Minerals are found the body's fluids and tissues and make up approximately four percent of the body's total weight. Working in conjunction with vitamins, enzymes, hormones, and other substances, minerals play an important role in numerous biological functions, including the growth and maintenance of bones and teeth, muscle contraction, nerve transmission, blood formation, energy production, fluid regulation, macronutrient metabolism, acid-alkaline balance (pH), and various other enzymatic reactions.

Nutrient minerals are classified according to how much of the body's total weight they comprise. Macrominerals comprise at least .01 percent of body weight, while trace or microminerals constitute less than .01 percent. An adequate supply of both macro- and trace minerals are equally important for optimal health, however.

Macrominerals include calcium, chloride, magnesium, phosphorus, potassium, and sodium, while trace minerals include chromium, cobalt, copper, iodine, iron, manganese, molybdenum, selenium, sulphur, and zinc.

Calcium is the most plentiful mineral in the human body, with approximately 99 percent of it occurring in bone tissue, and the remaining one percent being used for a variety of other functions, including blood clotting, muscle contracion, and nerve function. Healthy teeth and bones both depend on adequate calcium supply, and calcium also contributes to healthy skin, helps regulate cardiovascular function and blood pressure levels, aids in the metabolism of iron, and is required for proper cell division.

Calcium must be daily supplied to the body through the diet or supplementation. The best food soruces of calcium include milk, yogurt, cheese, cottage cheese, dark green leafy vegetables, broccoli, turnip and collard greens, salmon, sardines, canned fish, almonds, and brazil nuts. The standard American diet is estmated to supply only one-third of our daily calcium needs.

Signs of calcium deficiency include bone and skeletal problems (most notably osteoporosis and fracture), anxiety, brittle nails, depression, insomnia, muscle cramps and twitcthing, and diminished nerve function. Calcium is best supplemented as part of a multivitamin/multimineral formula.

Note: Excessive amounts of calcium over time can lead to kidney stones and soft tissue calcification, and possibly contribute to atherosclerosis.

Chloride is an essential part of hydrochloric acid (HCl), a vital stomach digestive acid, and also plays a role in regulating the body's acid-balance. It is also useful in helping the liver eliminate toxins, and for transporting carbon dioxide to the lungs for excretion. Among the best food sources of chloride are common table salt, sea salt, seaweeds, celery, lettuce, and tomatoes. The standard American diet contains more than enough chloride due to its hig salt content.

Chloride loss can easily occur folloiwng bouts of diarrhea or vomiting, as well as periods of profuse perspiration. Overall, however, chloride deficiencies are rare, with the most common symptoms being acid-base imbalances and over alkalinity of body fluids.

Magnesium acts as a muscle relaxant in the body, and is involved in hundreds of enyzmatic reactions. Approximately 65 percent of the body's magnesium supply is contained in the bones and teeth, with the second highest concentration occurring in the muscles. The remaining magnesium supply is found in the blood and other body fluids.

In addition to its ability to relax smooth and skeletal muscles, magnesium is an important nutrient for the heart, especially in preventing spasms of the coronary arteries, which can cause heart attacks. It is also needed for energy production, the maintenance and repair of cells, healthy cell division, proper nerve transmission, hormone regulation, and the metabolism of proteins and nucleic acids.

Foods souces of magnesium are primarily plants rich in chlorophyll, particularly dark green vegetables. Nuts, seeds, legumes, tofu, wheat germ, milet, brown rice, apricot, and avocado are other good souces.

Magnesium deficiency is now considered more common than many physicians realize, due to factors such as poor diet, overcooking, deficient soil, and the overuse of alcohol. Deficiency symptoms include depression, fatigue, gastrointestinal disorders, high blood pressure, irregular heartbeat, memory problems, mood swings, imapired motor skills, muscle spasm, nausea, and tetany.

Phosphorus ranks second behind calcium as the body's most abundant mineral. It is found in every cel of the body, but primarily (approximately 85 percent) in the bones and teeth. In addition to contributing to bone and teeth structure, phosphorus helps form DNA and RNA, catalyzes B-complex vitamins, is involved in cellular communication and numerous enzymatic reactions, and helps produce energy and increase endurance.

The best food souces of phosphorus are protein foods, such as meats, fish, poultry, eggs, milk, and cheese. Other good sources include nuts, seeds, wheat germ, whole grains, and Brewer's yeast. The standard American diet can be over-high in its phosphorus content, especially with regard to soda, which can contain up to 500 mg of phosphorus per serving and create calcium-phosphorus imbalance.

Because phosphorus is contained in all animal foods, phosphorus deficiency is rare. Overuse of antacids, excessive calcium intake, and lack of vitamin D can all result in phosphorus deficiency, however. Signs of deficiency include anxiety, arthritis, impaired bone growth, irritability, and weakness.

Potassium, along with chloride and sodium, is an electrolyte, or essential body salt, that conducts electric current throughout the body. Approximately 98 percent of the body's potassium supply is contained inside the walls of the cells, where it regulates water and acid-base balance. It is vital to cellular integrity and fluid balance, and plays an important role in nerve function. It also helps metabolize proteins and carbohydrates, aids in energy production, and helps regulate heartbeat.

Optimum food sources of potassium are fresh fruits and vegetables, with bananas being a particularly rich source.Whole grains, seeds, nuts, wheat germ, salmon, and sardines are also good food sources.

Potassium deficiencies are fairly common, particularly among older people and people suffering chronic disease. Diarrhea, diabetes, fasting, and the overuse of diuretics and laxatives all contribute to potassium loss. Deficiency symptoms include arrythmia, depression, fatigue, high blood pressure, hyperglycemia, impaired growth, mood swings, and unhealthy changes in the nervous system.

Sodium is also present in all of the body's cells, as well as the blood and other body fluids. Approximately 60 percent of the body's sodium content is contained in extracellular (outside the cells) fluids, with 10 percent found inside the cells, and the remainder occurring in the bones. Like potassium, sodium helps maintain the body's fluid balance within and without the cells, thereby regulating the body's acid-base balance. It also helps transport carbon dioxide, and plays a role in muscle contraction and nerve transmission. In addition, sodium is involved in the production of hydrochloric acid, and helps transport amino acids into the bloodstream to all the cells of the body.

Nearly all foods contain some degree of sodium, with seafood, beef, and poultry containing particularly high amounts. The primary dietary source of sodium is table salt, and sodium is also present in significant amounts in most canned and processed foods.

Chronic sodium deficiency is rare, although sodium loss can occur because of diarrhea, vomiting, profuse perspiration due to athletics and other strenuous activity, and the overuse of diuretics. Problems related to excessive sodium intake are far more common among people who eat the standard American diet, and can lead to high blood pressure and PMS, among other conditions. Deficiency symptoms include dehydration, low blood pressure, muscle cramping and twitching, and muscle weakness.

Chromium is an essential component of glucose tolerance factor (GTF), which enhances insulin function, making it vital for proper carbohydrate metabolism and for regulating blood sugar levels. By improving how glucose is transported into the cells, chromium and GTF are also important for energy production. Research suggests that chromium may also be useful for regulating body cholesterol levels.

One of the best food sources of chromium is Brewer's yeast. Other food sources include wholegrain breads and cereals, wheat germ, eggs, meats, and shellfish. Chromium deficiency is quite common, especially in the United States, due to mineral-depleted soils and and over-reliance of refined and processed foods. In addition, many people have problems absorbing chromium, particularly as they age. Deficiency symptoms include diabtetes-like blood sugar problems caused by a reduction in peripheral tissue sensitivity to glucose. Anxiety, fatigue, and impaired cholesterol metabolism are also associated with a lack of chromium in the diet.

Cobalt, in addition to being a component of cobalamin (vitamin B12), plays an essential role in the production of red blood cells, and is involved in a number of enzymatic reactions. Adequate vitamin B12 intake normally provides sufficient amounts of cobalt to the body. Food sources include beet greens, cabbage, figs, legumes, lettuce, liver, and seafish and sea vegetables. Cobalt deficiencies are similar to those caused by a lack of B12, including anemia and nerve damage.

Copper is present in al body tissues, but is particularly concentrated in the liver and brain. It aids in the manufacture of collagen and hemoglobin, and, along with iron, is necessary for the synthesis of oxygen in red blood cells. It also acts as an antioxidant, increases iron absorption, and serves as a catalyst for a variety of enzymatic reactions.

The best food sources of copper include dark green leafy vegetables, eggs, organ meats, poultry, nuts, shellfish, and wholegrain breads and cereals. Although dangerous copper deficiencies are rare, less serious copper deficiencies are more common. Symptoms include anemia, dermatitis, diarrhea, edema, fatigue, impaired collagen production, labored respiration, and tissue and blood vessel damage.

Iodine is essential for healthy thyroid function due to the role it plays in the production of thyroid hormones. In this role, it is helps regulate metabolism and energy production in the body, as well as cellular oxidation. Since thyroid hormones plays a role in all body functions, iodine is of vital importance to overall health, yet iodine deficiency is estimated to affect at least 200 million people worldwide, due in part to depleted soil conditions.

The best food sources of iodine are iodized salt, followed by seafood and seaweed. Deficiency symptoms include fatigue, goiter, hypothyroidism, decreased libido, impaired mental functioning, impaired metabolism, and weight gain.

Iron is present all the cells of the body, usually in combination with protein. Iron's primary function is the manufacture of hemoglobin, which is integral to the transport of oxygen throughout the body. Iron is also essential for healthy immune function and energy production. Research suggest it may additionally play a role in protecting cells and tissues from damage due to oxidation.

Among the best food sources of iron are beef, Brewer's yeast, kelp, molasses, organ meats, dark green leafy vegetables, legumes, oysters, and sardines. In supplement form, it is best taken with vitamin C, which aids in its assimilation.

Women, especially during their child-bearing years, require more iron than men, particularly during pregnancy and menstruation. Approximately 10 percent of all women in the Western world are estimated to be iron-deficient. Children and the elderly are also more prone to iron deficiency. Deficiency symptoms include iron- deficiency anemia, dizziness, fatigue, headache, learning disabilities, lowered immunity, and impaired sleep.

Manganese supports a variety of enzymatic reactions in the body, and is essential for proper brain function and the overall health of the nervous system. it also helps metabolize proteins and carbohydrates, and is required for cholesterol and fatty acid synthesis, as well as collagen formation. The best food sources of manganese are green leafy vegetables (especially spinach), nuts, organ meats, and wholegrain breads and cereals.

Manganese deficiency in humans is rare. Deficiency symptoms include dizziness, hearing problems, and weakness.

Molybdenum, along with copper, is necessary for the body's proper utilization of iron, and aids in metabolizing carbohydrates. It also helps the body detoxify potentially toxic sulfites commonly used to preserve food. Molybdenum deficiency is rare, and is primarily caused by eating foods grown in molybdenum-deficient soils or a diet high in refined and processed foods. Deficiency symptoms include anemia and a greater risk of dental caries. Excessive molybdenum intake can also result in various symptoms, including goutlike symptoms and elevated uric acid levels.

Selenium in recent decades has become recognized as an important antioxidant capable of performing many of the same antioxidant functions as vitamin E, including protecting cellular membranes from free radical damage, and minimizing the risk of cardiovascular disease. In addition, selenium aids liver function, assists in the manufacture of proteins, helps neutralize heavy metals and other toxic substances, and acts as an anticarcinogen.

The best food sources of selenium include Brewer's yeast, wheat bran and wheat germ, Brazil nuts, organs meats, and seafood. A number of plant foods, such as broccoli, onions, and tomatoes, can also be good sources, depending on the soil content in which they are grown.

Symptoms of selenium deficiency can mimic those common to a lack of vitamin E and also result in an increased risk of cancer, cardiovascular disease, high blood pressure, and stroke.

Sulphur occurs in all cells and body tissues, especially those high in protein content. It is a necessary nutrient for collagen formation, and is involved in the synthesis of protein. In addition, sulfur helps maintain the health of hair, skin, and nails. It also plays a role in a number of enzymatic reactions, and contributes to the process of cellular respiration.

The best food sources of sulfur are those high in protein, such as eggs, fish, legumes, meat, milk, and poultry. Plant food sources include brussel sprouts, cabbage, garlic, onions, and turnips.

No deficiency symptoms for sulfur have been established.

Zinc is one of the most important mineral nutrients and is necessary for the proper function of over 200 enyzmatic reactions in the body. It also acts as a potent antioxidant and detoxifier, and is essential for growth and development, healthy body tissues, regulation of insulin, proper immune function, and, in men, the heath of the prostate gland. In addition, zinc plays a vital role in cellular membrane structure and function, and helps maintain adequate levels of vitamin A in the body.

The best food sources of zinc include herring, shellfish (especially oysters), egg yolk, milk, and beef and other meats. Whole grain breads and cereals, nuts, and Brewer's yeast are other food sources. Zinc deficiency is quite common, with vegetarians, because they avoid animal foods, having a particularly high risk unless they consume adequate amounts of whole grains and other non-animal foods containing zinc.

Symptoms of zinc deficiency include impaired energy production and protein synthesis, and suboptimal formation of collagen. Other symptoms include dermatitis, fatigue, greater risk of environmental sensitivity, hair loss, impaired immune function, diminished libido, and greater risk of prostatic conditions.

Note: Zinc can interfere with copper absorption, therefore zinc and copper supplements should be taken apart from each other.