The 15 Essential Minerals: Complete Guide to Functions, Sources, and Benefits

Minerals are inorganic nutrients that your body cannot make on its own — they must come from food, water, and, when needed, supplements. Like vitamins, they’re needed in relatively small amounts, but their roles in the body are anything but small. Minerals build bones and teeth, transmit nerve signals, contract muscles, form parts of hormones, transport oxygen, regulate fluid balance, and power hundreds of enzyme reactions.

Because minerals often work in close partnership — with each other and with vitamins — getting the full spectrum through a varied, whole-food diet matters. And for many minerals, the bigger modern risk is getting too much from supplements rather than too little from food, so this page lists both recommended intakes and upper limits.

This page covers the 15 minerals with official US intake recommendations, divided into two categories: macro-minerals (needed in larger amounts) and trace minerals, also called micro-minerals (needed in much smaller amounts). Two of them — fluoride and chromium — aren’t considered essential nutrients by European food safety authorities, as their pages explain.

For a broader overview of how minerals fit into complete nutrition, visit our Basic Nutrition page and Vitamins page.

Macro-Minerals vs. Trace Minerals

Macro-minerals are needed in amounts greater than 100mg per day. They have fundamental structural and physiological roles — bone formation, fluid balance, nerve and muscle function, and energy production.

Trace minerals (micro-minerals) are needed in amounts less than 100mg per day — often in microgram quantities. Despite the tiny amounts, they play critical roles as enzyme cofactors, as parts of antioxidant enzymes, and as components of hormones, such as iodine in thyroid hormones.

Macro-Minerals

1. Calcium

Calcium is the most abundant mineral in the human body — about 99% of it is stored in bones and teeth, where it provides structure and strength. The remaining 1% circulates in the blood and soft tissues, where it’s critical for muscle contraction, nerve signalling, hormone release, and blood clotting. Your body keeps blood calcium within a tight range — if your diet falls short, it draws calcium from your bones to maintain normal blood levels, gradually weakening them over time.

Key functions: Bone and tooth structure and strength, muscle contraction (including heart muscle), nerve signal transmission, blood clotting, hormone secretion, enzyme activation.

Deficiency symptoms: Low calcium intake is usually silent — the body takes what it needs from bone, leading over the years to bone loss (osteopenia and osteoporosis). Muscle cramps, tingling, and heart rhythm problems come from low blood calcium (hypocalcemia), which usually has medical causes — such as parathyroid or kidney problems, or severe vitamin D deficiency — rather than a low-calcium diet. Rickets in children is usually caused by vitamin D deficiency, though very low calcium intake can contribute.

Best food sources: Dairy products (milk, yogurt, cheese — the most concentrated well-absorbed sources), calcium-set tofu, sardines and canned salmon with bones, low-oxalate greens (kale, bok choy, broccoli), fortified plant milks and juices, almonds. Spinach contains calcium, but very little of it is absorbed.

Recommended daily intake: 1,000mg for most adults; 1,200mg for women over 50 and men over 70; 1,300mg for teenagers. Upper limit: 2,500mg a day (2,000mg over age 50).

Important interactions: Vitamin D is needed to absorb calcium. Some studies have linked calcium supplements — but not calcium from food — with more calcium deposits in the arteries, though the evidence is debated. Vitamin K2’s role in directing calcium to bone is plausible but not proven in trials. Getting most of your calcium from food is the safest approach.

2. Magnesium

Magnesium is a cofactor in more than 300 enzyme reactions, including those that make and use ATP, the body’s energy currency. It’s essential for muscle and nerve function, heart rhythm, blood pressure, blood sugar control and insulin sensitivity, DNA and protein synthesis, and bone formation. Many people don’t reach the recommended intake — about half of US adults fall short — although clinically low blood magnesium is uncommon in healthy people.

Key functions: 300+ enzyme reactions, ATP energy production, muscle contraction and relaxation, nerve function, heart rhythm, blood pressure regulation, blood sugar and insulin regulation, bone formation, DNA and protein synthesis.

Deficiency symptoms: Low intake over time is linked with higher blood pressure and a higher risk of type 2 diabetes. True magnesium deficiency — usually caused by gut losses, alcohol misuse, poorly controlled diabetes, or medicines such as diuretics and long-term proton pump inhibitors — causes loss of appetite, nausea, fatigue, and weakness, and in more severe cases, tingling, muscle cramps and spasms, abnormal heart rhythms, and seizures.

Best food sources: Pumpkin seeds (one of the richest sources), chia and flaxseeds, Brazil nuts, almonds, cashews, dark chocolate, spinach, black beans, edamame, tofu, quinoa, whole grains.

Recommended daily intake: 310–420mg for adults (310–320mg for women, 400–420mg for men). Upper limit for magnesium from supplements and medicines: 350mg a day — magnesium from food doesn’t count towards it.

Supplementation: Magnesium citrate and glycinate are both well absorbed; citrate can loosen stools at higher doses. Magnesium oxide is less well absorbed. Supplements help most when dietary intake is low. They’re popular for sleep, but the evidence is limited, and a Cochrane review found they’re unlikely to prevent common muscle cramps.

3. Potassium

Potassium is the main positively charged ion inside cells, making it essential for the electrical gradients that drive nerve impulses and muscle contractions. It works in close partnership with sodium — together they regulate fluid balance inside and outside cells through the sodium-potassium pump, one of the most fundamental mechanisms in human physiology. Potassium is critical for heart rhythm, and a potassium-rich diet helps counteract the blood-pressure-raising effects of sodium. Most people don’t get enough, because potassium comes mainly from fruits, vegetables, and legumes — foods that are chronically under-eaten.

Key functions: Fluid balance and cell hydration, nerve impulse transmission, muscle contraction (including heart muscle), blood pressure regulation (counteracting sodium), kidney function.

Deficiency symptoms: A low-potassium diet raises blood pressure and the risk of kidney stones. Low blood potassium (hypokalemia) — usually caused by diuretics, vomiting, or diarrhea rather than diet — causes muscle weakness, cramps, fatigue, constipation, and abnormal heart rhythms, and severe cases can be life-threatening.

Best food sources: Potatoes with skin, sweet potatoes, beans and lentils, dried fruit such as raisins, spinach and beet greens, avocado, salmon, bananas, yogurt, pistachios, coconut water.

Recommended daily intake: 2,600mg for women and 3,400mg for men. Most people consume significantly less. No upper limit is set for potassium from food.

Note: People with kidney disease, and those taking medicines that raise potassium — such as ACE inhibitors, angiotensin receptor blockers, and potassium-sparing diuretics — should talk to a doctor before increasing potassium intake or using potassium-based salt substitutes.

4. Sodium

Sodium is the main positively charged ion outside cells and is essential for fluid balance, nerve impulses, and muscle contraction. It works with potassium in the sodium-potassium pump, and it’s the main regulator of blood volume — which is why excessive sodium intake is strongly linked with high blood pressure. Despite its bad reputation, sodium is essential, and low blood sodium (hyponatremia) is dangerous. The issue for most people is excess, not deficiency: most people eat far more sodium than they need, and about 70% of it comes from processed and restaurant foods rather than the salt shaker.

Key functions: Fluid balance and blood volume regulation, nerve impulse transmission, muscle contraction, nutrient absorption in the intestines, blood pressure regulation.

Deficiency symptoms: Hyponatremia — nausea, headache, confusion, fatigue, muscle weakness, and in severe cases, seizures and coma. In endurance events, the main cause is drinking too much fluid, often combined with heavy sweat losses. Some medicines and medical conditions can also cause it.

Main food sources: Processed and restaurant foods provide most dietary sodium — bread, cheese, cured meats, sauces, olives, and pickles are major contributors, along with table salt. Whole foods contain small natural amounts.

Recommended daily intake: The adequate intake for adults is 1,500mg. Cutting intake below 2,300mg a day lowers the risk of chronic disease, and the World Health Organization recommends less than 2,000mg. Most adults eat far more.

For athletes: Heavy sweaters in long events, especially in the heat, may need to replace sodium with salty foods, sports drinks, or electrolyte products — but drinking to thirst rather than overdrinking is the best protection against hyponatremia.

5. Phosphorus

Phosphorus is the second most abundant mineral in the body after calcium — about 85% is in bones and teeth, where it works alongside calcium to provide structural strength. The rest is involved in energy production (phosphate is part of ATP, the body’s energy currency), cell membranes (phospholipids), DNA and RNA, and acid-base balance. It’s involved in virtually every metabolic process in the body, despite receiving less attention than calcium and magnesium.

Key functions: Bone and tooth structure (with calcium), ATP energy production, cell membrane formation (phospholipids), DNA and RNA structure, acid-base balance, enzyme and protein activation.

Deficiency symptoms: True deficiency is rare, because phosphorus is found in almost all foods. Low phosphate levels usually have medical causes — such as refeeding after starvation, alcohol misuse, or long-term use of aluminium-containing antacids — and cause bone pain, muscle weakness, fatigue, and poor appetite.

Best food sources: Dairy products, meat, fish, poultry, eggs, nuts and seeds, legumes, whole grains. Phosphorus is one of the easiest minerals to get from diet.

Recommended daily intake: 700mg for adults (1,250mg for ages 9–18). Most adults already get around 1,200–1,600mg a day. Upper limit: 4,000mg a day (3,000mg over age 70).

Note: The calcium-to-phosphorus ratio matters most in infancy and is less important for healthy adults than once thought. The bigger concern is phosphate additives in processed foods, which are absorbed far more efficiently — up to about 90% — than the phosphorus in seeds, grains, and legumes, where often only around half is absorbed. This is a particular issue for people with kidney disease.

6. Chloride

Chloride is the main negatively charged ion in the fluid outside cells, working with sodium and potassium to maintain fluid balance and acid-base balance. It’s needed to make hydrochloric acid (HCl) in the stomach, and it helps transmit nerve signals. Most people get more than enough chloride from salt (sodium chloride), so deficiency is rare in healthy adults eating a normal diet.

Key functions: Fluid balance and pH regulation, hydrochloric acid production (stomach acid), nerve transmission, electrolyte balance with sodium and potassium.

Deficiency symptoms: Rare. Chloride depletion is mainly caused by prolonged vomiting or certain diuretics, and leads to metabolic alkalosis, dehydration, and muscle weakness. (Diarrhea, by contrast, usually causes high chloride levels.)

Best food sources: Table salt and salty foods provide almost all dietary chloride. Smaller amounts come from seaweed, tomatoes, lettuce, celery, and olives.

Recommended daily intake: 2,300mg for adults aged 19–50, 2,000mg for ages 51–70, and 1,800mg over 70 — supplied naturally alongside sodium in salt. Upper limit: 3,600mg a day.

Trace Minerals (Micro-Minerals)

7. Zinc

Zinc is one of the most important trace minerals for anyone who trains. It’s involved in hundreds of enzyme reactions — about 10% of human proteins bind zinc — and plays critical roles in immune function, wound healing, protein and DNA synthesis, cell division, growth, and taste and smell. It also supports normal testosterone production: deficiency lowers testosterone, although zinc supplements don’t raise it in people who already get enough. Athletes on restrictive or vegetarian diets are among those most likely to fall short.

Key functions: Immune function (including T-cell development), wound healing, protein and DNA synthesis, normal testosterone production, growth, taste and smell, antioxidant enzyme function, cell division.

Deficiency symptoms: Frequent infections, slow wound healing, hair loss, loss of appetite and taste, a scaly skin rash, low testosterone, and impaired growth and development in children.

Best food sources: Oysters (the highest concentration by far), beef, lamb, pork, crab, pumpkin seeds, hemp seeds, cashews, chickpeas, lentils, oats, cheese. Phytates in plant foods reduce zinc absorption.

Recommended daily intake: 8mg for women and 11mg for men. Vegetarians may need up to 50% more, because phytates in plant foods reduce absorption. Upper limit: 40mg a day.

Supplementation: Zinc citrate, gluconate, picolinate, and bisglycinate are well absorbed; zinc oxide less so. Long-term doses of around 50mg a day or more can deplete copper. Avoid zinc nasal sprays and gels — they’ve been linked with permanent loss of smell.

8. Copper

Copper is part of several key enzymes: cytochrome c oxidase (the final step of aerobic energy production), copper-zinc superoxide dismutase (an antioxidant enzyme), and lysyl oxidase (which cross-links collagen and elastin, giving connective tissue its strength). Copper enzymes are also needed to move iron out of storage and from the gut into the blood — which is why copper deficiency causes anemia that iron supplements alone can’t fix.

Key functions: Energy production (electron transport chain), iron transport and red blood cell formation, collagen and elastin cross-linking (connective tissue), antioxidant defense (SOD enzyme), nervous system health, melanin production.

Deficiency symptoms: Anemia that doesn’t respond to iron, a low white blood cell count, nerve damage that can mimic vitamin B12 deficiency, weak bones, pale skin, and fatigue. Deficiency is uncommon but often missed — the most common causes are long-term high-dose zinc and weight-loss surgery.

Best food sources: Organ meats (a single serving of beef liver exceeds the upper limit, so eat it occasionally), oysters and other shellfish, cashews, sunflower seeds, dark chocolate, sesame seeds, mushrooms, lentils, chickpeas.

Recommended daily intake: 900mcg for adults. Upper limit: 10mg a day.

Note: Long-term high-dose zinc causes the gut lining to trap copper, through a protein called metallothionein, so less copper is absorbed. If you take zinc supplements for months, choose a product that includes 1–2mg of copper.

9. Fluoride

Fluoride’s main role is protecting teeth from decay. Its biggest effect is topical: fluoride in saliva and plaque — from toothpaste, fluoridated water, and dental treatments — slows the loss of minerals from enamel during acid attacks, speeds up repair, and reduces acid production by mouth bacteria. Some fluoride is also built into developing enamel and bone. Many countries add fluoride to public water supplies, though most of Europe doesn’t, and fluoridation policies are actively debated (see our Fluoride page).

Key functions: Preventing tooth decay, repairing early enamel damage, reducing acid production by mouth bacteria.

Deficiency symptoms: More tooth decay. Fluoride isn’t considered an essential nutrient by European authorities, and low intake doesn’t cause a disease of its own — but low fluoride exposure raises the risk of cavities. Fluoride increases bone density, but it hasn’t been shown to prevent fractures.

Best food sources: Fluoridated water, tea (black tea provides about 0.9mg per cup), some seafood such as canned shrimp and crab, raisins, and foods and drinks made with fluoridated water — plus fluoride toothpaste for topical protection.

Recommended daily intake: 3mg for women and 4mg for men. Upper limit: 10mg a day for ages 9 and over, and much lower for young children.

Note: Swallowing too much fluoride while teeth are forming (up to about age 8) can cause dental fluorosis — usually faint white marks, which are common, and only rarely brown staining at much higher exposures. Skeletal fluorosis occurs only after years of very high exposure, usually from naturally high-fluoride groundwater. Research linking high fluoride exposure with lower IQ in children is covered on our Fluoride page.

10. Iodine

Iodine is essential for making the thyroid hormones thyroxine (T4) and triiodothyronine (T3), which regulate metabolism, growth, and development throughout the body. Almost every cell depends on thyroid hormones, making iodine one of the most broadly important trace minerals. Iodine deficiency is the world’s leading preventable cause of intellectual disability, because the developing baby’s brain depends on the mother’s thyroid hormones.

Key functions: Thyroid hormone synthesis (T3 and T4), metabolic rate regulation, growth and development, brain development (critical during pregnancy and infancy).

Deficiency symptoms: Hypothyroidism — fatigue, weight gain, cold intolerance, constipation, dry skin, hair loss, brain fog. Goitre (an enlarged thyroid gland). Severe deficiency during pregnancy causes cretinism — irreversible intellectual disability and developmental problems in the child.

Best food sources: Cod and other white fish, oysters, dairy products, eggs, iodized salt, and seaweed — though seaweed varies enormously, and a single gram of some kelp can exceed the upper limit. Most plant foods and plant milks are low in iodine, and specialty salts such as sea salt and Himalayan salt are usually not iodized.

Recommended daily intake: 150mcg for adults, 220mcg during pregnancy, and 290mcg while breastfeeding. Upper limit: 1,100mcg a day.

Particularly important for: Pregnant and breastfeeding women (the American Thyroid Association recommends a daily supplement containing 150mcg), vegans and people who eat little dairy or seafood, people who don’t use iodized salt, and those living in regions with iodine-poor soil.

11. Iron

Iron is perhaps the best-known trace mineral and one of the most important for athletic performance. It’s the central component of hemoglobin — the protein in red blood cells that carries oxygen from your lungs to your muscles and tissues — and of myoglobin, which holds oxygen inside muscle cells. Iron is also essential for energy production, immune function, and brain development. Iron deficiency is the most common nutritional deficiency worldwide and significantly impairs exercise performance, recovery, and concentration.

Key functions: Hemoglobin synthesis (oxygen transport in blood), myoglobin synthesis (oxygen storage in muscles), ATP energy production, immune cell function, brain development, thyroid hormone production.

Deficiency symptoms: Fatigue and weakness, pale skin, shortness of breath during exercise, cold hands and feet, headaches, dizziness, poor concentration, reduced exercise performance, restless legs, and cravings for ice. Iron deficiency anaemia is the most advanced stage — symptoms often begin earlier, when only iron stores (ferritin) are low.

Best food sources:

• Hem iron (animal sources — best absorbed): Beef liver, oysters, mussels, beef and lamb, dark poultry meat, sardines
• Non-hem iron (plant sources — less well absorbed): Lentils, chickpeas, tofu, pumpkin seeds, cashews, fortified cereals and enriched bread, dark chocolate, spinach (though very little of spinach’s iron is absorbed)

Recommended daily intake: 8mg for men and post-menopausal women, 18mg for premenopausal women (higher because of menstrual losses), and 27mg during pregnancy. Vegetarians need about 1.8 times as much. Upper limit: 45mg a day.

Absorption tips: Eating vitamin C-rich foods alongside non-hem iron sources significantly improves absorption. Avoid tea, coffee, and calcium supplements with iron-rich meals, as they reduce iron absorption.

Particularly important for: Premenopausal women, pregnant women, endurance athletes (who have higher iron losses), and vegans and vegetarians (non-hem iron is less well absorbed).

Safety note: Men and post-menopausal women shouldn’t take iron supplements unless a blood test shows they need them — the body can’t get rid of excess iron, and hemochromatosis, a genetic iron-overload condition, is common in people of Northern European descent. In these groups, iron deficiency without an obvious cause should always be checked by a doctor, as it can be a sign of hidden bleeding in the gut.

12. Manganese

Manganese is a cofactor for several enzymes involved in energy production, bone and cartilage formation, and antioxidant defense. It’s a key part of manganese superoxide dismutase (MnSOD) — the main antioxidant enzyme inside the mitochondria, protecting them from the oxidative damage produced during energy production. It also helps recycle proline for collagen, supporting wound healing, and is involved in the metabolism of glucose, amino acids, and cholesterol.

Key functions: Antioxidant defense (MnSOD enzyme), bone and cartilage development, collagen formation and wound healing, energy metabolism (carbohydrate, amino acid, and cholesterol metabolism), brain and nervous system function.

Deficiency symptoms: Deficiency is very rare — so rare that its effects in people aren’t well understood. Small experiments with very low-manganese diets have reported a skin rash and changes in cholesterol and mood; animal studies show impaired bone growth and glucose metabolism.

Best food sources: Macadamia nuts, pine nuts, mussels, hazelnuts, pecans, chia seeds, oats, whole wheat bread, brown rice, legumes, leafy green vegetables, tea.

Recommended daily intake: 1.8mg for women and 2.3mg for men. Upper limit: 11mg a day.

Note: With manganese, the bigger concern is excess. Industrial exposure, as in welding and mining, can cause a Parkinson’s-like condition, and some glucosamine and chondroitin joint supplements contain enough manganese to push intake towards the upper limit. High manganese levels in well water have been linked with lower IQ in children, and people with liver disease can build up manganese even at normal intakes.

13. Molybdenum

Molybdenum is needed by four enzymes. The most important, sulfite oxidase, converts sulfite — produced when the body breaks down sulfur-containing amino acids — into harmless sulfate. Without this enzyme, sulfite builds up to toxic levels. Other molybdenum enzymes break down purines into uric acid and process aldehydes and many drugs and toxins in the liver. Dietary deficiency has never been reported in healthy people.

Key functions: Sulfite detoxification (sulfite oxidase), purine breakdown (uric acid production), aldehyde and drug metabolism in the liver.

Deficiency symptoms: Never reported in healthy people eating normal diets. In a single case of a patient on long-term intravenous feeding without molybdenum, deficiency caused a rapid heart rate, night blindness, and coma, and a rare inherited disorder that stops the body from using molybdenum causes severe brain damage in newborns. Sensitivity to sulfites in wine and dried fruit isn’t caused by low molybdenum.

Best food sources: Legumes (black-eyed peas and lima beans are especially rich), beef liver, whole grains, nuts, dairy products, leafy vegetables. Content varies significantly with soil molybdenum levels.

Recommended daily intake: 45mcg for adults — average intakes are well above this. Upper limit: 2,000mcg a day.

14. Selenium

Selenium is built directly into about 25 proteins called selenoproteins. They include the glutathione peroxidases — antioxidant enzymes that work with glutathione, a major cellular antioxidant, to neutralize hydrogen peroxide and protect cells from oxidative damage — and the deiodinases, which convert the thyroid hormone T4 into the more active T3. Selenium also supports immune function, DNA synthesis, and male fertility. Observational studies once suggested that higher selenium status protects against cancer, but large trials found that supplements don’t prevent cancer in people who already get enough — and 200mcg a day was linked with a higher risk of type 2 diabetes.

Key functions: Glutathione peroxidase antioxidant function, thyroid hormone activation (T4 to T3 conversion), immune function, DNA synthesis and protection, male fertility (sperm structure and movement).

Deficiency symptoms: Weakened immune function, muscle weakness, and thyroid problems in severe deficiency. Keshan disease (a heart muscle disease) and Kashin-Beck disease (a joint and bone disorder) occur in severely selenium-deficient regions.

Best food sources: Brazil nuts (extremely variable — anywhere from about 15mcg to nearly 100mcg per nut), oysters, mussels, tuna, halibut, sardines, shrimp, pork, chicken, eggs, and grains grown in selenium-rich soil.

Recommended daily intake: 55mcg for adults. Upper limit: 400mcg a day.

Supplementation note: Selenium’s safe range is narrower than for most minerals. Because Brazil nuts vary so much, don’t rely on them alone or eat them in large amounts. If your intake is likely to be low — for example, in low-selenium regions such as much of Europe — a modest supplement of 50–100mcg is plenty; avoid long-term doses of 200mcg or more if your intake is already adequate. Above the upper limit, selenosis — hair loss, brittle nails, and garlic breath — can develop.

15. Chromium

Chromium is the most debated mineral on this list. It may enhance the action of insulin — possibly through a chromium-binding molecule called chromodulin — but the mechanism hasn’t been established. The US set intake recommendations in 2001, but newer research has questioned whether chromium is essential at all, and in 2014, the European Food Safety Authority found no convincing evidence that it is. Chromium picolinate is a popular supplement for blood sugar and body composition, but trial effects are small: slight reductions in blood sugar in people with diabetes, of unclear clinical significance, and less than 1kg of extra weight loss.

Key functions: Possibly enhancing insulin action and glucose metabolism.

Deficiency symptoms: Never reported in healthy people, and there’s no reliable test for chromium status. Older reports of deficiency in patients on intravenous feeding are no longer considered proof that deficiency exists.

Best food sources: Small amounts are found in many foods, including grape juice, ham, whole grains, brewer’s yeast, beef, turkey, green beans, apples, and broccoli. Amounts vary widely, and stainless steel cookware adds a little to food.

Recommended daily intake: 20–35mcg for adults (the US adequate intake, depending on age and sex). No upper limit has been set, but European regulators advise keeping supplemental chromium at or below 250mcg a day. Chromium may add to the effects of diabetes medicines, so talk to your doctor first if you take them.

Minerals Most Important for Athletes and Active People

If you train regularly, these minerals deserve particular attention — through food first, with supplements guided by real need:

Iron — critical for oxygen transport and endurance performance. Female athletes and endurance athletes are at highest risk of deficiency. Check ferritin rather than guessing, and if you need iron, take it in the morning — before training or within about 30 minutes after.

Sodium — the main electrolyte lost in sweat. During long events in the heat, replacing sodium matters, but drinking to thirst rather than overdrinking is the best protection against dangerous hyponatremia. Potassium losses in sweat are much smaller, and a diet rich in fruit and vegetables covers them.

Calcium — bone density is a long-term investment. Weight-bearing exercise and adequate calcium and vitamin D support bone health, and athletes who don’t eat enough to match their training — especially women with missed periods — are at higher risk of stress fractures.

Magnesium — lost in sweat, and some athletes, especially those restricting food, don’t reach the recommended intake. Food comes first; supplements help when intake is low, but they don’t prevent common muscle cramps.

Zinc — supports immune function, recovery, and protein synthesis. Deficiency lowers testosterone, but zinc supplements don’t raise it in athletes who already get enough. Vegetarian athletes and those restricting energy intake are most at risk.

Iodine — athletes who avoid dairy, seafood, and iodized salt at the same time can run low, affecting thyroid function, metabolism, and energy.

Selenium — supports the body’s own antioxidant enzymes, which adapt to training. Adequate intake is enough; high-dose supplements offer no performance benefit and carry risks.

Getting Enough Minerals from Your Diet

A varied, whole-food diet is the most reliable foundation for getting enough minerals:

Eat a wide variety of vegetables, fruits, and legumes — they’re the main sources of potassium and magnesium. Low-oxalate greens such as kale and bok choy provide well-absorbed calcium, while the calcium and iron in spinach are poorly absorbed.

Choose whole grains over refined grains — refining strips out much of the magnesium, manganese, and other minerals. Whole wheat bread, for example, contains more than three times as much manganese as white bread.

Include quality protein sources — meat, fish, and seafood provide well-absorbed zinc, iron, and selenium, which are harder (though not impossible) to get in sufficient amounts from plant foods alone.

Don’t fear dairy — it remains one of the most efficient sources of calcium, phosphorus, and, in many countries, iodine.

Eat nuts and seeds regularly — pumpkin seeds for zinc and magnesium, cashews and sesame seeds for copper, and an occasional Brazil nut for selenium (in moderation, as their content varies widely).

Use iodized salt if you use salt — sea salt, Himalayan salt, and other specialty salts usually contain no iodine.

Consider your water — hard tap water and some mineral waters can contribute meaningfully to calcium and magnesium intake.

Supplement selectively — the minerals most often worth supplementing are iron (when a blood test shows a deficiency) and iodine (during pregnancy), with calcium, magnesium, or zinc sometimes useful when your diet falls short. More isn’t better: for several minerals, the upper limit isn’t far above the recommended intake.

Related Nutrition Pages

Omega-3 — essential fatty acids and their benefits

Basic Nutrition — macronutrients, calories, and nutrition fundamentals

Vitamins — the 13 essential vitamins

Amino Acids — the building blocks of protein