneration.Stimulates cartilage matrix formation and reduces joint inflammation.Reduces joint pain and stiffness.May slow osteoarthritis progression and improve joint mobility.1,500 mg/dayOlder adults benefit most for osteoarthritis~20–25 mg/kgUsed similarly by both sexesWith mealsMay interact with blood thinners; shellfish allergy warningCapsules, powdersSulfate form better studied than hydrochlorideShown to support joint structure and reduce degenerationNOW Foods, Doctor’s Best, Schiff
Rhodiola RoseaGolden Root, Arctic RootAdaptogenLongevity, Stress Management, Cognitive FunctionA traditional herb used to combat fatigue and enhance mental performance.Modulates stress response by influencing cortisol levels and neurotransmitter activity.Reduces fatigue and improves focus.Enhances resilience to stress and supports mental clarity.200–600 mg/dayAdjust based on individual response and health status.Approximately 3–9 mg/kgNo significant differences noted.Morning or early afternoon to avoid potential sleep disturbances.May interact with antidepressants; consult healthcare provider if on medication.Capsules, tablets, tincturesStandardized extracts (e.g., SHR-5) may offer consistent potency.Studies suggest benefits in reducing stress and enhancing cognitive function.Gaia Herbs, Himalaya, NOW Foods
L-Theanineγ-GlutamylethylamideAmino AcidRelaxation, Cognitive Enhancement, Sleep SupportAn amino acid found in tea leaves, known for promoting relaxation without drowsiness.Increases alpha brain wave activity and modulates neurotransmitters like GABA and dopamine.Reduces stress and anxiety.Supports cognitive performance and sleep quality.100–400 mg/dayStandard dosing applies across age groups.Approximately 1.5–6 mg/kgNo significant differences noted.30–60 minutes before desired effect (e.g., relaxation or sleep).Generally safe; consult healthcare provider if on medication.Capsules, tablets, teasCan be taken with or without food.Studies indicate benefits in reducing stress and improving attention.Suntheanine, NOW Foods, Doctor’s Best
GABAGamma-Aminobutyric AcidNeurotransmitter SupplementRelaxation, Sleep, Anxiety ReductionA naturally occurring amino acid that functions as an inhibitory neurotransmitter in the brain.Promotes calmness by reducing neuronal excitability throughout the nervous system.Improves relaxation, reduces anxiety, supports better sleep.May support long-term stress reduction and emotional resilience.100–500 mg/dayAdjust for older adults based on sensitivity and sleep needs.1–6 mg/kg body weightGenerally similar for men and women.30 minutes before bed or during periods of high stress.May interact with benzodiazepines or sedatives; avoid alcohol.Capsules, powders, chewablesPharmaGABA form may offer better absorption and effectiveness.Some clinical support for sleep enhancement and mood regulation.Natural Factors PharmaGABA, NOW Foods
Lion’s Mane MushroomHericium erinaceusNootropic MushroomCognitive Function, NeuroprotectionA medicinal mushroom known for enhancing memory, focus, and nerve regeneration.Stimulates NGF (nerve growth factor) production in the brain.May improve clarity, focus, and reduce mild anxiety.Supports brain health, may reduce cognitive decline.500–1,000 mg 1–2x/dayLower doses for younger adults; higher doses in aging populations.Approx. 7–15 mg/kgEqual across sexes.Morning or midday for cognitive support.Generally safe; consult with doctor if on immunosuppressants.Capsules, powders, extractsDual-extracted (alcohol + water) forms are more potent.Studies show support for neurogenesis and memory improvement.Host Defense, Real Mushrooms, Om Mushroom Superfood
Chaga MushroomInonotus obliquusMedicinal MushroomImmune Support, Antioxidant, General HealthA nutrient-dense mushroom with high antioxidant capacity used in traditional medicine.Supports immune function and reduces oxidative stress through high polyphenol content.May boost immune resilience and reduce inflammation.May protect against oxidative stress and support cellular health.500–1,000 mg/dayStandard adult dose applies broadly.~6–15 mg/kgGenerally equal for both sexes.Morning or midday with food.May affect blood sugar and clotting; consult healthcare provider if diabetic or on anticoagulants.Powder, capsules, tea, tinctureDual-extracted (water and alcohol) for full benefits.Animal studies suggest immune and antioxidant support.Host Defense, Four Sigmatic, Real Mushrooms
Holy Basil (Tulsi)Ocimum sanctum, TulsiAdaptogenic HerbStress Relief, Immune Modulation, Hormonal BalanceA revered herb in Ayurvedic medicine known for promoting balance and stress resilience.Reduces cortisol, modulates inflammation and immune signaling.Eases anxiety, supports mood and focus.Supports hormonal balance, liver detoxification, and immune health.300–600 mg/dayAdults: 300–600 mg/day; dose may be reduced for sensitive individuals.~4–8 mg/kgNo known significant difference.Morning or with meals for calming effects.May lower blood sugar and interact with thyroid meds.Capsules, tea, tinctureUse standardized extracts (e.g., Ursolic acid content).Studies confirm stress and blood sugar regulation benefits.Organic India, Himalaya, Gaia Herbs
Bacopa MonnieriWater Hyssop, BrahmiAdaptogen, Nootropic HerbMemory, Focus, Cognitive AgingAn Ayurvedic herb used for centuries to enhance memory, learning, and brain function.Enhances synaptic communication, antioxidant protection, and neuroplasticity.Improves recall, reduces anxiety, enhances focus.May support memory retention and cognitive resilience in aging.300–600 mg/day of standardized extractLower doses for younger adults; seniors may benefit from full dose.~5–10 mg/kgNo known sex-based differences.Morning or early afternoon; may cause vivid dreams if taken late.May potentiate thyroid meds or sedatives.Capsules, tablets, powdersUse standardized extract (e.g., 20% bacosides); take with fat.Shown to improve cognition and reduce anxiety in clinical trials.Bacognize, Himalaya, Organic India
Creatine MonohydrateCreatineErgogenic AidStrength, Brain Health, Muscle RecoveryNaturally occurring compound that recycles ATP for quick energy; supports muscle and brain function.Replenishes phosphocreatine stores in muscles and brain.Improves strength, power, and exercise recovery.Supports muscle mass maintenance and cognitive health with age.3–5 g/dayOlder adults: 5 g/day; younger adults: 3–5 g/day~0.05 g/kgDosing consistent across sexes; may benefit women post-menopause.Post-workout or with meals for absorption boost.Generally safe; consult physician if kidney issues present.Powder, capsulesTake with carbohydrates to enhance uptake.Extensively studied for performance and neuroprotective benefits.Creapure, Optimum Nutrition, Bulk Supplements
Collagen PeptidesHydrolyzed Collagen, Collagen HydrolysateStructural ProteinJoint Health, Skin Health, RecoveryA protein that supports skin, joints, tendons, and bones; often used to promote recovery and tissue repair.Provides amino acids like glycine and proline necessary for collagen synthesis.May reduce joint pain and improve skin hydration.Supports skin elasticity, bone density, and joint resilience.10–15 g/dayOlder adults may require higher intake (15 g/day)~0.15–0.25 g/kgSame across sexesAny time; may be ideal post-workout or with vitamin CGenerally safe; monitor for allergies to source (e.g., bovine, marine)Powder, capsules, ready-to-drinkHydrolyzed peptides have better absorptionShown to improve skin elasticity and reduce joint discomfortVital Proteins, Great Lakes, Sports Research
Vitamin CAscorbic AcidVitamin, AntioxidantImmunity, Skin, RecoveryEssential antioxidant vitamin that supports collagen synthesis and immune health.Acts as a cofactor in enzymatic reactions and neutralizes free radicals.Supports immunity and reduces fatigue.Enhances collagen formation, antioxidant defense, and skin health.500–1,000 mg/dayAdults: 500–1,000 mg; elderly: up to 2,000 mg~7–15 mg/kgNo major difference; pregnant women may need moreWith meals or post-workoutHigh doses may cause GI upset; caution in kidney stone historyTablets, powders, liposomal, effervescentLiposomal or buffered forms may improve absorptionSupports immune defense and reduces duration of coldsLypo-Spheric, NOW Foods, Emergen-C
CalciumCalcium Carbonate, Calcium CitrateMineralBone Health, Muscle FunctionA vital mineral for bone density, nerve signaling, and muscle contractions.Supports skeletal mineralization and neuromuscular communication.Supports muscle function and bone strength.Helps prevent osteoporosis and maintains skeletal integrity.1,000–1,200 mg/day50+: 1,200 mg/day; 19–50: 1,000 mg/day~10–15 mg/kgPostmenopausal women and elderly men may need moreWith meals; split doses for best absorptionMay interfere with iron and magnesium absorptionTablets, capsules, chewablesCitrate form better for those with low stomach acidEssential role in bone mineral density maintenanceCitracal, NOW Foods, Nature Made
Glucosamine & ChondroitinGlucosamine Sulfate, Chondroitin SulfateJoint Health SupportJoint Flexibility, Cartilage HealthNaturally occurring compounds that help build and maintain cartilage.Reduce inflammation and support cartilage synthesis.Eases joint pain and stiffness.May slow joint degeneration and support mobility.1,500 mg Glucosamine + 1,200 mg Chondroitin dailyOlder adults often benefit more significantly~20–30 mg/kg combinedUsed similarly by all sexesWith mealsMay interact with blood thinners; caution in shellfish allergyCapsules, tablets, powdersSulfate form preferred for effectivenessMay reduce osteoarthritis symptoms over timeMove Free, Doctor’s Best, NOW Foods
ProbioticsLactobacillus, Bifidobacterium, AcidophilusMicrobial SupplementGut Health, Immunity, Mood RegulationLive beneficial bacteria that support gut microbiome and immune balance.Compete with harmful bacteria and modulate gut-brain-immune axis.Improved digestion, reduced bloating.Enhanced immunity, mood regulation, and gut microbiome diversity.5–50 billion CFU/dayLower doses for children and seniors; adults: 10–30 billion CFUNot typically weight-based; follow labelSpecific strains may benefit women (e.g., vaginal flora)On an empty stomach or with prebiotic fiberAvoid during acute illness unless supervised; caution with immunosuppressionCapsules, powders, fermented drinksEnteric-coated or spore-forming strains survive stomach acid betterClinical support for IBS, mood, immunity, and digestionSeed, Garden of Life, Culturelle
ElectrolytesSodium, Potassium, Magnesium, ChlorideHydration & Mineral SupportHydration, Muscle Function, Nerve SignalingMinerals that regulate fluid balance, muscle contractions, and nerve impulses.Maintain osmotic balance, nerve transmission, and muscle coordination.Replenishes hydration and reduces cramping.Supports cardiovascular health and neuromuscular function.Depends on activity; e.g., 500–1,000 mg sodium/day in active individualsAdults: maintain based on fluid loss; older adults may require monitoring~20–40 mg/kg total across all electrolytesSimilar needs; varies more by activity and environmentBefore, during, or after physical activityCaution in kidney or heart disease; sodium-sensitive hypertensionPowders, tablets, drink mixesBalanced blends with glucose improve absorptionEssential for hydration and athletic performanceLMNT, Nuun, Liquid I.V.
Protein PowdersWhey Protein, Casein, Pea Protein, Rice ProteinMacronutrient SupplementMuscle Recovery, Strength, SatietyConcentrated source of dietary protein used to support muscle repair and growth.Provides essential amino acids needed for protein synthesis and recovery.Promotes muscle recovery and reduces post-exercise soreness.Supports muscle maintenance, metabolic health, and lean body mass.20–40 g/day depending on dietary intakeSeniors may need higher intake (~1.2–1.6 g/kg/day total)~0.25–0.4 g/kg per servingDosage based on weight/activity, not sexPost-workout or as a meal/snack replacementCheck for allergens (dairy, soy); excess can stress kidneys in at-risk individualsPowders, ready-to-drink shakes, barsWhey isolate absorbs quickly; casein digests slowlyShown to increase muscle protein synthesis and support lean massOptimum Nutrition, Vega, Garden of Life
MultivitaminsDaily Vitamin, Complete FormulaMicronutrient BlendGeneral Health, Nutritional InsuranceCombination of essential vitamins and minerals designed to fill dietary gaps.Supports enzymatic reactions, immunity, and tissue repair by providing coenzymes and cofactors.Improves nutrient status and energy levels.May support longevity, immunity, and metabolic health.1 tablet or capsule/day or as directed on label50+: formulas with more B12, D, and calciumGenerally not weight-based; follow labelMen’s vs Women’s formulas differ in iron and calcium contentWith food, preferably breakfast or lunchAvoid high iron unless needed; excess vitamin A can be toxicTablets, capsules, gummies, powdersWhole-food-based or methylated forms offer better absorptionMixed results in studies; beneficial for deficiency preventionThorne, Garden of Life, MegaFood
ZincZinc Picolinate, Zinc Gluconate, Zinc CitrateMineralImmunity, Skin Health, Hormonal SupportEssential trace mineral involved in over 300 enzymatic reactions including immune and hormone function.Supports cellular immunity, antioxidant defense, and wound healing.Boosts immune function, supports skin healing.Promotes hormone balance, skin health, and resilience to infections.15–30 mg/dayAdults: 15 mg; Elderly: 20–30 mg~0.25–0.5 mg/kgMen may require more due to testosterone supportWith meals to avoid nauseaAvoid high doses long term; competes with copper absorptionCapsules, lozenges, tabletsPicolinate and citrate forms absorb wellSupports immune defense, testosterone, and wound healingNOW Foods, Thorne, Life Extension
SeleniumSelenomethionine, Sodium SeleniteTrace MineralThyroid Health, Antioxidant DefenseAn essential mineral that supports antioxidant enzymes and thyroid hormone metabolism.Component of glutathione peroxidase, protects cells from oxidative damage.Supports metabolism and immune balance.Protects against oxidative stress and supports thyroid function.100–200 mcg/daySame across adult groups; upper limit ~400 mcg/day~1.5–3 mcg/kgEqual for men and womenWith mealsToxic in high doses; avoid long-term mega-dosingCapsules, tabletsSelenomethionine form is best absorbedLinked to thyroid health and antioxidant protectionThorne, Pure Encapsulations, Life Extension
IronFerrous Sulfate, Ferrous Gluconate, Heme IronMineralEnergy, Oxygen Transport, Anemia PreventionEssential mineral required for hemoglobin production and cellular oxygen delivery.Supports red blood cell function and oxygenation of tissues.Improves energy, focus, and reduces fatigue if deficient.Prevents anemia, supports endurance and cognitive function.18 mg/day (adult women); 8 mg/day (men); therapeutic: 30–60 mg/dayTeens & menstruating women may need more; 50+ less unless deficient~1–2 mg/kg in therapeutic contextsHigher for menstruating women; men need lessEmpty stomach (if tolerated), or with vitamin CAvoid with calcium or caffeine; may cause GI upsetTablets, capsules, liquidVitamin C enhances absorption; heme iron is more bioavailableEssential for preventing iron-deficiency anemia and fatigueFeosol, MegaFood Blood Builder, Garden of Life
Vitamin B12Cobalamin, Methylcobalamin, CyanocobalaminVitaminEnergy, Brain Health, Red Blood Cell FormationWater-soluble B-vitamin essential for nerve function and DNA synthesis.Supports methylation, red blood cell production, and neurological integrity.Improves energy and mental clarity in deficiency.Prevents nerve damage and supports cognitive aging.250–500 mcg/day; 1,000 mcg for deficiencyHigher needs in seniors due to poor absorption~3–5 mcg/kgSimilar needs; pregnant women may need moreMorning; best on an empty stomachNo major issues; safe even at high dosesTablets, sublingual, injections, lozengesMethylcobalamin or sublingual forms absorb betterProtective in elderly against cognitive declineJarrow, Solgar, Thorne
FolateVitamin B9, Folic Acid, 5-MTHFVitaminCell Division, Methylation, Pregnancy SupportA B-vitamin essential for DNA synthesis, red blood cell formation, and methylation.Supports nucleotide production and homocysteine metabolism.Improves energy and cellular repair in deficiency.Prevents neural tube defects and supports brain health.400–800 mcg/dayAdults: 400 mcg; Pregnancy: 600–800 mcg~6–12 mcg/kgWomen of childbearing age need higher levelsWith mealsExcessive folic acid can mask B12 deficiencyTablets, capsules, multivitamins5-MTHF (methylfolate) form better for MTHFR gene variantsSupports brain health, pregnancy, and cardiovascular functionThorne, Pure Encapsulations, Designs for Health
Vitamin K2Menaquinone, MK-4, MK-7VitaminBone Health, Cardiovascular HealthFat-soluble vitamin important for calcium regulation and bone mineralization.Activates osteocalcin and matrix Gla-protein to direct calcium to bones.Supports bone strength and calcium balance.Reduces arterial calcification and supports heart health.90–200 mcg/dayAdults over 50 may need closer to 200 mcg/day~1.5–3 mcg/kgEqual for men and womenWith a fat-containing mealMay interact with blood thinners (e.g., warfarin)Capsules, tablets, softgelsMK-7 form has longer half-life and better absorptionShown to improve arterial flexibility and bone densityLife Extension, Sports Research, Thorne
Green Tea ExtractEGCG, Camellia sinensis extractPolyphenol, AntioxidantFat Loss, Antioxidant Support, Brain HealthConcentrated source of catechins, especially EGCG, with strong antioxidant activity.Inhibits COMT enzyme and boosts thermogenesis and cellular defense.May enhance alertness and fat metabolism.Supports cardiovascular and metabolic health.250–500 mg/day (standardized to EGCG)Similar for most adults; avoid high doses in elderly with liver sensitivity~4–8 mg/kgNo major differencesMorning or before mealsAvoid on empty stomach; may irritate liver in high dosesCapsules, powders, teasDivide dose throughout day; combine with black pepper extractWell-documented metabolic and cardiovascular benefitsLife Extension, NOW Foods, Jarrow Formulas
Fiber SupplementsPsyllium Husk, Inulin, Acacia Fiber, PrebioticsDigestive SupportDigestive Health, Blood Sugar, SatietyNon-digestible carbohydrates that support bowel regularity and gut health.Increases stool bulk, feeds beneficial gut bacteria, slows glucose absorption.Improves digestion, supports bowel regularity.Supports cardiovascular health, blood sugar control, and microbiome balance.5–15 g/dayYounger adults: 5–10 g; Older adults: 10–15 g~0.15–0.3 g/kgSlightly higher intake for men due to calorie needsWith water, ideally before mealsMay interfere with medication absorption if taken simultaneouslyPowders, capsules, barsEnsure adequate hydration to avoid bloatingSupports cholesterol, glucose regulation, and bowel regularityMetamucil, Benefiber, Heather’s Tummy Fiber