Minerals are inorganic elements your body needs for everything from building bone to transmitting nerve signals to balancing fluids. They're grouped into two categories based on how much you need each day: macrominerals and trace minerals.
Macrominerals
These are needed in larger daily quantities, generally hundreds of milligrams per day.
Calcium
Essential for bone mineralization, nerve signaling, and muscle contraction. Found in dairy, legumes, and vegetables. Adults generally need 800–1,000 mg/day.
Phosphorus
A structural component of bone, teeth, cell membranes, and DNA, and central to energy metabolism. Found in dairy, meat, and poultry. Adults need about 700 mg/day.
Potassium
The main mineral inside your cells, important for blood pressure regulation, muscle contraction, and acid-base balance. Potatoes have the highest potassium content of any common food; other sources include fruits, vegetables, and dairy. Adequate intake is around 4,700 mg/day.
Sodium
Essential for fluid balance, nerve transmission, and muscle contraction. Most dietary sodium comes from processed foods rather than the salt shaker. Adequate intake for adults is roughly 1,500 mg/day.
Magnesium
Involved in hundreds of biochemical reactions, including energy transfer, bone development, and neuromuscular function. Found in nuts, legumes, whole grains, and leafy greens. RDA for adults is about 400 mg/day — and research consistently finds roughly half of U.S. adults fall short, making it one of the more common shortfall minerals in the modern diet.
Trace Minerals
Needed in much smaller amounts — milligrams or even micrograms per day — but no less essential.
| Mineral | Main Role | Good Sources | Adult Target |
|---|---|---|---|
| Iron | Oxygen transport in blood | Meat, fortified grains, leafy greens | 8–18 mg/day |
| Zinc | Cofactor for 300+ enzymes, immune function | Fish, oysters, red meat, legumes | ~10 mg/day |
| Copper | Redox enzyme cofactor, metabolism | Whole grains, liver, oysters, nuts | ~1 mg/day |
| Manganese | Immune function, glucose regulation | Whole grains, rice, nuts, legumes | ~2 mg/day |
| Selenium | Antioxidant systems | Brazil nuts, beef, fish, eggs | ~55 mcg/day |
| Iodine | Thyroid hormone synthesis | Iodized salt, seafood | ~150 mcg/day |
| Molybdenum | Enzyme cofactor (drug & amino acid metabolism) | Beans, grains, leafy vegetables | ~45 mcg/day |
Where Minerals Actually Come From
Mineral content in plant foods depends heavily on the soil they're grown in — a vegetable grown in mineral-rich soil generally contains more minerals than the same vegetable grown in depleted soil. This is part of why food quality and source can matter for micronutrient intake, separate from just choosing the right food categories.
A Word on Magnesium and Selenium
Magnesium deserves special attention because shortfall intake is so common, and its deficiency symptoms (muscle cramps, fatigue, mood changes) are nonspecific and easy to mistake for something else.
Selenium is unusual among micronutrients in having a narrow safety range — both too little and too much are associated with health problems, and the right amount depends partly on which chemical form of selenium you're getting.