The 9 Trace Minerals in detail

Chromium

Chromium: Chromium is a popular dietary supplement, yet despite the hype, its proposed benefits have not been supported by the results of intervention trials. There is essentially no credible evidence that it promotes weight loss, or that it improves muscle mass with resistance training. Perhaps even more surprising, recent studies have failed to conclusively demonstrate that chromium can enhance the ability of insulin to control blood glucose, and no progress has been made in identifying the means by which chromium might exert its biological affects. some experts now question chromium's designation as an essential nutrient. Functions: Food Sources: Recommendations: Deficiency: chromium deficiency in humans has been observed only in hospitalized patients who had been receiving 100% of all nutrients intravenously for an extended period. Toxicity/UL:

Copper

Copper: Functions: copper functions as a co-factor in oxygen-dependent enzymes in the body. Though there are only about a dozen copper-containing human enzymes, they participate in a variety of critical physiological processes, including but not limited to, energy metabolism, formation of connective tissue, regulation of iron storage and transport, and antioxidant functions. Copper may play a role in slowing the progression of age-related macular degeneration, which is responsible for causing severe vision loss in the elderly. Food Sources: Although copper is found in a wide variety of foods, it is highest in organ meats, shellfish, nuts, seeds, mushrooms, chocolate, and legumes. *Cashews (dry-roasted): 1,259 mcg *King crab (cooked): 1,005 mcg *Pistachios (dry roasted): 733 mcg *Clams (cooked): 585 mcg *Dark Chocolate (70-85%): 500 mcg *Avocado (raw, pureed): 358 mcg *Mushrooms (cooked): 343 mcg *MUESLI cereal: 31 mcg *Brown rice (cooked): 263 mcg *Hot milk chocolate: 258 mcg *Black beans (cooked): 249 mcg *Lentils (cooked): 248 mcg *Raisins: 231 mcg *Sweet Potato (mashed): 154 mcg *Ground beef (90%): 77 mcg *Whole wheat bread (1 slice): 73 mcg Recommendations: The RDA for copper is 900 micrograms per day in adults. Approximately 55% to 75% of dietary copper is absorbed, which is much more efficient than other trace minerals. Deficiency: Deficiencies of copper from low dietary intakes are rare in the United States as most of the population meets or exceeds the RDA for copper. However, deficiencies that are secondary to other factors are more common. Copper deficiencies are somewhat common in people who have gastric bypass surgery to treat obesity, as well as in those with other conditions that cause nutrient malabsorption. Excessive zinc intake decreases copper absorption and is another cause of copper deficiency. One of the most common copper deficiency symptoms highlights another important mineral-mineral interaction (in addition to that of copper and zinc): A copper deficiency often results in anemia because copper-containing enzymes are required to release iron from stores and for its incorporation into its heme form. Symptoms of copper deficiency include impaired immune response and osteoporosis. Toxicity/UL:

Fluoride

Fluoride: As fluoride is not required for growth, for reproduction, or to sustain life, it is not by definition considered an essential nutrient. However, the decline in incidence of tooth decay over the past 70 years has been largely attributed to the addition of fluoride to public water supplies. It is estimated that 60% to 70% of the population is served by community water systems that receive fluoridated water. The Environmental Protection Agency (EPA) is responsible for safeguarding our public drinking water, which includes establishing ranges for fluoride that reduce rates of dental caries while not exceeding upper thresholds. Functions: Fluoride has a well-established role in the prevention of dental caries through the hardening and maintenance of tooth enamel. Fluoride is also important in stabilizing the structure of bone. Food Sources: In addition to fluoridated water, we obtain fluoride through fluoridated dental products, beverages made with fluoridated water, and to a lesser extent, marine fish. Recommendations: In addition to fluoridated water, we obtain fluoride through fluoridated dental products, beverages made with fluoridated water, and to a lesser extent, marine fish. Deficiency: Inadequate fluoride, not surprisingly, results in an increased risk of dental caries. Toxicity/UL: Fluoride may cause health issues if drinking water exceeds the standards set by the EPA. Tooth and skeletal fluorosis is characterized initially by small opaque flecks on the teeth and then by stains or pits in the teeth with longer-term exposure. The EPA warns that excessive intake over a lifetime may have adverse effects on bone, among them an increased likelihood of fractures because bones become brittle as they become excessively dense. The UL for men and women 19 years and older is set at 10 mg.

Iodine

Iodine: The iodine content of food depends on the iodine content of the environment it comes from, which varies from region to region. The highest naturally occurring concentrations of iodine are in foods from the sea, such as fish, shellfish, and plants (e.g., seaweed, algae), because the ocean contains considerable iodine. In part because the problem of goiter was so widespread, the U.S. salt company Morton began to add iodide to its salt in 1924, and the U.S. Food and Drug Administration recommended that the product be labeled with the following message: "This salt provides iodide, a necessary nutrient." Although iodine is added to most table salt in the United States, only 15% of daily salt intake comes from iodized table salt. The majority of salt intake in the United States comes from processed foods, but food manufacturers often use noniodized salt. Milk and processed grain products provide the majority of total iodine intake in the United States (about 70%). Iodine in milk originates primarily from the fortification of animal feed and the use of iodine-containing sanitizers during milk collection, while its presence in processed grain products is largely due to the use of iodine-containing food additives (dough conditioners). Functions: Iodine is an essential component of thyroid hormone, thus it is required for normal function of the thyroid gland. The pituitary gland in the brain secretes thyroid-stimulating hormone (TSH), which regulates the thyroid by increasing the uptake of iodine from the blood, stimulating thyroid hormone production and release. The thyroid hormones regulate energy metabolism and protein synthesis and play critical roles in the development of the fetal skeleton and brain, which is why iodine deficiency is especially problematic during pregnancy. Food Sources: *Cod (baked): 99 mcg *Skim Milk: 56 mcg *Fish sticks: 54 mc *Shrimp: 35 mcg *Navy Beans (cooked): 32 mcg *Egg (1 lg): 24 mcg *Cheddar Cheese = Tuna (canned in oil): 18 mcg *Beef chuck roast (baked): 14.5 mcg Recommendations: The RDA for iodine for men and women 19 years and older is 150 micrograms (the UL is 1,100 micrograms) Deficiency: In 2006, nearly half of all pregnant American women's diets were estimated to be deficient in the mineral according to World Health Organization intake recommendations. These low intakes are a major problem considering that iodine deficiency during pregnancy can lower fetal IQ to the point of causing mental retardation. When individuals do not get enough iodine, the thyroid gland cannot produce adequate levels of thyroid hormones. This can lead to goiter or hypothyroidism (underactive thyroid), which slows the metabolic rate. Goiter can occur when the thyroid gland—an endocrine gland located at the front of the neck—is not able to make enough thyroid hormone to meet the body's needs. The TSH levels rise and the thyroid gland attempts to make thyroid hormones, but it does not receive enough iodine. The thyroid gland grows and expands, trying to do its job, forming a lump in the neck that can grow as large as a grapefruit. The milder iodine deficiencies that have developed in the United States are most common among pregnant women, as the RDA for iodine during pregnancy is 50% higher than it is for nonpregnant women. Lack of iodine can adversely affect brain development and growth of the developing fetus. If a pregnant woman is extremely deficient in iodine, then cretinism can develop in her child, characterized by mental retardation, deafness and muteness, stunted growth, delayed sexual maturation, and other abnormalities. Less severe iodine deficiencies can affect neurological development in young children, resulting in below average intelligence. Adverse effects of Iodine Deficiency: *Mental Retardation, Cretinism *Increased Infant Mortality *Nodular Goiter and Hyperthyroidism *Poor Growth, Stunting *Goiter and Hypothyroidism *Lower Intelligence, Poor Educability Toxicity/UL: Excessive intake can elevate levels of TSH, disrupting thyroid function and sometimes causing some of the same symptoms as iodine deficiency: goiter, elevated TSH levels, and hypothyroidism.

Iron

Iron: Most iron in our body occurs as heme iron. Heme iron is a critical part of the protein hemoglobin. In the body, red blood cells pick up oxygen from the lungs and release it into the tissues. Red blood cells are able to pick up and transport oxygen because they contain a protein within them called hemoglobin. Hemoglobin is made up of four units, each unit contains one heme group (an iron atom surrounded by a ring-shaped structure) and one protein chain. These heme groups contain positively charged iron atoms that can bind to oxygen molecules and transport them to various areas of the body. The structure of hemoglobin allows it to be loaded with oxygen in the lungs, so it is sometimes referred to as an oxygen transport protein. In muscles, the iron-containing oxygen storage protein is myoglobin, which is similar in structure to hemoglobin but has only one heme unit and one protein chain. Myoglobin transports and stores oxygen in muscle cells and helps to coordinate the supply of oxygen to the demand of working muscles. Iron stores in the body are regulated only by controlling its absorption in the small intestine, because, unlike other minerals, iron cannot be excreted in urine or bile. In healthy individuals about 10% to 15% of dietary iron is absorbed. However, when iron stores are low, iron is absorbed more efficiently, and when its stores are high, iron is absorbed less efficiently. The body also carefully conserves iron so that daily losses are minimized. While we do lose iron through blood loss, the shedding of cells from the gastrointestinal tract and skin, and small losses in sweat, the body holds on to as much as possible. For example, when red blood cells die, iron is recycled and incorporated into new red blood cells. Iron balance in the body is achieved by carefully regulating iron absorption, storage, release, and transport. When imbalances develop, dangerous deficiencies and toxicities can occur. Functions: In addition, iron is also an integral component of many enzymes required for a host of crucial processes in the body, including energy metabolism, protection against antioxidants, the immune response, and DNA synthesis. Because of its role in DNA synthesis, iron is required for a wide variety of critically important functions, including reproduction, growth, and healing. Food Sources: Food sources offer iron in both the heme and non-heme forms. Dietary heme iron (from hemoglobin and myoglobin in animals) is present in red meats, poultry, and fish. Non-heme iron is also found in meat and fish; additionally, it is the only form of iron found in plant foods, such as lentils and beans, dried fruits, and grain products—particularly those grain products that have been fortified with iron. Although non-heme iron makes up the majority of the iron that we consume, it is not as well-absorbed by the body as heme iron. *Post Grape-Nuts iron fortified cereal: 22.07 mg *Oysters (cooked): 6.60 mg *Cashews: 3.40 mg *T-bone steak (broiled): 3.11 mg *Quinoa (cooked): 2.76 mg *Almonds (dry roasted):2.11 mg *Refried Beans: 1.99 mg *Raisins: 1.98 mg *Black Beans (cooked): 1.80 mg *Bulgar: 1.75 mg *Swiss Chard (cooked): 1.56 mg *Light Tuna: 1.30 mg *Prunes: 1.18 mg *Brown Rice: 1.03 mg *Turkey (roasted): 0.82 mg *Sweet Potato (mashed): 0.81 mg Recommendations: The RDA for iron for men 19 years and older is 8 mg; for women aged 19 to 50 years, it is 18 mg. However, these recommendations assume that 75% of iron consumption is heme iron, so for vegans and vegetarians, who primarily ingest non-heme iron, intake re-commendations are approximately doubled. Athletes who train intensively on a regular basis are estimated to have a 30% higher average iron requirement because of increased iron losses. Deficiency: Iron Deficiency Anemia (aka microcytic hypochromic anemia) The red blood cells in iron-deficiency anemia are smaller and paler than normal red blood cells. Iron deficiency anemia has many causes. The most common cause is blood loss. The combination of blood loss through menstruation and a limited or restricted diet that may minimize sources of heme iron can put premenopausal women at risk of iron-deficiency anemia. It is estimated that 15% of women aged 20 to 49 years may have iron-deficiency anemia. It can also result from insufficient dietary iron intake and is more common among vegans, who avoid foods of animal origin, and thus consume no heme iron through food consumption. The condition can also develop when the mineral cannot be properly absorbed because of disease or the presence of dietary components that inhibit non-heme iron absorption. Infants and young children need higher-than-normal amounts of iron because they are rapidly growing; iron needs are also increased during pregnancy. Iron lost through menstruation, frequent blood donations, or any other form of blood loss must be replaced. Adult men and postmenopausal women are at lower risk for iron deficiency anemia, because they lose very little iron through blood loss. People who suffer from iron deficiency anemia can have many symptoms. They can feel tired and out of breath, perform poorly at work or at school, and have slow cognitive and social development during childhood. They often have trouble maintaining their body temperature and are more susceptible to infections because their immune systems are not working properly. Iron deficiency anemia during pregnancy increases the risk of preterm birth and low birth weight, increasing the infants' risk of health problems later. Individuals thought to be suffering from this form of anemia should be evaluated and managed by a health care provider, who will try to determine the cause of the condition and may prescribe iron supplements. Toxicity/UL: The UL for iron for men and women 19 years and older is 45 mg, and higher intakes of iron can cause gastrointestinal distress. Individuals who take high doses of iron to prevent or treat iron deficiency anemia also sometimes suffer from side effects, including constipation, nausea, vomiting, and diarrhea, especially when the supplements are taken on an empty stomach. Because very little iron is excreted from the body, iron toxicity can occur when intake is too high, causing symptoms such as apathy, fatigue, liver damage, and immune problems. In children, iron poisoning is a major cause of unintentional poisoning death, causing symptoms such as nausea, vomiting, diarrhea, constipation, rapid heartbeat, dizziness, shock, and confusion (which explains why you will not find iron in "gummy" multivitamin/mineral supplements; children might mistake them for candy and consume too many with potentially fatal results). Men are at a higher risk for iron toxicity than are women because men don't experience monthly blood loss. Individuals with hereditary hemachromatosis, sometimes called iron overload disease, are also at high risk of iron toxicity because of increased absorption and high iron stores.

Manganese

Manganese: Despite being one of the most poorly absorbed of the trace minerals (generally less than 5% is absorbed), manganese deficiencies are far less common than are toxicities. Functions: It functions as a co-factor for enzymes involved in antioxidant functions, and is involved in the meta-bolism of carbohydrates, cholesterol, and amino acids. The role of manganese in amino acid metabolism makes it important for the synthesis of proteins needed for bone growth and maintenance, as well as for wound healing. Food Sources: Recommendations: Deficiency: Toxicity/UL:

Molybdenum

Molybdenum: Functions: Molybdenum is a co-factor for only four enzymes, and the function of one of these enzymes is not well-understood. Food Sources: Recommendations: Deficiency: deficiencies are unknown in healthy individuals Toxicity/UL: The average intake of the United States population is usually well-above the RDA. Risk of toxicity in humans is very low.

Selenium

Selenium: Functions: Selenium functions as a co-factor for several antioxidant enzymes and with other selenium-dependent enzymes in the activation of thyroid hormone, making it essential for normal growth, development, and metabolism. Food Sources: The highest concentrations of selenium are present in organ meats and seafood. The most common sources in the diet are meat and cereals. The selenium content of meats is fairly consistent, but the selenium content of plant foods varies widely depending on the content of the mineral in the soil where the plant was grown. Dietary selenium is generally well-absorbed, and unlike most other minerals, its absorption is not regulated in relation to nutritional status. *Light tuna (canned in water): 42.0 mcg *Salmon: 39.6 mcg *Pork tenderloin (roasted): 32.5 mcg *Post Shredded Wheat Honey Nut: 24.1 mcg *Chicken breast (roasted): 23.7 mcg *Ground beef (90%): 18.4 mcg *Hard boiled egg (1 lg): 15.4 mcg *Parmesan cheese: 9.6 mcg *Brown rice (cooked): 9.5 mcg *Whole wheat spaghetti (cooked): 8.1 mcg *Skim milk: 7.6 mcg *Cashews (dry roasted): 6.6 mcg *Asparagus (cooked): 5.5 mcg *Gold kiwi: 2.7 mcg *Grapefruit: 1.7 mcg *Green peas (cooked): 1.5 mcg Recommendations: The RDA for selenium is 55 micrograms per day for adults Deficiency: A selenium deficiency by itself seldom causes obvious symptoms or illness. However, additional stresses, such as viral infections, chemical exposure, or low intakes of other antioxidant nutrients, together with low selenium intake can cause clinical illness. For example, a selenium deficiency increases the likelihood of developing a vitamin E deficiency when intake of the vitamin are low. This occurs because selenium functions as a cofactor for an important antioxidant enzyme system and a deficiency of selenium increases oxidative stress and places a greater demand on the antioxidant function of vitamin E. Low-selenium status increases the risk of a particular form of heart disease and may increase the risk of some cancers. Inadequate selenium may also decrease immune function. Toxicity/UL: excess selenium can result in hair loss and brittle nails and in extreme cases, respiratory distress along with kidney and heart failure. The UL for selenium is 400 micrograms per day in adults. Although a single high dose of selenium may be fatal, selenium toxicity generally occurs with long-term exposure to moderately high levels of intake either through supplementation or, in rare instances, through frequent consumption of selenium-rich foods. For example, a single one-ounce serving of about six Brazil nuts contains 544 micrograms of selenium, which is about 25% above the UL. The most common toxicity symptoms are hair and nail loss, and brittleness.

Zinc

Zinc: Functions: Zinc (Zn) is required for the function of perhaps more proteins in the body than any other mineral. Research indicates that zinc binds to about 10% (~2,800) of all proteins in the body, including more than 900 enzymes. Zinc functions as a co-factor for enzymes that participate in most major metabolic pathways. The binding of zinc to proteins also plays critically important structural roles by allowing proteins to achieve and maintain their appropriate shapes. The prolific presence of zinc in so many enzyme systems and regulatory proteins means that it is required for virtually every essential process in the body, including the regulation of protein synthesis, reproduction, cell division, growth and development, immune responses, and neurological functions. Food Sources: Zinc is found in many foods but is most concentrated in meats, poultry, and certain types of seafood, such as oysters, which contain more zinc per serving than any other food. Fortified cereals, beans, and nuts also provide zinc, as do certain brands of cold lozenges and some over-the-counter drugs sold as cold remedies. *Oysters (cooked): 51.88 mg *Cheerios: 4.68 mg *T-bone steak (broiled): 4.34 mg *Cashews (dry roasted): 3.18 mg *Chicken drumstick (roasted): 2.28 mg *Almonds (dry-roasted): 1.88 mg *Swiss cheese: 1.66 mg *Plain yogurt: 1.65 mg *Turkey breast: 1.29 mg *Wild rice (cooked): 1.10 mg *Quinoa (cooked): 1.01 mg *Black beans (cooked): 0.96 mg *Green Peas: 0.95 mg *Avocado (raw, pureed): 0.78 mg *Refried beans: 0.77 mg *Mushrooms (cooked): 0.68 mg *Brown Rice: 0.60 mg *Raisins: 0.18 mg Recommendations: The recommended intake of zinc is 11 mg for men 19 years and older and 8 mg for women in the same age group. Since the body cannot store zinc, a regular daily intake is required to maintain adequate zinc status, although absorption does increase in the small intestine when intake is low. Because vegetarians absorb less zinc than nonvegetarians do, the Dietary Reference Intakes recommend that vegetarians and vegans consume twice as much zinc as nonvegetarians. Deficiency: n 1958, a young physician named Ananda Prasad evaluated a patient in Iran who suffered from severe iron deficiency and its associated symptoms. In addition, the severely stunted patient appeared to be about eight years old and had not gone through puberty, although his chronological and bone age indicated he was closer to 21 years old. This was not an isolated case; the same condition was so prevalent in Iran that it was considered an epidemic. Dr. Prasad studied the curious problem, administering iron to the patients with iron deficiency. However, Prasad found it difficult to assign all the health problems to iron deficiency, since growth retardation and the lack of secondary sex characteristics are not typically linked to iron deficiency. Seeking clues to effectively treat the patients, Prasad went to Egypt to study rural farmers with similar signs of illness, taking careful inventory of their diets. Soon, Prasad began to target the mineral zinc, which, at that time, was not thought to be of importance to human health. He knew that in the developed world, zinc is found in a variety of food sources, such fish, red meat, and dairy products. However, the diets of the individuals he studied from the developing world relied heavily on breads and grains, which contain phytates, which are substances that bind zinc and iron and prevent both minerals from being properly absorbed, accounting for both the iron deficiency and the zinc deficiency. In 1961, Dr. Prasad published an article in the American Journal of Medicine, suggesting for the first time that zinc deficiency could account for human growth retardation. By 1963, Dr. Prasad started administering zinc through clinical trials, and his participants began growing taller and developing secondary sex characteristics. Zinc supplementation has been a successful treatment for childhood diarrhea in developing nations. In addition, the prevention of zinc deficiency through zinc supplementation also reduces the risk of death from infectious disease and improves the growth and development of children. Although zinc deficiencies serious enough to produce readily identifiable symptoms are uncommon in the United States, it is estimated that about 12% of the population is at risk of deficiency. Some groups, including alcoholics, vegetarians, and the elderly, are particularly at risk of a zinc deficiency. Alcohol reduces zinc absorption and increases zinc excretion in the urine, while phytates in whole grains and legumes, which are dietary staples among vegetarians, inhibit the mineral's absorption. Zinc status in the elderly may be compromised because of reduced food intake and impaired absorption resulting from low gastric acid production. Mild to moderate zinc deficiency can cause impaired immune function, appetite loss and weight loss, delayed sexual maturation, and slowed growth. Severe zinc deficiency results in hair loss, diarrhea, infertility in men, and impaired neurological and behavioral functions. Symptoms of zinc deficiency can mimic symptoms of other nutrient deficiencies and can occur along other deficiencies in part because zinc plays an important role in the proper functioning of many other nutrients. Toxicity/UL: The UL for zinc intake for men and women 19 years and older is 40 mg. Short-term symptoms of excessive zinc intake include nausea, vomiting, abdominal cramps, and diarrhea. Chronic, longer-term effects may include copper deficiency (excessive zinc reduces the absorption of copper), altered iron function, reduced immune function, and lowered levels of high-density lipoproteins.