Micronutrients don't build muscle or burn fat directly — but they govern the processes that do. Energy production, protein synthesis, hormonal function, bone health, immune response, recovery — every one of these depends on an adequate supply of vitamins and minerals. Deficiencies are often silent for months before symptoms appear, which is why most people don't connect how they feel to what they're missing.
RDAs (Recommended Daily Allowances) below are the standard adult values from NIH/USDA. Active individuals often need more than the general population RDA, particularly for the nutrients flagged as training priorities.
Gold border = Training priority — particularly important for active people and body composition
Standard border = Comprehensive coverage — important but lower training specificity
Stored in Body Fat & Liver
Fat-Soluble Vitamins
Fat-soluble vitamins (A, D, E, K) are absorbed with dietary fat and stored in the body. They don't need to be consumed daily — but toxicity from over-supplementation is possible. Take with a meal containing fat for best absorption.
Vitamin D3
Cholecalciferol · The Sunshine Vitamin
Training Priority
Fat-Soluble
Function
Regulates calcium and phosphorus absorption for bone health. Supports immune function, muscle contraction, testosterone production, mood regulation, and insulin sensitivity. Acts more like a hormone than a vitamin — receptors exist in nearly every cell in the body.
Sources
Sunlight (primary), fatty fish (salmon, mackerel, sardines), egg yolks, beef liver, fortified dairy and plant milks. Dietary sources alone are rarely sufficient.
Deficiency
Fatigue, low mood, muscle weakness, increased injury risk, poor immune function, reduced testosterone, bone pain. Deficiency is extremely common — estimated 40%+ of adults in lower-sunlight countries.
Note
Most researchers consider the RDA significantly too low for optimal health. 2,000–4,000 IU daily is commonly recommended for active adults, particularly in winter months. Best taken with Vitamin K2 to direct calcium to bones rather than arteries.
Vitamin K2
Menaquinone · The Calcium Director
Training Priority
Fat-Soluble
Function
Activates proteins that direct calcium into bones and teeth — and away from arteries and soft tissue. Works synergistically with Vitamin D3. Critical for bone health, cardiovascular health, and proper calcium metabolism.
Sources
Natto (fermented soy — highest source by far), hard cheeses, egg yolks, dark chicken meat, butter from grass-fed cows, fermented vegetables.
Deficiency
Poor bone mineralisation, increased arterial calcification risk, easy bruising. Often deficient in people supplementing Vitamin D3 without K2.
Note
MK-7 form (from natto) has a longer half-life than MK-4 and is preferred for supplementation. If supplementing D3, pair with 100–200mcg K2 (MK-7).
Vitamin A
Retinol / Beta-Carotene
Function
Essential for vision (particularly night vision), immune function, skin and cell health, and gene expression. Supports protein synthesis and plays a role in testosterone production.
Sources
Beef liver (exceptionally high), salmon, eggs, dairy. Beta-carotene (converted to Vitamin A): sweet potato, carrots, spinach, kale, butternut squash.
Deficiency
Night blindness, dry skin, increased susceptibility to infection, impaired wound healing. Rare in developed countries with varied diets.
Note
Toxicity is possible from retinol (animal-source) supplements — not from beta-carotene. Avoid high-dose retinol supplementation unless medically indicated.
Vitamin E
Tocopherol · Antioxidant Vitamin
Function
Powerful fat-soluble antioxidant. Protects cell membranes from oxidative damage. Supports immune function, skin health, and vascular health. Assists Vitamin K function.
Sources
Sunflower seeds, almonds, hazelnuts, wheat germ oil, sunflower oil, pine nuts, peanut butter, avocado, spinach.
Deficiency
Rare in healthy adults. Can cause nerve and muscle damage, weakened immune response, and vision problems when severely deficient. More common in people with fat malabsorption conditions.
Note
High-dose supplementation (400 IU+) may actually blunt some beneficial training adaptations by reducing exercise-induced oxidative stress. Food sources are preferred over supplements.
Vitamin K1
Phylloquinone · Clotting Vitamin
Function
Essential for blood clotting — activates clotting factors in the liver. Also contributes to bone metabolism, though K2 is more active in this role. Works alongside K2 in overall Vitamin K function.
Sources
Kale, spinach, collard greens, Swiss chard, broccoli, Brussels sprouts, parsley, green onions. Leafy greens are the primary source.
Deficiency
Impaired blood clotting, easy bruising and bleeding, poor wound healing. Rare in adults eating leafy greens regularly.
Note
If taking blood-thinning medications (warfarin), Vitamin K intake needs to be consistent — not necessarily restricted, but stable. Consult your doctor.
Not Stored — Require Daily Intake
Water-Soluble Vitamins
Water-soluble vitamins (C and the B-complex) are not stored in significant amounts — excess is excreted in urine. This means toxicity is rare, but regular intake through food or supplementation is essential. Active individuals deplete B vitamins faster due to increased energy metabolism.
Vitamin C
Ascorbic Acid · Immune & Collagen Vitamin
Training Priority
Water-Soluble
Function
Essential for collagen synthesis — the protein that forms connective tissue, tendons, ligaments, and cartilage. Powerful antioxidant. Enhances iron absorption from plant sources. Supports immune function and wound healing. Reduces exercise-induced oxidative stress.
Sources
Bell peppers (red highest), kiwi fruit, strawberries, citrus fruits, broccoli, Brussels sprouts, papaya, guava. Destroyed by heat — raw sources retain more.
Deficiency
Fatigue, poor wound healing, joint pain, frequent illness, easy bruising. Severe deficiency causes scurvy — rare but possible in highly restricted diets.
Note
Active adults and smokers may benefit from 500–1,000mg daily. Pair with iron-rich plant foods to significantly enhance iron absorption. High doses above 2,000mg/day can cause digestive upset.
Vitamin B12
Cobalamin · Energy & Nerve Vitamin
Training Priority
Water-Soluble
Function
Essential for red blood cell formation, DNA synthesis, neurological function, and energy metabolism. Supports myelin sheath integrity — the protective coating of nerves. Critical for converting food into usable energy.
Sources
Almost exclusively animal products: beef liver (exceptional source), clams, oysters, sardines, salmon, beef, eggs, dairy, nutritional yeast (fortified). Vegans and vegetarians must supplement.
Deficiency
Fatigue, weakness, brain fog, poor memory, tingling or numbness in extremities, mood changes, anaemia. Deficiency develops slowly — stores can last 2–5 years — making it easy to miss until significant.
Note
Methylcobalamin form is better absorbed than cyanocobalamin. Non-negotiable supplement for vegans and vegetarians. Absorption declines with age — adults over 50 are at higher risk of deficiency regardless of diet.
Vitamin B9
Folate / Folic Acid · Cell Division Vitamin
Training Priority
Water-Soluble
Function
Essential for DNA synthesis and repair, red blood cell formation, and cell division — making it critical during periods of rapid growth and recovery. Supports amino acid metabolism. Particularly important for women of childbearing age.
Sources
Beef liver, dark leafy greens (spinach, asparagus, Brussels sprouts), legumes (lentils, chickpeas, black beans), avocado, eggs, fortified cereals and grains.
Deficiency
Anaemia, fatigue, poor recovery, mouth sores, neural tube defects during pregnancy. Megaloblastic anaemia produces large, dysfunctional red blood cells that carry less oxygen — directly impacting training performance.
Note
Methylfolate (5-MTHF) is the active form and preferred for supplementation — particularly for those with the MTHFR gene variant who cannot efficiently convert folic acid. 600mcg recommended during pregnancy.
Vitamin B6
Pyridoxine · Metabolism & Brain Vitamin
Training Priority
Water-Soluble
Function
Involved in over 100 enzyme reactions — primarily in amino acid and protein metabolism. Supports neurotransmitter synthesis (serotonin, dopamine, GABA), immune function, haemoglobin production, and glycogen breakdown for energy during exercise.
Sources
Tuna, salmon, chicken breast, turkey, beef liver, potatoes, bananas, chickpeas, sunflower seeds, pistachios, fortified cereals.
Deficiency
Anaemia, dermatitis, weakened immunity, depression, confusion, peripheral neuropathy. Linked to poor mood and irritability at subclinical levels.
Note
Needs increase with high protein diets — B6 is required to metabolise amino acids. Long-term high-dose supplementation (above 100mg/day) can cause nerve damage.
Vitamin B1
Thiamine · Energy Unlock Vitamin
Function
Converts carbohydrates into usable energy (ATP). Essential for glucose metabolism, nerve function, and muscle contraction. Required for the Krebs cycle — the primary energy-production pathway during exercise.
Sources
Pork loin, trout, macadamia nuts, black beans, edamame, sunflower seeds, green peas, fortified cereals and grains, whole grain bread.
Deficiency
Fatigue, muscle weakness, poor coordination, nerve damage, heart problems. Severe deficiency causes beriberi. Alcohol consumption significantly impairs B1 absorption and increases risk of deficiency.
Vitamin B2
Riboflavin · Cellular Energy Vitamin
Function
Key component of FAD and FMN coenzymes — essential for cellular energy production from carbohydrates, fats, and proteins. Supports antioxidant function, iron metabolism, and B6 and folate activation.
Sources
Beef liver, clams, dairy products (milk, yoghurt), eggs, lean beef, chicken, almonds, mushrooms, fortified cereals. Destroyed by light — store milk in opaque containers.
Deficiency
Cracked lips and corners of mouth, sore throat, inflammation of mouth and tongue, anaemia, skin disorders. Rare with varied diet.
Vitamin B3
Niacin · NAD Precursor
Training Priority
Water-Soluble
Function
Precursor to NAD+ and NADP+ — coenzymes involved in hundreds of metabolic reactions including energy production, DNA repair, and cellular signalling. NAD+ declines with age and is critical for mitochondrial function and longevity pathways.
Sources
Chicken breast, turkey, beef liver, tuna, salmon, pork loin, peanuts, sunflower seeds, mushrooms, fortified cereals. Also synthesised from tryptophan in the body.
Deficiency
Pellagra (rare in developed countries): dermatitis, diarrhoea, dementia. Subclinical deficiency causes fatigue, poor recovery, and reduced cognitive function.
Note
High-dose niacin (1,000mg+) causes flushing and is used medically for cholesterol management. NMN and NR supplements are NAD+ precursors with emerging research for performance and longevity.
Vitamin B5
Pantothenic Acid · Hormone & CoA Vitamin
Function
Required for synthesis of Coenzyme A — essential for fatty acid metabolism, carbohydrate oxidation, and steroid hormone synthesis (including cortisol). Involved in haemoglobin synthesis and neurotransmitter production.
Sources
Beef liver, chicken, beef, mushrooms, sunflower seeds, avocado, sweet potato, lentils, eggs, dairy. Found widely in food — deficiency is rare.
Deficiency
Fatigue, irritability, numbness in hands and feet ("burning feet" syndrome), poor wound healing. Almost always paired with other B vitamin deficiencies.
Vitamin B7
Biotin · Metabolism & Hair Vitamin
Function
Coenzyme for carboxylase enzymes involved in fatty acid synthesis, gluconeogenesis, and amino acid metabolism. Supports healthy hair, skin, and nails — though this is often overstated by supplement marketing.
Sources
Beef liver, eggs (cooked — raw egg whites block biotin absorption), salmon, pork, sweet potato, sunflower seeds, almonds, cheese, avocado.
Deficiency
Hair thinning, brittle nails, skin rash, neurological symptoms. Rare — caused primarily by consuming large amounts of raw egg whites over extended periods.
Note
High-dose biotin supplements can interfere with thyroid and cardiac blood test results — inform your doctor if taking high doses before any blood work.
Required in Larger Amounts
Macrominerals
Macrominerals are required in amounts greater than 100mg per day. They form the structural basis of bones and teeth, regulate fluid balance, enable nerve transmission, and drive muscle contraction. Active individuals lose several of these through sweat and have higher requirements than sedentary populations.
Magnesium
The Recovery Mineral
Training Priority
Macromineral
Function
Cofactor in over 300 enzymatic reactions. Essential for ATP production, protein synthesis, muscle and nerve function, blood glucose control, and blood pressure regulation. Directly involved in muscle contraction and relaxation. Supports sleep quality by activating the parasympathetic nervous system.
Sources
Pumpkin seeds (highest), dark chocolate (70%+), almonds, cashews, spinach, black beans, edamame, avocado, whole grains, salmon, chicken breast.
Deficiency
Muscle cramps and twitches, poor sleep quality, fatigue, anxiety, elevated blood pressure, poor recovery, constipation, headaches. Estimated 50–60% of active adults are deficient — lost significantly through sweat.
Note
Glycinate form is best for sleep and recovery (gentle, well-absorbed). Malate for energy. Citrate for constipation. Oxide has poor absorption — avoid in supplements. Take 200–400mg before bed.
Calcium
The Structural Mineral
Training Priority
Macromineral
Function
Forms bones and teeth (99% of body calcium is stored here). Essential for muscle contraction — including the heart. Involved in nerve transmission, blood clotting, enzyme activation, and hormone secretion. Muscle cannot contract without adequate calcium.
Sources
Dairy products (milk, yoghurt, cheese — highest bioavailability), sardines and canned salmon with bones, tofu made with calcium sulphate, fortified plant milks, kale, bok choy, broccoli.
Deficiency
Short-term: muscle cramps, numbness, poor blood clotting. Long-term: osteopenia and osteoporosis — bones become progressively weaker and fracture-prone. Often symptomless until significant bone loss has occurred.
Note
Calcium competes with iron and magnesium for absorption — don't take all three together. Spread intake across the day rather than one large dose. Must be paired with Vitamin D3 and K2 for effective utilisation.
Potassium
The Electrolyte Mineral
Training Priority
Macromineral
Function
Primary intracellular electrolyte. Regulates fluid balance, nerve signals, muscle contractions, and heart rhythm. Works directly opposite sodium — critical for blood pressure regulation. Lost significantly through sweat during exercise.
Sources
Dried apricots, lentils, prunes, pumpkin, potato (with skin), kidney beans, orange juice, banana, avocado, spinach, salmon, chicken, beef.
Deficiency
Muscle weakness, cramps, fatigue, heart palpitations, constipation. Severe hypokalemia is dangerous — causes abnormal heart rhythms. Mild deficiency common in people with high sodium intake or significant sweat loss.
Note
Most adults fall significantly short of this target. Focus on whole food sources — high-dose potassium supplements can be dangerous without medical supervision.
Sodium
The Fluid Balance Mineral
Function
Primary extracellular electrolyte. Regulates fluid volume, blood pressure, and nerve and muscle function. Essential for nutrient absorption in the gut. Required for muscle contraction alongside potassium.
Sources
Table salt, processed and packaged foods (primary source in most diets), cured meats, cheese, bread, sauces, soups. Most people exceed requirements easily.
Deficiency
Hyponatraemia: headache, nausea, confusion, seizures in severe cases. Can occur in endurance athletes who drink excessive water without electrolyte replacement.
Note
Most people overconsume sodium — deficiency is rarely a concern unless training intensely in heat with high sweat output. The sodium:potassium ratio matters more than absolute sodium intake.
Phosphorus
The Energy Currency Mineral
Function
Second most abundant mineral in the body after calcium. Forms ATP — the universal energy currency. Critical component of DNA and RNA. Works with calcium to build bones and teeth. Involved in kidney function and pH regulation.
Sources
Dairy products, meat, poultry, fish, eggs, legumes, nuts, seeds, whole grains. Found abundantly in protein-rich foods — deficiency is rare in people meeting protein targets.
Deficiency
Muscle weakness, bone pain, fatigue, numbness. Rare in adults eating sufficient protein. More common with chronic antacid use, which blocks phosphorus absorption.
Chloride
Stomach Acid & Fluid Balance
Function
Primary component of hydrochloric acid in the stomach — essential for protein digestion and killing pathogens. Works with sodium to maintain fluid and electrolyte balance. Involved in nerve transmission and maintaining blood pH.
Sources
Table salt (sodium chloride), seaweed, olives, celery, rye, tomatoes. Consumed almost entirely alongside sodium in the diet.
Deficiency
Rare under normal dietary conditions. Muscle cramps, poor digestion, fatigue. Can occur with excessive vomiting, heavy sweating, or certain medical conditions.
Sulphur
Protein Structure Mineral
Function
Essential component of the amino acids methionine and cysteine — building blocks of all proteins. Required for synthesis of glutathione (the body's primary antioxidant), collagen, keratin, and connective tissue. Supports liver detoxification pathways.
Sources
Eggs, meat, poultry, fish, dairy, legumes, garlic, onions, Brussels sprouts, broccoli, cabbage, kale. Obtained naturally through protein intake.
Deficiency
Rare in people with adequate protein intake. Joint pain, weak nails and hair, poor skin condition, reduced antioxidant capacity. No established RDA.
Required in Smaller Amounts — No Less Important
Trace Minerals
Trace minerals are required in amounts less than 100mg per day, but their roles are critical. Many are involved in hormone production, antioxidant defence, and enzyme function. Deficiencies are surprisingly common despite small required amounts.
Training Priority
Trace Mineral
Function
Core component of haemoglobin — the protein that carries oxygen in red blood cells — and myoglobin, which stores oxygen in muscle tissue. Required for ATP production, immune function, collagen synthesis, and neurotransmitter production. Training performance is directly limited by iron status.
Sources
Haem iron (best absorbed): beef liver, red meat, dark turkey, oysters, sardines. Non-haem iron: lentils, spinach, tofu, pumpkin seeds, quinoa, fortified cereals — pair with Vitamin C to enhance absorption.
Deficiency
Fatigue, reduced exercise capacity, shortness of breath, pale skin, brain fog, cold hands and feet, frequent illness. Iron deficiency anaemia is the most common nutritional deficiency globally — disproportionately affects women who menstruate and endurance athletes.
RDA
8 mg (men) · 18 mg (women)
Note
Don't supplement iron without a blood test confirming deficiency — excess iron is harmful and pro-oxidant. Ferritin levels (iron stores) are the most useful indicator alongside serum iron. Coffee, tea, and calcium reduce absorption.
Zinc
The Hormone & Immune Mineral
Training Priority
Trace Mineral
Function
Involved in over 300 enzymatic reactions. Required for testosterone production, protein synthesis, wound healing, immune function, DNA synthesis, and cell division. Supports taste and smell. Lost through sweat — active individuals need more.
Sources
Oysters (highest source by far), beef, pork, crab, lobster, chicken (dark meat), pumpkin seeds, hemp seeds, cashews, chickpeas, lentils.
Deficiency
Impaired immune function, poor wound healing, hair loss, loss of taste and smell, reduced testosterone, skin problems, delayed recovery from training. Common in athletes and vegetarians.
RDA
8 mg (women) · 11 mg (men)
Note
Zinc picolinate or bisglycinate are the best-absorbed forms. High doses (above 40mg/day long-term) deplete copper — if supplementing zinc regularly, consider a copper supplement alongside. Zinc and iron compete for absorption — take separately.
Selenium
The Thyroid & Antioxidant Mineral
Training Priority
Trace Mineral
Function
Essential for thyroid hormone synthesis and metabolism — thyroid hormones regulate metabolism, energy, and body composition. Required for selenoprotein production, including glutathione peroxidase (key antioxidant enzyme). Supports immune function, reproductive health, and DNA synthesis.
Sources
Brazil nuts (just 1–2 per day meets requirements), tuna, halibut, sardines, oysters, beef liver, turkey, chicken, eggs, sunflower seeds, whole wheat bread.
Deficiency
Thyroid dysfunction, weakened immunity, increased oxidative stress, muscle weakness, poor recovery, reproductive problems. Soil selenium content varies widely — deficiency common in certain regions.
Note
Toxicity (selenosis) occurs above 400mcg/day — hair loss, nail brittleness, garlic breath, nerve damage. Brazil nuts are efficient but inconsistent in selenium content — 1–2 per day is sufficient. Don't mega-dose.
Iodine
The Thyroid Mineral
Function
Essential component of thyroid hormones T3 and T4 — which regulate metabolism, energy production, body temperature, growth, and development. Without adequate iodine, the thyroid cannot function properly.
Sources
Seaweed (nori, wakame, kelp — variable and sometimes very high), seafood, dairy products, eggs, iodised table salt. Content in plant foods depends on soil iodine levels.
Deficiency
Hypothyroidism symptoms: fatigue, weight gain, cold intolerance, dry skin, hair loss, slow metabolism, brain fog. Goitre (enlarged thyroid). Major public health concern globally — iodised salt was introduced specifically to address widespread deficiency.
Note
Both deficiency and excess are harmful to thyroid function. Those using non-iodised sea salt or pink himalayan salt exclusively and eating few dairy/seafood products are at risk. Vegans and those on low-salt diets should be mindful.
Copper
Iron's Partner Mineral
Function
Essential for iron metabolism — copper is required for iron to be incorporated into haemoglobin. Required for connective tissue formation, antioxidant enzyme production (superoxide dismutase), energy production, and neurotransmitter synthesis.
Sources
Beef liver, oysters, crab, lobster, dark chocolate (70%+), cashews, sunflower seeds, almonds, lentils, mushrooms, avocado, whole grains.
Deficiency
Anaemia (iron-resistant), fatigue, poor immune function, weak connective tissue, neurological problems. Can be caused by excessive zinc supplementation without copper balance.
Manganese
Bone & Antioxidant Mineral
Function
Cofactor for enzymes involved in bone formation, carbohydrate and fat metabolism, and antioxidant defence (manganese superoxide dismutase). Required for collagen synthesis and wound healing.
Sources
Mussels, hazelnuts, pecans, pine nuts, whole grains (oats, brown rice), pineapple, spinach, sweet potato, black beans, tofu, tea (brewed).
Deficiency
Poor bone health, impaired glucose tolerance, skin rash, poor wound healing. Rare — most balanced diets provide adequate amounts.
Chromium
Insulin Sensitivity Mineral
Function
Enhances the action of insulin — the hormone that regulates blood sugar and drives nutrients into cells. Involved in carbohydrate, fat, and protein metabolism. May support lean body mass preservation.
Sources
Broccoli (highest), grape juice, whole grain products, beef, turkey, potatoes, garlic, basil, orange juice. Content varies widely based on soil conditions.
Deficiency
Impaired glucose tolerance, elevated blood sugar, weight gain, increased cholesterol. Difficult to diagnose as no reliable biomarker exists for chromium status.
Fluoride
Dental & Bone Structure
Function
Strengthens tooth enamel and bones by incorporating into the crystalline structure of hydroxyapatite. Inhibits the bacteria responsible for dental cavities. Supports bone density at adequate levels.
Sources
Fluoridated drinking water (primary source in many countries), tea (naturally high), seafood, grape juice, potatoes. Most people meet requirements through water.
Deficiency
Increased dental cavities and tooth decay, weakened tooth enamel. Bone fractures at very low intake levels.
Molybdenum
Detoxification Mineral
Function
Cofactor for enzymes that process sulphur-containing amino acids and detoxify certain compounds in the liver. Involved in uric acid formation. Required for normal growth and development.
Sources
Legumes (black-eyed peas, lentils, lima beans — highest sources), whole grains, dairy, nuts, leafy vegetables. Content varies significantly by soil conditions.
Deficiency
Extremely rare in practice. Rapid heart and breathing rate, neurological symptoms in severe cases. Not a practical concern for most people eating legumes regularly.