Knowledge Base / Minerals
Minerals A to Z
What each one does, how much you need, and where to find it.
A practical guide to 12 key minerals. Compare daily recommendations, see how much common foods actually provide, and learn what to know before taking a supplement. Most people get enough from a varied diet; the common gaps are potassium, calcium and magnesium, and iron for some women.
Quick reference
Compare daily needs, upper limits and common food sources at a glance.
| Mineral | Main role | Daily amount | Upper limit | Food sources |
|---|---|---|---|---|
| Calcium | Bones, teeth, muscles and nerves | 1,000–1,200 mg | 2,500 mg (2,000 after 50) | Yogurt, milk, cheese, sardines with bones, calcium-set tofu, kale |
| Chromium | Insulin action and blood sugar | 25–35 mcg (AI) | Not established | Broccoli, grape juice, whole grains, meat, potatoes |
| Copper | Uses iron, builds connective tissue | 900 mcg | 10,000 mcg (10 mg) | Oysters, beef liver, cashews, lentils, dark chocolate, mushrooms |
| Iodine | Thyroid hormones; baby's brain | 150 mcg (220 in pregnancy) | 1,100 mcg | Iodized salt, seaweed, cod, milk, yogurt, eggs |
| Iron | Carries oxygen in red blood cells | 8–18 mg (27 in pregnancy) | 45 mg | Oysters, beef, lentils, spinach, beans, fortified cereals |
| Magnesium | Muscles, nerves, blood sugar, energy | 310–420 mg | 350 mg (supplements only) | Pumpkin seeds, almonds, spinach, cashews, black beans |
| Manganese | Bone formation and metabolism | 1.8–2.3 mg (AI) | 11 mg | Oats, brown rice, pumpkin seeds, spinach, pineapple, tea |
| Phosphorus | Bones, teeth and cell energy (ATP) | 700 mg | 4,000 mg (3,000 after 70) | Yogurt, milk, salmon, chicken, lentils, nuts |
| Potassium | Fluid balance, heart rhythm, blood pressure | 2,600–3,400 mg (AI) | Not established | Avocado, bananas, lentils, potatoes, beans, dried apricots |
| Selenium | Antioxidant enzymes, thyroid | 55 mcg | 400 mcg | Brazil nuts, tuna, sardines, eggs, whole grains |
| Sodium | Fluid balance, nerves and muscles | 1,500 mg (AI) | Cut back if above 2,300 mg (CDRR) | Mostly packaged and restaurant food: bread, deli meats, pizza, soups, snacks |
| Zinc | Immunity, wound healing, taste | 8–11 mg | 40 mg | Oysters, beef, crab, pumpkin seeds, cashews, chickpeas |
General guidance for healthy adults; needs vary by age, sex, pregnancy and breastfeeding. Ranges run from women to men (calcium rises to 1,200 mg for women over 50 and everyone over 70; iron is 18 mg for women 19-50 and 8 mg for men and for women after menopause). AI = adequate intake, CDRR = chronic disease risk reduction intake.
Upper limits count food, water and supplements, except magnesium, where the 350 mg limit applies only to supplements and medicines. No limit is set for potassium or chromium from food. Pregnant? See our prenatal vitamins guide.
Explore the minerals
Key numbers, real food amounts, who may run low and one safety point for each mineral.
Calcium
Ca · Macromineral
Builds bones and teeth and is needed for muscle contraction, nerve signals and blood clotting.
Daily amount: 1,000–1,200 mg|Upper limit: 2,500 mg (2,000 after 50)
- 8 oz plain low-fat yogurt415 mg
- 1 cup 2% milk293 mg
- 3 oz canned sardines with bones325 mg
Who may run low: Postmenopausal women and people who avoid dairy (vegans, lactose intolerance or milk allergy).
Safety: Too much, mostly from supplements, raises the risk of kidney stones and constipation. Take no more than 500 mg at a time for best absorption.
Chromium
Cr · Trace mineral
May help insulin work, which affects how your body handles blood sugar. Evidence for supplements is mixed.
Daily amount: 25–35 mcg (AI)|Upper limit: Not established
Food sources: Broccoli, grape juice, whole grains, meat, potatoes
Safety: Rare reports link high-dose chromium picolinate to kidney and liver problems. If you use insulin or diabetes medicines, check with your doctor: blood sugar may drop.
Copper
Cu · Trace mineral
Helps your body use iron, make red blood cells and connective tissue, and keep nerves and immune cells healthy.
Daily amount: 900 mcg|Upper limit: 10,000 mcg (10 mg)
- 3 oz cooked farmed oysters1,216 mcg
- 1 oz dry-roasted cashews629 mcg
- ½ cup cooked lentils248 mcg
Who may run low: People with celiac disease or after weight-loss surgery, and people taking high doses of zinc.
Safety: Long-term high-dose zinc supplements can cause copper deficiency. Copper excess from food is rare.
Iodine
I · Trace mineral
Needed to make thyroid hormones, which control metabolism and, in pregnancy, the baby's brain development.
Daily amount: 150 mcg (220 in pregnancy)|Upper limit: 1,100 mcg
Food sources: Iodized salt, seaweed, cod, milk, yogurt, eggs
Who may run low: People who do not use iodized salt, pregnant and breastfeeding women, and vegans who eat no dairy or seafood.
Safety: Both too little and too much iodine can cause thyroid problems. Kelp and seaweed supplements can contain far more than you need.
Iron
Fe · Trace mineral
Part of hemoglobin, which carries oxygen in your blood. Low iron leads to fatigue and anemia.
Daily amount: 8–18 mg (27 in pregnancy)|Upper limit: 45 mg
- 3 oz cooked farmed oysters6.6 mg
- ½ cup cooked lentils3.3 mg
- ½ cup cooked spinach3.2 mg
Who may run low: Pregnant women, infants and toddlers, women with heavy periods, frequent blood donors, and people with GI disorders or heart failure.
Safety: Take iron only if a blood test shows you need it. Iron supplements are a leading cause of fatal poisoning in children under 6, so store them out of reach.
Magnesium
Mg · Macromineral
Involved in more than 300 enzyme reactions, including muscle and nerve function, blood sugar control and energy production.
Daily amount: 310–420 mg|Upper limit: 350 mg (supplements only)
- 1 oz roasted pumpkin seeds156 mg
- 1 oz almonds77 mg
- ½ cup cooked spinach78 mg
Who may run low: Older adults, people with type 2 diabetes, Crohn's or celiac disease, and people with alcohol dependence.
Safety: Supplement doses above 350 mg often cause diarrhea. With kidney disease, take magnesium only on a doctor's advice.
Manganese
Mn · Trace mineral
Helps form bone and is part of enzymes that process carbohydrates, cholesterol and amino acids.
Daily amount: 1.8–2.3 mg (AI)|Upper limit: 11 mg
- ½ cup dry oats1.5 mg
- 1 oz roasted pumpkin seeds1.3 mg
- ½ cup cooked spinach0.8 mg
Safety: Deficiency is very rare. Toxicity comes mainly from inhaled dust or contaminated well water, not from food.
Phosphorus
P · Macromineral
Works with calcium to build bones and teeth and is part of ATP, the energy molecule in every cell.
Daily amount: 700 mg|Upper limit: 4,000 mg (3,000 after 70)
- 8 oz plain low-fat yogurt327 mg
- 3 oz cooked salmon259 mg
- ½ cup cooked lentils178 mg
Safety: Deficiency is rare. People with kidney disease often need to limit phosphorus, including phosphate additives in processed foods.
Potassium
K · Macromineral
Keeps fluid balance and nerve and heart signals working. Potassium-rich diets are linked to lower blood pressure.
Daily amount: 2,600–3,400 mg (AI)|Upper limit: Not established
- ½ avocado487 mg
- 1 medium banana422 mg
- ½ cup cooked lentils365 mg
Who may run low: People with inflammatory bowel disease and people who use certain diuretics or laxatives.
Safety: Potassium supplements can be dangerous with kidney disease or with ACE inhibitors, ARBs or potassium-sparing diuretics. Most US supplements contain 99 mg or less.
Selenium
Se · Trace mineral
Part of antioxidant enzymes and needed for thyroid hormone metabolism and DNA production.
Daily amount: 55 mcg|Upper limit: 400 mcg
- 1 oz Brazil nuts (6–8 nuts)544 mcg
- 3 oz canned light tuna60 mcg
- 3 oz canned sardines45 mcg
- 1 large egg15 mcg
Who may run low: People on kidney dialysis, people living with HIV, and people in regions with selenium-poor soil.
Safety: Just 1-2 Brazil nuts can exceed the daily need. Long-term intake above 400 mcg can cause hair and nail loss and a garlic odor on the breath.
Sodium
Na · Macromineral
Controls fluid balance and helps nerves and muscles work. Most Americans get far more than they need.
Daily amount: 1,500 mg (AI)|Upper limit: Cut back if above 2,300 mg (CDRR)
Food sources: Mostly packaged and restaurant food: bread, deli meats, pizza, soups, snacks
Safety: Above 2,300 mg a day (about 1 teaspoon of salt), cutting back lowers blood pressure and heart disease risk.
Zinc
Zn · Trace mineral
Supports immune function, wound healing, DNA production and your sense of taste and smell.
Daily amount: 8–11 mg|Upper limit: 40 mg
- 3 oz cooked farmed oysters38.4 mg
- 1 oz roasted pumpkin seeds2.2 mg
- 1 oz dry-roasted cashews1.6 mg
Who may run low: Vegetarians, people with digestive disorders or GI surgery, pregnant and breastfeeding women, and people with alcohol use disorder.
Safety: More than 40 mg a day for long periods can cause copper deficiency. Zinc nasal sprays have caused permanent loss of smell.
No mineral matches your search. Try a food (oysters), a function (bones) or a name (zinc).
Formulas and testing
Multi-mineral products and how mineral levels are actually checked.
Multi-Mineral Formulas
Several minerals in one product. Check that zinc and copper are balanced and that iron is included only if you need it.
Testing Your Mineral Levels
Blood tests are the standard for iron (ferritin) and most minerals. Hair tissue mineral analysis shows longer-term patterns but has real limitations; read both sides before ordering one.
Minerals That Compete
High-dose zinc lowers copper absorption, and calcium can reduce iron absorption. If you take calcium and iron, take them at least 2 hours apart.
Common questions
What are the essential minerals?
Your body needs about 15 minerals. Macrominerals such as calcium, phosphorus, magnesium, sodium and potassium are needed in amounts above 100 mg a day. Trace minerals such as iron, zinc, copper, iodine, selenium, manganese and chromium are needed in much smaller amounts, from micrograms to a few milligrams.
Which minerals are people most often low in?
US surveys show many adults get less potassium, calcium and magnesium than recommended. Calcium and potassium are listed as nutrients of public health concern in the Dietary Guidelines for Americans 2020-2025. Worldwide, iron deficiency is the most common nutrient deficiency.
Do minerals compete with each other for absorption?
Yes. Zinc above 40 mg a day can reduce copper absorption, and calcium can lower iron absorption when taken together. If you take calcium and iron, take them at least 2 hours apart.
What is the best form of magnesium?
Citrate, glycinate and chloride are absorbed better than oxide. Glycinate is gentle on the stomach, citrate has a mild laxative effect, and oxide packs the most magnesium per pill but is absorbed poorly. Supplement doses above 350 mg a day often cause diarrhea.
Should I take iron for tiredness?
Only if a blood test (ferritin and hemoglobin) shows low iron. Unneeded iron builds up in the liver and heart, and hereditary hemochromatosis makes some people store too much even at normal intakes. The adult upper limit is 45 mg a day.
How much salt is too much?
Cutting back is advised above 2,300 mg of sodium a day, about 1 teaspoon of salt. The average American eats about 3,400 mg, and most of it comes from packaged and restaurant food rather than the salt shaker.
Is pink Himalayan salt healthier than table salt?
It has about the same amount of sodium and only traces of other minerals, too little to matter for health. Unlike iodized table salt, it usually has no added iodine, which matters if salt is your main iodine source.
Do Brazil nuts really have that much selenium?
Yes. One ounce (6-8 nuts) has about 544 mcg, above the 400 mcg upper limit. One or two nuts a day is plenty, and the amount varies widely with the soil where the trees grew.
How do I know if I am low in a mineral?
A blood test is the standard check for iron (ferritin) and is also used for zinc, magnesium and others, though blood levels do not always reflect body stores. Symptoms like cramps or fatigue have many causes, so test before taking high doses.
Can you get too much of a mineral from food?
Rarely. Problems almost always come from supplements. The main food exceptions are Brazil nuts (selenium), seaweed and kelp (iodine) and very salty processed food (sodium).