Whether you fill your reusable water bottle at the kitchen sink, grab a sports drink at the gym, or enjoy a glass of cold milk from the refrigerator, you are consuming minerals. Sodium, potassium, calcium, magnesium, and other minerals are found in many of the foods and beverages we consume every day. Although minerals make up only a small percentage of body weight, they are essential for life. They regulate fluid balance, support muscle contraction, build strong bones, and help thousands of chemical reactions occur throughout the body.

Unlike vitamins, which are organic compounds, minerals are inorganic elements that come from soil, water, and rocks. Plants absorb minerals from the soil in which they grow, and animals obtain them by eating plants or other animals. Humans obtain minerals by consuming both plant and animal foods.

Minerals are classified according to the amount the body requires. Major minerals are needed in amounts greater than 100 milligrams per day, whereas trace minerals are needed in amounts less than 100 milligrams. Although trace minerals are required in much smaller quantities, they are just as essential for good health.

Figure 9.2 shows the seven major minerals discussed in this chapter. They are found in a wide variety of foods. For example, milk and yogurt provide calcium and phosphorus, while potatoes, bananas, beans, and leafy green vegetables are good sources of potassium and magnesium. Whole grains, nuts, meats, seafood, and legumes also supply important minerals.

Trace minerals include zinc, copper, selenium, iodine, chromium, fluoride, manganese, and molybdenum. Although deficiencies are less common, inadequate intake can still lead to serious health problems.

One well-known example is iodine deficiency. Before iodized salt became widely available in 1924, iodine deficiency and goiter were common in parts of the United States, particularly in the Great Lakes and Appalachian regions. Adding iodine to table salt virtually eliminated this deficiency, making salt iodization one of the nation’s most successful public health nutrition interventions. ^[1]

Bioavailability of Minerals Varies

Knowing how much of a mineral is present in food is only part of the story. Equally important is how much of that mineral your body can absorb and use, a concept known as bioavailability. Unlike many vitamins, minerals are often absorbed less efficiently. Plant foods may contain naturally occurring compounds such as oxalates and phytates that bind to certain minerals and reduce their absorption. As a result, some minerals are generally more readily absorbed from animal foods than from plant foods.

Mineral absorption is also influenced by other nutrients and by the body’s needs. For example, vitamin C enhances iron absorption, while vitamin D promotes calcium absorption. In contrast, excessive zinc intake can interfere with the absorption of iron and copper. In general, the body absorbs a smaller percentage of a mineral when dietary intake is high and a larger percentage when intake is low, helping maintain mineral balance.

Certain health conditions can further reduce mineral absorption. Gastrointestinal disorders such as Crohn's disease, diseases that affect kidney function, and the normal aging process can increase the risk of mineral deficiencies.

Attributions

This section is an adaptation of “Introduction” in Human Nutrition: 2020 Edition by University of Hawai‘i at Mānoa Food Science and Human Nutrition Program licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.