Minerals are substances composed of only one type of atom. They are inorganic. Minerals do not contain the carbon, hydrogen, and oxygen atoms found in organic compounds. Minerals occur naturally in nonliving things, such as rocks and metal ores. Although minerals also are present in plants and animals, they are imported – plants absorb minerals from the soil and animals obtain minerals by eating plants.
Minerals, essential for human life, are classified either as major minerals or trace elements. The difference between the two is the amount of the mineral that is stored in our body and how much is needed to take in to maintain a steady supply.
Most of the calcium in the body is packed into the bones and teeth. Calcium is also present in extracellular ﬂuid, the liquid around body cells, where it performs the following functions:
- Regulating ﬂuid level by controlling the flow of water in and out of cells.
- Enabling cells to send messages back and forth from one to another.
- Keeping muscles moving easy and preventing cramping.
The best food sources of calcium are milk and dairy products as well as fish, such as canned sardines and salmon. Calcium also is found in dark green leafy vegetables, but the calcium in plant foods is bound into compounds that are less easily absorbed by our body.
Phosphorus is essential for strong teeth and bones. Phosphorus also enables a cell to transmit the genetic code to the new cells created when a cell divides and reproduces. Phosphorus, also:
- Is vital for metabolizing carbohydrates, ferrying fats and fatty acids among tissues and organs and synthesizing proteins.
- Helps maintain the pH balance of blood, i.e. keeps it from being too acidic or too alkaline.
- Is part of myelin, the fatty piece that surrounds and protects each nerve cell.
Phosphorus is present in almost everything we eat. The best sources, though, are high-protein foods, such as meat, eggs, fish, poultry, and milk. Grains, seeds, nuts and dry beans also provide respectable amounts.
Our body uses magnesium to make body tissues, especially bone. Magnesium also is part of more than 300 different enzymes that trigger chemical reactions throughout our body. Magnesium is used to:
- Send messages between cells.
- Move nutrients in and out of cells.
An adequate supply of magnesium also is heart-healthy as it enables the body to convert food to energy using less oxygen.
Plant foods such as bananas, nuts, grains, dark green fruits and vegetables, whole seeds and beans are excellent sources of magnesium.
Trace elements are minerals but present in our body in smaller amounts.
Iron is an essential constituent of myoglobin and hemoglobin, two proteins that store and transport oxygen. Hemoglobin is what makes the red blood cells red. Myoglobin is present in muscle tissue. Iron is also part of various enzymes.
The best food sources of iron are organ meats (kidneys, liver, heart)), egg yolks, red meat, wheat germ, and oysters. These foods contain heme iron, a form of iron that our body easily can absorb.
Zinc protects nerve and brain tissue, bolsters the immune system and is essential for healthy growth. Zinc is part of the enzymes and hormones, such as insulin, that metabolize food. The largest quantities of zinc in the male human body are in the testes, where zinc is used in making a continuous supply of testosterone.
Good sources of zinc are meat, liver, oysters and eggs. Zinc is also plentiful in nuts, beans, pumpkin and sunflower seeds, wheat germ and whole-grain products. The zinc in plants occurs in compounds that our body absorbs less efficiently than the zinc in foods from animals.
Iodine is a component of the thyroid hormones thyroxine and triiodothyronine, which help regulate cell activities. These hormones are also essential for protein synthesis, tissue growth, including the formation of healthy nerves and bones, and reproduction. The best natural sources of iodine are seafood and plants grown near or in the ocean. However, many people get needed iodine from iodized salt.
The best sources of selenium are seafood, meat and organ meats (kidney, liver), eggs, and dairy products.
Copper is an antioxidant found in enzymes that deactivate free radicals and make it possible for our body to use iron. Copper also may play a role in slowing the aging process by decreasing the incidence of protein glycation, a reaction in which sugar molecules hook up with protein molecules in the bloodstream, twist the protein molecules out of shape, and make them unusable.
In addition copper:
- Promotes the growth of strong bones.
- Prevents our hair from turning gray prematurely.
- Protects the health of nerve tissue.
Sources of copper are organ meats (liver, heart), nuts, seafood, and dried beans, including cacao beans.
Most of the manganese in our body is in the glands (pituitary, mammary, pancreas), organs (kidneys, intestines, liver), and bones. Manganese is an essential constituent of the enzymes that metabolize carbohydrates and synthesize fats (including cholesterol). Manganese is important for a healthy reproductive system.
Sources of manganese include whole grains, fruits, cereal products, vegetables and tea.
Our body stores fluoride in bones and teeth. Although researchers still have some questions about whether fluoride is an essential nutrient, it is clear that fluoride hardens dental enamel, reducing risk of getting cavities.
All soil, ground water, plants and animal tissue contain small amounts of fluoride, but the most steady supply of fluoride comes from ﬂuoridated drinking water.
Small amounts of chromium are essential for several enzymes that is needed to metabolize fat. Chromium also partners with glucose tolerance factors, a group of chemicals that enables insulin to regulate our use of glucose, the end product of metabolism and the basic fuel for every body cell.
Molybdenum is part of several enzymes that metabolize proteins. Sources of molybdenum are grains and beans. Cows eat grains, so milk and cheese have some molybdenum. Molybdenum also leeches into drinking water from surrounding soil. The molybdenum content of plants and drinking water depends entirely on how much molybdenum is in the soil.
- Calcium. Without enough calcium, an adult’s bones lose minerals and weaken, and a child’s bones and teeth will not grow strong and straight. Calcium functions with other nutrients. To protect against deficiency, adequate amounts of vitamin D is also needed. Vitamin D allows the body to absorb the calcium received from food or supplements.
- Iron. Lacking sufficient iron, our body can not make the hemoglobin required to carry energy-sustaining oxygen to every tissue. As a result, a feeling of tiredness and weakness occurs.
- Zinc. An-adequate supply of zinc is vital for making testosterone. Men who do not get enough zinc may be temporarily infertile. Zinc deficiency leads to loss of appetite and the ability to taste food. It may also weaken the immune system, increasing the risk of infections. Wounds heal more slowly.
- Iodine. A moderate iodine deficiency leads to goiter (a swollen thyroid gland) and reduced production of thyroid hormones. A more severe deficiency early in life may cause a form of mental and physical retardation, called cretinism.