Many people think minerals and vitamins are the same, but they are not. Minerals, like vitamins, are important nutrients found in foods. The main difference is that vitamins are organic substances (meaning that they contain the element carbon) and minerals are inorganic substances. Minerals are needed for many things in addition to eating them in the form of nutrients in foods. The iron and copper in cookware or tools are the same minerals found in food. That is why cooking in a cast iron skillet can provide iron in the diet. When cooking food in an iron skillet, a little bit of the iron comes off and mixes with the food. People can absorb and use it just like iron that is already in food. Minerals are the most permanent part of living things. They do not burn, and, in fact, they can be found in the ashes of something that has burned.
There are two groups of minerals, major minerals and trace minerals. Major minerals are needed in the diet in amounts of 100 milligrams (mg) or more each day. A milligram is a very small amount. It is one thousandth of a gram, and there are 28 grams in an ounce. The major minerals are calcium, phosphorus, magnesium, sulfur, potassium, sodium, and chloride. We need the trace minerals in smaller amounts (less than 100 mg each day). Some trace minerals are iron, iodine, zinc, fluoride, selenium, copper, chromium, manganese, and molybdenum.
The body contains many different minerals. Minerals by themselves are inactive chemical elements, like the iron in a pan or calcium in a rock. But in the body, calcium is used to make the bones and teeth, and iron is used to make the hemoglobin in red blood cells. The body uses this iron to carry oxygen to its cells. Additional minerals help in many other body processes:
Sodium, potassium and chloride are minerals that are called “electrolytes.” In the body, they work to maintain water balance and provide the correct pressure between cells and their surrounding fluids. Sodium and chloride are the major electrolytes in the fluid that surrounds body cells. Potassium is the primary electrolyte within body cells. Table salt is the most common food that contains both chloride and sodium. Most people consume more than enough sodium. In fact, many health experts believe that consuming too much sodium from salt and a high salt intake may contribute to high blood pressure in people who are “sodium sensitive.”
Minerals can build up in the body, and they can be toxic and cause harmful effects. To avoid this possibility, never take individual mineral supplements unless your doctor prescribes them. Also, make sure to keep supplements that contain minerals in a safe place so children cannot accidentally eat them. A young child can get iron toxicity from taking several adult iron supplements at one time.
Minerals are present in foods in different amounts, and all foods do not contain the same minerals. This is why people need to eat a variety of foods from all of the food groups. The Table 1 shows which minerals are found in the different USDA Daily Food Plan food groups