Minerals are important for your body to stay healthy. Your body uses minerals for many different jobs, including keeping your bones, muscles, heart, and brain working properly. Minerals are also important for making enzymes and hormones.

There are two kinds of minerals: macrominerals and trace minerals. You need larger amounts of macrominerals. They include calcium, phosphorus, magnesium, sodium, potassium, chloride and sulfur. You only need small amounts of trace minerals. They include iron, manganese, copper, iodine, zinc, cobalt, fluoride and selenium.

Most people get the amount of minerals they need by eating a wide variety of foods. In some cases, your doctor may recommend a mineral supplement. People who have certain health problems or take some medicines may need to get less of one of the minerals. For example, people with chronic kidney disease need to limit foods that are high in potassium.

Minerals in food are inorganic compounds that work with other nutrients to ensure the body functions properly. Minerals cannot be made in the body; they come from the diet. The amount of minerals in the body is small—only 4 percent of the total body mass—and most of that consists of the minerals that the body requires in moderate quantities: potassium, sodium, calcium, phosphorus, magnesium, and chloride.

The most common minerals in the body are calcium and phosphorous, both of which are stored in the skeleton and necessary for the hardening of bones. Most minerals are ionized, and their ionic forms are used in physiological processes throughout the body. Sodium and chloride ions are electrolytes in the blood and extracellular tissues, and iron ions are critical to the formation of hemoglobin. There are additional trace minerals that are still important to the body’s functions, but their required quantities are much lower.

Like vitamins, minerals can be consumed in toxic quantities (although it is rare). A healthy diet includes most of the minerals your body requires, so supplements and processed foods can add potentially toxic levels of minerals. Tables below provide a summary of minerals and their function in the body.

Calcium is a mineral your body needs to build and maintain strong bones and to carry out many important functions. Calcium is the most abundant mineral in the body.

Almost all calcium in the body is stored in bones and teeth, giving them structure and hardness.

Your body needs calcium for muscles to move and for nerves to carry messages between your brain and every part of your body. Calcium also helps blood vessels move blood throughout your body and helps release hormones that affect many functions in your body. Vitamin D helps your body absorb calcium.

Copper is a mineral that you need to stay healthy. Your body uses copper to carry out many important functions, including making energy, connective tissues, and blood vessels. Copper also helps maintain the nervous and immune systems, and activates genes. Your body also needs copper for brain development.

Fluoride is a mineral that helps prevent tooth decay and helps keep your bones strong.

Iodine is a mineral found in some foods. The body needs iodine to make thyroid hormones. These hormones control the body’s metabolism and many other important functions. The body also needs thyroid hormones for proper bone and brain development during pregnancy and infancy. Getting enough iodine is important for everyone, especially infants and women who are pregnant.

Iron is a mineral that the body needs for growth and development. Your body uses iron to make hemoglobin, a protein in red blood cells that carries oxygen from the lungs to all parts of the body, and myoglobin, a protein that provides oxygen to muscles. Your body also needs iron to make some hormones.

Magnesium is a nutrient that the body needs to stay healthy. Magnesium is important for many processes in the body, including regulating muscle and nerve function, blood sugar levels, and blood pressure and making protein, bone, and DNA.

Manganese is a mineral that your body needs to stay healthy. Your body uses manganese to make energy and protect your cells from damage. Your body also needs manganese for strong bones, reproduction, blood clotting, and a healthy immune system.

Phosphorus is a mineral contained in each cell in our body. Most phosphorus is in the bones and teeth, and some is in your genes. Your body needs phosphorus to make energy and to carry out many important chemical processes.

Selenium is a nutrient that the body needs to stay healthy. Selenium is important for reproduction, thyroid gland function, DNA production, and protecting the body from damage caused by free radicals and from infection.

Sodium is an essential nutrient and is needed by the body in relatively small amounts (provided that substantial sweating does not occur) to maintain a balance of body fluids and keep muscles and nerves running smoothly.

Sodium attracts water, and a high-sodium diet draws water into the bloodstream, which can increase the volume of blood and subsequently your blood pressure.

Zinc is a nutrient that people need to stay healthy. Zinc is found in cells throughout the body. It helps your immune system fight off invading bacteria and viruses. Your body also uses zinc to make DNA (the genetic material in cells) and proteins. During pregnancy, infancy, childhood, and adolescence the body needs zinc to grow and develop properly. Zinc also helps wounds heal and is important for the proper sense of taste.

We're not quite Iron Man, but metals are intricately entwined with our bodies. They make vital functions like respiration, circulation and reproduction possible.

Cobalt, for instance, found at the core of vitamin B12, is key to making red blood cells, while iron allows those cells to ferry oxygen and other important chemicals to the body's tissues. Calcium not only strengthens bones but also plays a role in muscle, nerve function and blood clotting. Sodium and potassium help the heart and nerves communicate through electrical signals.

As the mercury-tainted Mad Hatter and headlines about lead poisoning attest, exposure to too much metal can be harmful. But not getting enough metal in the right places can make us sick, too. This is the case with conditions such as iron-deficiency anemia and osteoporosis. Read on to find out about National Institutes of Health-funded research into two metals that affect our health in unexpected ways.

Zinc Imbalance

Small amounts of zinc help ensure a proper immune response and healthy nervous system. Zinc also regulates the function of some genes, enables many proteins to carry out their vital roles and helps speed the chemical reactions that keep us alive. On the flip side, an imbalance of zinc has been linked to Alzheimer's disease, diabetes, prostate cancer and seizures.

Chemist Stephen Lippard of the Massachusetts Institute of Technology, who previously developed fluorescent chemical sensors that detect tiny amounts of zinc in the body, discovered with colleagues that zinc helps regulate communication between two types of brain cells in the hippocampus, the brain's center of learning and memory. Their findings suggest that zinc affects how we form memories and that high concentrations may contribute to epilepsy, where abnormal cell communication causes seizures. Scientists had seen zinc in specific hippocampal cells before but weren't sure what it did there.

Chaperoning Copper

Our bodies take great care to make sure metals go only where they need to and in exactly the right amount. Like teachers keeping an eye on students at the prom, so-called "chaperone" proteins protect metals (and the cell) from unwanted interactions while they safely deliver them to their cellular destinations. Problems can arise if chaperones don't do their jobs properly.

Take copper as an example. Malfunctioning chaperones that starve proteins of copper can lead to weak limbs, bone growths, seizures and kinky, brittle hair. That's what happens in people with Menkes syndrome. Copper that gets shut out of cells can accumulate in the bloodstream and cause a different disorder, Wilson's disease. High levels of copper can cause liver damage, kidney failure, coma and death. A copper chaperone that also ferries platinum can affect how cancer patients respond to cisplatin, a platinum-containing substance used in drugs to treat advanced testicular and ovarian cancers.

One way researchers are studying these copper-related disorders is by looking at the three-dimensional shapes of the chaperones. For instance, researchers at Northwestern University deciphered the intricate structure of a chaperone that inserts a molecule of copper into an enzyme whose defective forms have been linked to some inherited types of amyotrophic lateral sclerosis, also known as Lou Gehrig's disease. This structural knowledge, which offers insight into how the chaperone works and interacts with other molecules, deepens scientists' understanding of the disease and could provide a potential new treatment target.

More is better, right? Not when it comes to vitamins and minerals. Our bodies need these nutrients for many things, like breaking down the food we eat, making bones and DNA, helping muscles contract, and maintaining immunity. But there’s no reason to get more than you need, and some nutrients can be dangerous in large amounts.

Each vitamin and mineral has a recommended amount, which is what you should get each day for good health. Most of them also have what is called a “tolerable upper intake level” or UL. Getting more than the UL can cause health problems. Other vitamins and minerals appear to be safe at any dose, while a few have a UL only under certain circumstances.

Which vitamins and minerals fall into which category? Here’s the breakdown:

Nutrients with ULs: calcium, choline, copper, fluoride, iodine, iron, manganese, molybdenum, nickel, phosphorus, selenium, vitamin B6, vitamin C, vitamin D, and zinc

Stay under the UL each day for these nutrients to avoid health problems unless your healthcare provider recommends more. For example, very high doses of vitamin B6 can cause severe nerve damage and too much iron can be fatal.

The ULs for these nutrients include what you get from food, beverages, fortified foods (including many breakfast cereals), and dietary supplements. But it’s unlikely you’ll go above the UL from food and beverages alone.

Nutrients with ULs, but only from dietary supplements and fortified foods: folate, magnesium, niacin, and vitamin E

These vitamins and minerals, as found naturally in food and beverages, won’t cause any health problems. But they can if you get amounts above the UL from supplements or fortified foods.

One nutrient with a UL, but only for certain forms: vitamin A

Vitamin A exists in two main forms: preformed vitamin A—such as retinol and retinyl palmitate—in animal products (including meat, poultry, fish, and dairy products); and beta-carotene (in fruits, vegetables, and other plant foods). Dietary supplements can contain both forms.

Only preformed vitamin A has a UL because high amounts can cause health problems, such as birth defects during pregnancy and liver damage. Beta-carotene has no UL because high amounts don’t cause these problems.

Nutrients with no ULs: biotin, chromium, pantothenic acid, riboflavin, thiamin, vitamin B12, and vitamin K

These nutrients have no identified safety concerns, even at high doses. But there’s no reason to get more than recommended amounts unless your healthcare provider recommends it.

What’s the bottom line?

Most vitamins and minerals have upper limits known as ULs, so there is a range of safe intake between the recommended amounts and the ULs. Check the labels of dietary supplements and fortified foods to see the amounts of vitamins and minerals they contain. Be careful about doubling-up on supplements or taking more than the serving size listed on product labels. And talk with your healthcare provider to determine which supplements, if any, might be valuable for you.

Minerals help our bodies develop and function. They are essential for good health. Knowing about different minerals and what they do can help you to make sure you get enough of the minerals that you need.

Antioxidants

Antioxidants are substances that may prevent or delay some types of cell damage. Examples include beta-carotene, lutein, lycopene, selenium, and vitamins C and E. They are found in many foods, including fruits and vegetables. They are also available as dietary supplements. Most research has not shown antioxidant supplements to be helpful in preventing diseases.

Calcium

Calcium is a mineral found in many foods. Almost all calcium is stored in bones and teeth to help make and keep them strong. Your body needs calcium to help muscles and blood vessels contract and expand, and to send messages through the nervous system. Calcium is also used to help release hormones and enzymes that affect almost every function in the human body.

Daily Value (DV)

The Daily Value (DV) tells you what percentage of a nutrient one serving of that food or supplement provides compared to the recommended amount.

Dietary Supplements

A dietary supplement is a product you take to supplement your diet. It contains one or more dietary ingredients (including vitamins; minerals; herbs or other botanicals; amino acids; and other substances). Supplements do not have to go through the testing that drugs do for effectiveness and safety.

Electrolytes

Electrolytes are minerals in body fluids. They include sodium, potassium, magnesium, and chloride. When you are dehydrated, your body does not have enough fluid and electrolytes.

Iodine

Iodine is a mineral found in some foods. Your body needs iodine to make thyroid hormones. These hormones control your body’s metabolism and other functions. They are also important for bone and brain development during pregnancy and infancy.

Iron

Iron is a mineral. It is also added to some food products and is available as a dietary supplement. Iron is a part of hemoglobin, a protein that transports oxygen from the lungs to the tissues. It helps provide oxygen to muscles. Iron is important for cell growth, development, and normal body functions. Iron also helps the body make some hormones and connective tissue.

Magnesium

Magnesium is a mineral naturally present in many foods, and is added to other food products. It is also available as a dietary supplement and present in some medicines. It helps your body regulate muscle and nerve function, blood sugar levels, and blood pressure. It also helps your body make protein, bone, and DNA.

Minerals

Minerals are those elements on the earth and in foods that our bodies need to develop and function normally. Those essential for health include calcium, phosphorus, potassium, sodium, chloride, magnesium, iron, zinc, iodine, chromium, copper, fluoride, molybdenum, manganese, and selenium.

Multivitamin/Mineral Supplements

Multivitamin/mineral supplements contain a combination of vitamins and minerals. They sometimes have other ingredients, such as herbs. They are also called multis, multiples, or simply vitamins. Multis help people get the recommended amounts of vitamins and minerals when they cannot or do not get enough of these nutrients from food.

Phosphorus

Phosphorus is a mineral that helps keep your bones healthy. It also helps keep blood vessels and muscles working. Phosphorus is found naturally in foods rich in protein, such as meat, poultry, fish, nuts, beans, and dairy products. Phosphorus is also added to many processed foods.

Potassium

Potassium is a mineral that your cells, nerves, and muscles need to function properly. It helps your body regulate your blood pressure, heart rhythm and the water content in cells. It also helps with digestion. Most people get all the potassium they need from what they eat and drink. It is also available as a dietary supplement.

Recommended Dietary Allowance (RDA)

Recommended Dietary Allowance (RDA) is the amount of a nutrient you should get each day. There are different RDAs based on age, gender, and whether a woman is pregnant or breastfeeding.

Selenium

Selenium is a mineral that the body needs to stay healthy. It is important for reproduction, thyroid function, and DNA production. It also helps protect the body from damage caused by free radicals (unstable atoms or molecules that can damage cells) and infections. Selenium is present in many foods, and is sometimes added to other foods. It is also available as a dietary supplement.

Sodium

Table salt is made up of the elements sodium and chlorine - the technical name for salt is sodium chloride. Your body needs some sodium to work properly. It helps with the function of nerves and muscles. It also helps to keep the right balance of fluids in your body.

Zinc

Zinc, a mineral that people need to stay healthy, is found in cells throughout the body. It helps the immune system fight off invading bacteria and viruses. The body also needs zinc to make proteins and DNA, the genetic material in all cells. During pregnancy, infancy, and childhood, the body needs zinc to grow and develop properly. Zinc also helps wounds heal and is important for our ability to taste and smell. Zinc is found in a wide variety of foods, and is found in most multivitamin/mineral supplements.

Q. Where can I find out how much of each vitamin and mineral I need?

A. To get a list of all vitamins and minerals and how much you need, check out the free online tool from the U.S. Department of Agriculture. Just input a few pieces of information about yourself including your age, height, and weight. You also can get a list of your daily calorie, protein, and other nutritional needs. Keep in mind that the amounts of vitamins and minerals you need include everything you get from food and beverages—you may or may not need a dietary supplement to achieve these amounts. Talk with your health care provider to help you determine which supplements, if any, might be valuable for you.

Q. How can I get more information about a particular dietary supplement such as whether it is safe and effective?

A. Scientific evidence supporting the benefits of some dietary supplements (for example, vitamins and minerals) is well established for certain health conditions, but others need further study.

Research studies in people to prove that a dietary supplement is safe are not required before the supplement is marketed, unlike for drugs. This is due to the way dietary supplements are regulated by the U.S. Food and Drug Administration (FDA). It is the responsibility of dietary supplement manufacturers/distributors to ensure that their products are safe and that their label claims are truthful and not misleading. If the FDA finds a supplement to be unsafe once it is on the market, only then can it take action against the manufacturer and/or distributor, such as by issuing a warning or requiring the product to be removed from the marketplace.

The manufacturer does not have to prove that the supplement is effective, unlike for drugs. The manufacturer can say that the product addresses a nutrient deficiency, supports health, or reduces the risk of developing a health problem, if that is true. If the manufacturer does make a claim, it must be followed by the statement “This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.”

Dietary supplements are not intended to treat, diagnose, mitigate, prevent, or cure disease. In some cases, dietary supplements may have unwanted effects, especially if taken before surgery or with other dietary supplements or medicines, or if you have certain health conditions. Supplements should not replace prescribed medications or the variety of foods important to a healthful diet.

Do not self-diagnose any health condition. Work with your health care provider to determine how best to achieve optimal health. Also, check with your health care provider before taking a supplement, especially if you take any medicines or other dietary supplements or if you have any health conditions.

Q. Where can I find information about the use of dietary supplements for a particular health condition or disease?

A. Scientific evidence supporting the benefits of some dietary supplements (for example, vitamins and minerals) is well established for certain health conditions, but others need further study. Whatever your choice, supplements should not replace prescribed medications or the variety of foods important to a healthy diet.

Dietary supplements are not intended to treat, diagnose, mitigate, prevent, or cure disease. In some cases, dietary supplements may have unwanted effects, especially if taken before surgery or with other dietary supplements or medicines, or if you have certain health conditions.

Do not self-diagnose any health condition. Work with your health care provider to determine how best to achieve optimal health. Also, check with your health care provider before taking a supplement, especially if you take any medicines or other dietary supplements or if you have any health conditions.

Q. What does the Supplement Facts label on a dietary supplement tell me?

A. All products labeled as dietary supplements carry a Supplement Facts label that is similar to the Nutrition Facts label found on food products. It lists the active ingredients and their amounts, plus other added ingredients like fillers, binders, and flavorings. It also gives a suggested serving size, but you and your health care provider might decide that a different amount is more appropriate for you.

In the Supplement Facts label, the amounts of vitamins, minerals, and other nutrients like dietary fiber are listed as a percentage of the Daily Value (%DV). Each nutrient has one DV that applies to all people aged 4 and older. For example, the DV for vitamin C is 90 milligrams (mg) and the DV for the B-vitamin biotin is 30 micrograms (mcg).

The %DV allows you to see how much a product contributes to your approximate daily needs for that nutrient. For example, if a supplement provides 50% of the DV for calcium, it contributes about half of your daily needs for calcium.

Q. What is the difference between the RDA and DV for a vitamin or mineral?

A. Many terms are used when referring to either the amount of a particular nutrient (such as calcium or vitamin D) you should get or the amount in a food or dietary supplement. The two most common are the Recommended Dietary Allowance (RDA) and the Daily Value (DV). These terms can be confusing.

RDAs are recommended daily intakes of a nutrient for healthy people. They tell you how much of that nutrient you should get on average each day. RDAs are developed by the Food and Nutrition Board of the National Academies of Sciences, Engineering, and Medicine. They vary by age, sex, and whether a woman is pregnant or breastfeeding; so there are many different RDAs for each nutrient.

DVs, established by the U.S. Food and Drug Administration (FDA), are used on food and dietary supplement labels. For each nutrient, there is one DV for all people ages 4 years and older. Therefore, DVs aren’t recommended intakes, but suggest how much of a nutrient a serving of the food or supplement provides in the context of a total daily diet. DVs often match or exceed the RDAs for most people, but not in all cases.

DVs are presented on food and supplement labels as a percentage. They help you compare one product with another. As an example, the %DV for calcium on a food label might say 20%. This means it has 260 milligrams (mg) of calcium in one serving because the DV for calcium is 1,300 mg/day. If another food has 40% of the DV for calcium, it’s easy to see that it provides much more calcium.

Q. What are the upper limits for vitamins and minerals?

A. Our bodies need vitamins and minerals for many things, like breaking down the food we eat, making bones and DNA, helping muscles contract, and maintaining immunity. But there’s no reason to get more than you need, and some nutrients can be dangerous in large amounts.

Each vitamin and mineral has a recommended amount, which is what you should get each day for good health. Most of them also have what is called a “tolerable upper intake level” or UL. Getting more than the UL can cause health problems. Other vitamins and minerals appear to be safe at any dose, while a few have a UL only under certain circumstances.

Which vitamins and minerals fall into which category? Here’s the breakdown:

• Nutrients with ULs: calcium, choline, copper, fluoride, iodine, iron, manganese, molybdenum, nickel, phosphorus, selenium, vitamin B6, vitamin C, vitamin D, and zinc

  Stay under the UL each day for these nutrients to avoid health problems unless your health care provider recommends more. For example, very high doses of vitamin B6 can cause severe nerve damage and too much iron can be fatal. The ULs for these nutrients include what you get from food, beverages, fortified foods (including many breakfast cereals), and dietary supplements. But it’s unlikely you’ll go above the UL from food and beverages alone.

• Nutrients with ULs, but only from dietary supplements and fortified foods: folate, magnesium, niacin, and vitamin E

  These vitamins and minerals, as found naturally in food and beverages, won’t cause any health problems. But they can if you get amounts above the UL from supplements or fortified foods.

• One nutrient with a UL, but only for certain forms: vitamin A

  Vitamin A exists in two main forms: preformed vitamin A—such as retinol and retinyl palmitate—in animal products (including meat, poultry, fish, and dairy products); and beta-carotene (in fruits, vegetables, and other plant foods). Dietary supplements can contain both forms.

  Only preformed vitamin A has a UL because high amounts can cause health problems, such as birth defects during pregnancy and liver damage. Beta-carotene has no UL because high amounts don’t cause these problems.

• Nutrients with no ULs: biotin, chromium, pantothenic acid, riboflavin, thiamin, vitamin B12, and vitamin K

  These nutrients have no identified safety concerns, even at high doses. But there’s no reason to get more than recommended amounts unless your health care provider recommends it.