Minerals are inorganic elements that your body requires for numerous physiological functions—bone formation, nerve transmission, muscle contraction, blood oxygenation, fluid balance, and countless enzymatic reactions. Like vitamins, minerals are essential nutrients that must be obtained from the diet because the body cannot synthesize them. While they represent only a small fraction of body weight, minerals are involved in virtually every biological process.
Minerals are divided into two categories based on how much your body needs. Macrominerals—calcium, phosphorus, magnesium, sodium, potassium, chloride, and sulfur—are needed in relatively larger amounts, typically hundreds of milligrams or more daily. Trace minerals—iron, zinc, copper, manganese, selenium, iodine, chromium, molybdenum, and others—are needed in much smaller amounts, often micrograms, but are no less important.
Calcium
Calcium is the most abundant mineral in the body, with approximately 99% stored in bones and teeth where it provides structural strength. The remaining 1% circulates in blood and soft tissues, where it performs critical functions including muscle contraction, nerve transmission, blood clotting, and cell signaling. Blood calcium is tightly regulated—the body will pull calcium from bones to maintain stable blood levels if dietary intake is insufficient.
Calcium requirements are highest during periods of growth—childhood, adolescence, pregnancy, and lactation—but remain important throughout life to maintain bone density and prevent osteoporosis. Good food sources include dairy products, calcium-fortified plant milks and juices, canned fish with bones, tofu made with calcium sulfate, and leafy green vegetables like kale and bok choy. The Recommended Dietary Allowance for adults is 1000 to 1200 milligrams daily.
Magnesium
Magnesium is involved in over 300 enzymatic reactions in the body, including energy production, protein synthesis, muscle and nerve function, and blood glucose control. It also plays a structural role in bone and cell membranes. Despite its importance, magnesium deficiency is common, with estimates suggesting 50% or more of the US population falls short of the recommended intake.
Magnesium is found in nuts, seeds, whole grains, legumes, leafy green vegetables, and dark chocolate. Processing and refining grains removes much of their magnesium content, making processed food-heavy diets a risk factor for deficiency. Symptoms of magnesium deficiency include muscle cramps, fatigue, irritability, and in severe cases, cardiac arrhythmias. Many people with muscle cramps, restless legs, or poor sleep quality may benefit from magnesium supplementation.
Iron
Iron is essential for producing hemoglobin, the protein in red blood cells that carries oxygen from the lungs to tissues throughout the body. Iron also plays roles in energy metabolism, immune function, and cognitive development. Iron deficiency is the most common nutritional deficiency worldwide, affecting particularly women of childbearing age, children, and people with restricted diets.
There are two types of dietary iron: heme iron from animal sources (meat, poultry, fish) and non-heme iron from plant sources (legumes, fortified cereals, spinach). Heme iron is absorbed more efficiently than non-heme iron. Vitamin C enhances non-heme iron absorption, which is why consuming vitamin C-rich foods with iron-rich plant foods improves absorption. Tannins in tea and coffee can inhibit iron absorption, so it's best to avoid these beverages with iron-rich meals if you're trying to boost iron status.
Most people eating a varied, whole-food diet get adequate minerals. The most common mineral deficiencies—iron, magnesium, zinc—are typically easily corrected by improving diet quality rather than supplementation.
Zinc
Zinc is involved in immune function, protein synthesis, wound healing, DNA synthesis, and cell division. It also supports normal growth and development during pregnancy, childhood, and adolescence. Zinc deficiency impairs immune function, causes growth retardation, and can lead to hair loss, diarrhea, and delayed wound healing.
Good food sources include oysters (by far the richest source), red meat, poultry, crab, lobster, beans, nuts, and whole grains. Like iron, zinc from animal sources is absorbed more efficiently than zinc from plant sources. Phytates in whole grains and legumes can inhibit zinc absorption, so people following plant-heavy diets may need higher total zinc intake to maintain adequate status.
Calculate Your Mineral Intake
Use our nutrition calculator to assess whether your diet provides adequate minerals or if dietary improvements might help.
Assess Minerals →Potassium and Sodium
These two electrolytes work together to maintain fluid balance, nerve transmission, and muscle contraction, including the heart. The modern Western diet tends to be very high in sodium (from processed foods) and relatively low in potassium (from whole plant foods), contributing to elevated blood pressure in much of the population.
Most dietary potassium comes from fruits and vegetables—bananas, potatoes, spinach, beans, tomatoes, and avocados are all excellent sources. The DASH diet, designed to combat hypertension, emphasizes potassium-rich foods along with reduced sodium. Most adults should aim to increase potassium intake while reducing sodium, which typically means eating more whole plant foods and fewer processed foods.
Selenium
Selenium is a trace mineral that is essential for thyroid hormone metabolism, antioxidant defense, and immune function. The amount of selenium in foods depends on the selenium content of the soil where plants grew or animals grazed, making geographic variation in selenium intake significant. Brazil nuts are extraordinarily rich in selenium—just one or two nuts per day can meet your entire selenium requirement.
Other good sources include seafood, organ meats, and to a lesser extent, grains and meat. Selenium deficiency is relatively rare but can occur in regions with low soil selenium. Excessive selenium intake from supplements can cause selenosis, with symptoms including hair loss, gastrointestinal upset, and neurological abnormalities.
Other Important Trace Minerals
Iodine is essential for thyroid hormone production. The primary dietary source is iodized salt, with some seafood providing additional iodine. Chromium is involved in insulin action and glucose metabolism, found in broccoli, barley, and oats. Manganese is a cofactor for antioxidant enzymes and bone formation, abundant in whole grains, nuts, and leafy greens. Copper works with iron in hemoglobin formation, found in organ meats, shellfish, nuts, and seeds.
The take-home message for minerals is similar to vitamins: a varied, whole-food diet emphasizing vegetables, fruits, lean proteins, whole grains, nuts, and seeds provides adequate minerals for most people. Deficiencies are best addressed by improving dietary quality rather than reaching for supplements, with the possible exception of vitamin D, iron (when medically indicated), and B12 in older adults or those avoiding animal products.