Health and Nutrtition - Minerals

Total Water Intake

-Includes water in beverages & foods •Water weight of fruits and vegetables typically ranges from 60 to 95%. Metabolic Water -Water formed by cells as a metabolic by-product

As the loss of body water approaches 4% of body weight, muscles lose considerable amounts of strength and endurance.

By the time body weight is reduced by 7 to 10% as a result of body fluid losses, severe weakness results. At a 20% reduction of body weight, coma and death are likely.

The sea salt that is usually sold in supermarkets is not a good source of iodine and other minerals because it has undergone processing.

Some stores sell "unrefined" or "natural" sea salt that contains much of its natural mineral content, including iodine. Consumers, however, need to avoid excess sodium from all sources, including sea salt.

The kidneys are the major regulator of the body's water content and ion concentrations. In a healthy person, the kidneys maintain proper hydration by filtering excess ions from blood as it flows through the kidney's tissues.

When the kidneys remove ions such as sodium, water follows and becomes the main component of urine. If you drink more watery fluids than your body needs, your kidneys excrete the excess water in urine.

older adults may be more susceptible to develop dehydration than younger persons, because as kidneys age, they become less able to conserve water when fluid intakes are low.

it may be necessary to remind older adults to drink more watery fluids, especially when they are physically active or in warm conditions. Nevertheless, healthy elderly persons who live independently are generally able to maintain adequate hydration

high in sodium

milk, soy sauce, chips

water shifts in and out of cells through

osmosis

Body water is lost through:

-urine, perspiration, exhaled air, feces, and insensible perspiration. Insensible perspiration: body water that passes through the skin and is not from sweat glands. Typical fluid intake = fluid lost Average is ~2.5 qt/d

Substantial blood loss is a common cause of iron deficiency anemia. Such losses of blood often result from serious intestinal diseases, severe physical injuries, and excessive menstrual bleeding. Diseases that reduce red blood cell formation or increase red blood cell destruction also cause anemia.

. It is important to note that some types of anemia are the result of genetic defects and not dietary deficiencies. Blood testing can determine which kind of anemia a person has developed, so the condition can be treated properly.

Daily water balance

.An average healthy adult consumes and produces approximately 2500 ml of water and eliminates about 2500 ml of water daily. A healthy person's average daily water input equals his or her average daily losses.

Good plant sources of calcium include broccoli and leafy greens, especially kale, collard, turnip, bok choy, and mustard greens. Nevertheless, the calcium in plant foods is generally not as bioavailable as the calcium in milk and milk products.

1 cup of fat-free milk supplies almost 300 mg of calcium, and about 30% of the calcium in milk is bioavailable.12 A cup of raw spinach supplies 30 mg of calcium, but only about 13% of that amount is bioavailable.

16 oz of water loss equals

1 lb

Each of the following foods contains about the same amount of calcium that is in 1 cup of fat-free milk (approximately 300 mg):

2 cups low-fat (2% milk) cottage cheese 2.3 oz processed cheese (American cheese) cup plain, low-fat yogurt 1.5 oz natural cheese (e.g., cheddar or Swiss) 1 cup calcium-fortified soy milk

young adult men have more lean tissue than young women

55 to 60% of an average young man's body weight is water; the average young adult woman's body has more fat and, therefore, slightly less water than an average young man's body

Physiological Roles

A few minerals, including nickel, arsenic, and silicon,and vanadiam are found in small amounts in the body, but their roles in the body are unclear. At present, this group of minerals is not classified as essential nutrients. Although there are reports of severe illness and deaths resulting from environmental exposure to high amounts of these minerals, foods generally do not contain toxic amounts of them.

Major sources of iodine include saltwater fish; seafood; seaweed; some plants, especially the leaves of plants grown near oceans; and iodized salt.

A half teaspoon of iodine-fortified salt supplies the adult RDA for iodine. Iodide fortification of salt is voluntary in the United States, so not all salt has the trace mineral added to it. Other dietary sources of iodine include food additives that contain the mineral, such as certain dough conditioners and food dyes.

The amount of urine a person produces is determined primarily by his or her total water intake.

A healthy person produces about 1 to 2 quarts (1 to 2 L) of urine per day. Healthy kidneys can form more urine, but they become less efficient at urine production when fluid intakes are less than about 2 cups (500 ml) per day.

The digestive tract, however, does not absorb 100% of the minerals in foods or dietary supplements. The body's ability to absorb and use minerals (bioavailability) depends on many factors.

A major factor is the body's need for the mineral. In general, requirements increase during periods of growth, such as infancy and puberty, and during pregnancy and breastfeeding. During these critical life stages, the bioavailability of minerals also tends to increase to help meet the body's demand.

Sodium Deficiency The typical North American's diet supplies far more sodium than the AI amount, and as a result, the average person is unlikely to become sodium deficient. A healthy body is able to regulate its sodium concentration effectively, but sodium depletion can occur in certain situations.

A person who loses more than 2 to 3% of body weight as a result of excessive sweating is at risk of sodium depletion. In most cases, drinking fluids and simply eating some salty foods or adding salt to foods is usually effective for restoring the body's sodium content. However, endurance athletes may need to consume sports drinks during competition to avoid dehydration and sodium depletion. Salt tablets are generally not recommended for sodium replacement.

Simple diffusion also occurs when there is a greater concentration of molecules on one side of a selectively permeable membrane than on the other.

A selectively permeable membrane is a barrier that allows the passage of certain substances and prevents the movement of other substances through it.

BOTTLED WATER VERSUS TAP WATER

According to data provided by the Beverage Market Corporation, each American consumed 27.6 gallons of bottled water in 2009.46 That amount of bottled water is 70% more than the amount consumed in 1999. The U.S. population drinks more bottled water than milk, juice, or any other beverage, except carbonated soft drinks. Sales revenues for bottled water were about $10.6 billion in 2009

Donating 1 pint (approximately 0.5 L) of blood represents a loss of 200 to 250 mg of iron. Even when a person consumes adequate amounts of iron, his or her body generally needs several weeks to replace the iron that was in the donated blood.

According to the American Red Cross, healthy people can give whole blood every 56 days. Young women, however, may need to donate blood less often, especially if they have heavy menstrual losses of blood.

Several factors contribute to bone loss and osteoporosis. Consuming a high-protein diet may increase urinary calcium excretion, particularly when calcium intake is low.

Additionally, family history of osteoporosis, cigarette smoking, and excessive alcohol consumption are also associated with increased risk of the disease. Other factors that contribute to low bone mass include small body frame size, irregular or absent menstrual cycles, prolonged bed rest, and use of certain medications

Zinc Toxicity: The UL for zinc is 40 mg/day. Zinc intakes that exceed the UL can reduce beneficial HDL cholesterol levels in blood. Ingesting more than 100 mg of zinc per day can also result in diarrhea, cramps, nausea, vomiting, and depressed immune system function.

Additionally, megadoses of zinc may interfere with copper absorption and metabolism. Therefore, people should avoid high intakes of zinc, unless they are under a physician's supervision. Adequacy •Adult zinc ranges from 8 to 11 mg/d •Children between 6 to 11 yrs at risk of deficiency Toxicity •Upper Limit (UL) = 40 mg/d •May reduce HDL cholesterol level •>100 mg/d results in diarrhea, cramps, vomiting, and depressed immune system

Alcohol is also a diuretic. Normally, antidiuretic hormone signals the kidneys to conserve water.

Alcohol, however, inhibits ADH secretion from the pituitary gland in the brain, enabling the kidneys to eliminate more urine than normal. Alcohol consumption actually results in urinary water losses that are greater than the volume of fluid consumed. Therefore, alcohol contributes to dehydration.

Milk products, such as fluid milk, yogurt, and cheese, provide about 75% of the calcium in American diets.11 Moreover, the calcium in milk products is well absorbed and used by the body. Not all products made from milk are rich sources of calcium. Cottage cheese, for example, does not supply as much calcium as the milk from which it is made, because the milk loses about half of its calcium content when it is processed to make cottage cheese

Although butter, sour cream, and cream cheese are made from whole milk, people generally do not eat enough of these high-fat foods to contribute much calcium to their diets.

Sources of Chromium

Although chromium is widely distributed in foods, most foods contain less than 2 mcg of the mineral per serving.44 Information regarding the chromium content of various foods is difficult to find, because most reliable food composition tables do not include this trace mineral. In general, meat, whole-grain products, yeast, fruits, and vegetables are good sources of chromium. Like selenium, the amount of chromium in plant foods reflects the chromium content of soils where crops are grown.

Young women are at risk for iron deficiency-related disorders because they often exclude meat and enriched bread and cereal products from their diets. Additionally, women of childbearing age generally lose some iron during menstruation. Women with heavy menstrual blood losses are especially prone to iron deficiency anemia.

Although pregnant women do not have to contend with menstrual blood losses, they still need to be concerned about their iron intake. The "Food & Nutrition Tips" feature on this page suggests practical ways to increase dietary sources of iron.

Salted snack foods, French fries, canned and dried soups, sauces and gravies, hot dogs and "deli" meats, cheeses, and pickled foods are high in sodium (Table 9.8). If you frequently eat these foods, your sodium intake is probably higher than recommended.

Although sodium is an essential mineral, diets that contain high amounts of sodium are associated with increased risk of hypertension. The American Medical Association has encouraged efforts to reduce the sodium content of processed foods, fast foods, and restaurant meals by at least 50% and urged the Food and Drug Administration (FDA) to develop warnings or markers on labels to indicate foods that are high in sodium

Calcium is needed for

Although the body needs calcium to form bones and teeth, the mineral is vital to all cells. Calcium is involved in muscle contraction, blood clot formation, nerve impulse transmission, and cell metabolism. Additionally, calcium may play important roles in maintaining healthy blood pressure and functioning of the immune system.

Trace Minerals

Although the body requires trace minerals in very small amounts, obtaining adequate amounts of these important nutrients can be difficult.

The body is unable to conserve potassium as well as sodium; therefore, the risk of potassium deficiency is greater than that of sodium deficiency. Individuals suffering from excessive sweating, vomiting, diarrhea, or kidney diseases that increase potassium excretion are at risk for potassium depletion. Symptoms of the condition generally include loss of appetite, muscle cramps, confusion, constipation, and increased urinary calcium excretion.

Although there is no UL for potassium, taking potassium supplements can upset the GI tract. Moreover, if a person's kidneys are not able to eliminate the excess potassium, the mineral accumulates in the blood and can cause the heart to stop beating. To avoid toxicity, do not take potassium supplements unless you are under a physician's care.

Bone Development and Maintenance

Although your bones do not appear to change shape, they are being remodeled continually in response to the physical stresses placed on them. The remodeling process involves breaking down bone where there is little stress and building bone where there is more stress. For example, if you begin to play tennis regularly and hold the racket in your right hand, osteoblasts in the bones of your right arm build bone tissue where it is needed to help support the muscular activity. As a result, the bones in that arm become denser than the bones in your left arm. Bones that are denser have greater bone mass. As a result, they are stronger and less likely to fracture than less dense bones.

Compared to plant foods, animal foods tend to be more reliable sources of minerals, and can be absorbed more easily than plant minerals - such as iron and calcium. Why?

Animal products often have higher concentrations of these minerals. Additionally, plant foods can contain substances that reduce the bioavailability of minerals, particularly calcium, zinc, and iron. On the other hand, plants supply more magnesium and manganese than animal foods.

The Environmental Protection Agency (EPA) regulates the sanitation of public water supplies in the United States.

Another federal agency, the Food and Drug Administration (FDA), regulates bottled water products that are marketed for interstate commerce. Neither agency "certifies" bottled water

When you are hot and perspiring heavily, your kidneys try to conserve as much water as possible to avoid dehydration.

Antidiuretic hormone (ADH) and aldosterone (al-dahs'-te-rown) are two hormones that participate in the body's efforts to maintain fluid balance. In response to dehydration, the posterior pituitary gland in the brain releases antidiuretic hormone. Antidiuretic hormone stimulates the kidneys to conserve water. Additionally, the adrenal glands secrete aldosterone.

The FDA uses place of origin to classify some bottled waters.

Artesian well water," for example, must come from a well that taps an aquifer, a body of water found between porous layers of rock, sand, and earth.

Kidney stones often contain the mineral calcium

As a kidney stone moves out of the kidney and enters the tube leading to the bladder, it may cause considerable pain and bloody urine until it passes out of the body. Dehydration increases the likelihood of forming kidney stones.

A massive earthquake struck the island nation of Haiti on January 12, 2010, devastating a region that included the island's highly populated major city, Port-au-Prince.

As a result of the earthquake, many Haitians had no access to drinkable water. People can survive for a few days in such conditions before dehydration contributes to their deaths.

Why Is Sodium Necessary?

As mentioned in the "Water" section of this chapter, sodium plays a major role in maintaining normal fluid balance. The mineral is also necessary for the transmission of impulses by nerves, for transporting small substances such as glucose and amino acids into cells, and for functioning of muscles.

simple diffusion occurs when a sugar cube is dropped into a cup of hot tea.

As the cube dissolves, the concentration of sugar molecules around the cube becomes higher than the concentration of sugar molecules near the surface of the tea. However, the sugar molecules spontaneously diffuse throughout the tea, and eventually, the concentration of sugar molecules and water molecules becomes evenly distributed within the beverage.

People who are sick, especially children with fever, vomiting, diarrhea, and increased perspiration, may need to be given special solutions of water and electrolytes to prevent dehydration.

Athletes and other people who work or exercise outdoors, especially in hot conditions, also need to stay properly hydrated to avoid dehydration and heat-related illnesses such as heat exhaustion

Results of recent studies involving laboratory animals suggested that low doses of BPA were harmful. More research is needed to determine the extent to which BPA can affect human health, especially infants and children who are exposed to the chemical. Nevertheless, concern over the safety of BPA has encouraged some plastic bottle manufacturers to discontinue using the chemical in their products

Avoid heating foods in polycarbonate plastic containers. Avoid plastic containers that have the symbol shown in Figure 9.24. Do not wash polycarbonate containers in the dishwasher or with harsh detergents. Reduce your intake of canned foods. Cook or store foods and beverages in glass, porcelain, or stainless steel containers. Avoid using polycarbonate dishware, cups, or eating utensils for serving foods (especially hot foods or liquids). Avoid baby bottles and toys that contain BPA.

Minerals are indestructable

Because minerals cannot be destroyed, heating a food or exposing it to most other environmental conditions will not affect the food's mineral content. However, minerals are water soluble, and they can leach out of a food and into cooking water. By using the cooking water to make soups or sauces, you can obtain minerals from the food that would otherwise be discarded.

Safety standards for bottled water are similar to those established by the EPA for tap water. According to FDA guidelines, bottled water manufacturers are responsible for producing safe products. Production procedures for bottled water must follow manufacturing regulations established and enforced by the FDA. Additionally, the FDA inspects water bottling facilities regularly.

Because of FDA regulations and oversight, consumers can be assured that their supply of bottled water is safe. Additionally, most Americans can trust the safety of their tap water because the vast majority of municipal water systems in the United States are regulated by the Safe Drinking Water Act (SDWA). As a result of this law, most tap water undergoes a thorough purification process and is constantly tested for safety. If such testing indicates the water supply may pose a threat to public health, consumers are warned through media, and a "boil order"—requirement to boil water for 10 minutes to kill harmful microorganisms—may be issued.

Aldosterone signals kidneys to reduce the elimination of sodium in urine and, as a result, the kidneys return the mineral to the general circulation.

Because water follows sodium, it is conserved as well.

Dietary Sources of Iron

Beef, fish, and poultry ("meat") contain more iron than most plant foods. Some of the iron in meat is present as hemoglobin and myoglobin. These forms of iron are collectively referred to as heme iron. The remaining iron in meat, as well as all the iron in vegetables, grains, and supplements, is nonheme iron.

What Causes Hypertension? Most cases of hypertension do not have simple causes, but advanced age, African-American ancestry, obesity, physical inactivity, smoking cigarettes, and excess alcohol and sodium intakes are among the major risk factors for the condition

Blood pressure usually increases as a person ages, probably in part because plaque builds up in arteries (atherosclerosis) and interferes with the normal functioning of the blood vessels. Healthy arteries are flexible tubes that expand with each heartbeat and recoil in between beats. Atherosclerotic arteries are less flexible and cannot expand as much as healthy arteries. As a result, the heart must work harder to pump blood through the stiff arteries and blood pressure becomes chronically elevated.

Bok Choy (Pak Choi or Chinese Cabbage)

Bok choy is a cruciferous vegetable that is typically used in Asian cookery. Cruciferous vegetables contain phytochemicals that may have cancer-fighting activity. The leaves and stalks are steamed or sautéed with other vegetables. Bok choy is a good source of minerals, especially iron, calcium, and potassium; the vegetable also contains high amounts of vitamin C.

After red blood cells die, the body breaks them down and conserves most of the iron that was in hemoglobin.

By doing so, the body can recycle the trace mineral to make hemoglobin for new red blood cells. Nonetheless, some iron is lost each day via the GI tract, urine, and skin. Any form of bleeding, including menstruation, also contributes to iron losses. Replacing the iron is essential to good health.

What Is a Diuretic?

Caffeine is a diuretic, a substance that increases urine production. Coffee, tea, energy drinks, and soft drinks often contain caffeine or caffeine-related compounds. However, the water consumed in caffeinated beverages is not completely lost in urine, so drinking these fluids may still contribute to meeting your water needs

When the level of calcium in blood is too high, the thyroid gland secretes the hormone calcitonin (cal'-sih-toe-nin).

Calcitonin signals another type of bone cell (osteoblasts) to remove excess calcium from blood and build bone tissue. All these physiological responses help maintain your blood calcium level within the normal range.

Calcium (Ca)

Calcium is the most plentiful mineral element in the human body. All cells need calcium, but more than 99% of the body's calcium is in an inorganic compound that forms the structural component of bones and teeth. The remaining calcium is in muscle tissue and extracellular fluid.

, the more processing a plant food undergoes, the lower its natural mineral content.

Cereal grains, for example, naturally contain selenium, zinc, copper, and some other minerals, but these micronutrients are lost during refinement. Iron is the only mineral added to grains during enrichment. To obtain a variety of minerals, include some whole-grain products in your diet each day.

Older people, especially aging women, do not absorb calcium as well as younger people. Thus, recommendations for calcium intakes are higher for people over 50 years of age than for younger adults. In addition to advanced age, other factors that reduce calcium absorption include vitamin D deficiency and diarrhea.

Certain brands of antacids contain calcium carbonate. These products can be an inexpensive way of obtaining some calcium. An antacid pill that contains 750 mg of calcium carbonate provides 300 mg ofelemental calcium. However, using calcium carbonate containing antacids as a source of calcium can increase the likelihood of calcium toxicity. Therefore, consumers should avoid taking too many antacids or other calcium supplements. The UL for calcium is 2000 to 2500 mg/day.

Cheese

Cheese is a good source of calcium, phosphorus, and sodium.

Why do so many Americans drink bottled water when tap water is much less costly? Among adults, taste, convenience, and health concerns were major reasons they chose bottled water over other beverages. For most Americans, however, bottled water is usually unnecessary and expensive, as it is often very similar to tap water.

Consumers need to be aware that the water in some bottled water products actually comes from a municipal water supply. However, when public water supplies are disrupted by hurricanes, tornadoes, or earthquakes, drinking bottled water may be a consumer's only option. What is bottled water? Is it safe to drink?

Because of their rapid growth rates, infants and toddlers have higher needs for iron than older children. Furthermore, iron appears to be necessary for normal nervous system functioning, including brain development. Iron-deficient infants can experience delays in the development of normal motor and mental functions

Consuming too much milk may play a role in the development of iron deficiency in children. Milk is a poor source of iron. Thus, children who drink excessive amounts of milk may not have the appetite to eat foods that are more reliable iron sources. The calcium that is in milk also interferes with iron absorption when the beverage is consumed with foods that contain the mineral. To reduce the risk of iron deficiency, children should be encouraged to eat more iron-rich foods, such as meat, products made from soybeans, and iron-fortified cereals.

Iodine deficiency is a serious threat to health in places where soils are iodine deficient and commonly eaten foods are not fortified with the trace mineral, such as regions of Latin America, India, Southeast Asia, and Africa.

Currently, international health organizations are engaging in efforts to eliminate iodine deficiency, primarily by promoting the use of iodized salt or iodide-fortified vegetable oils.

Meat is the major source of iron in the typical American diet. Other important sources of iron are fortified cereals and products made from enriched flour, such as breads and rolls

Dairy products are poor sources of iron. Whole grains are good sources of several trace minerals.

Scientists do not know what causes a "hangover," the headache and overall discomfort that occurs a few hours after drinking too much alcohol.

Dehydration, the body's immune response, and congeners may be responsible for the unpleasant, delayed side effects of excess alcohol consumption.6 Congeners are substances in alcoholic drinks that contribute to the taste and color of the beverages. (Beer and vodka have lower congener contents than red wine and whiskey.) Alcoholic drinks with high congener contents tend to produce more severe hangovers than drinks with lower contents of these substances.

Dehydration

Despite the body's mechanisms to balance its water content, some fluid is constantly being lost, primarily via the skin and lungs. If a person does not consume enough fluids to replace that water, dehydration can occur.

Iodine (Iodide)

During World War I, physicians noted that men drafted into the U.S. military from the Great Lakes region were far more likely to have goiter (goy'-ter) than men from some other areas of the country. Goiter is enlargement of the thyroid gland that is not the result of cancer

In addition to the water in beverages and foods, a considerable amount of water enters the digestive tract daily through secretions from the mouth, stomach, intestine, pancreas, and gallbladder. The intestinal tract absorbs most of this water too.

Each day, only about 0.4 to 0.8 cup (100 to 200 ml) of the water that enters the digestive tract is not absorbed. The body eventually eliminates the unabsorbed water in feces.

The following suggestions can add more iron to your diet:

Eat lean meat, poultry, or fish with plant sources of iron. Combine soybeans with tomatoes or tomato sauce. Add orange segments or chopped tomatoes to spinach salads or cooked spinach. Add chopped onions and green peppers to peas or beans. Serve sweet potatoes with fresh orange segments or dried apricots. Add raspberries, strawberries, raisins, or dried apricots to cereal. Drink orange juice when eating peanut butter or soy nut butter sandwiches. Consume watermelon, dried plums, dried apricots, or raisins for snacks.

Why are minerals important?

Essential minerals have diverse roles in the body.Minerals may also function as inorganic ions, substances that have negative or positive charges Some minerals form inorganic structural components of tissues, such as calcium and phosphorus in bones and teeth. -Ions -Blood clotting -Fluid balance -Acid-base balance -Cofactors in chemical reactions -Part of certain enzymes and hormones

Joint pain is the most common complaint of people suffering from HH. Other common signs and symptoms of the disorder include fatigue, lack of energy, abdominal pain, loss of sex drive, and heart problems.

Even though people with HH begin accumulating iron early in life, they often do not report any signs and symptoms of the disease until they are over 30 years of age. Testing is available to determine the presence of the genes that are responsible for the disease.

Prasad noted that the young man ate unleavened ("flat") bread almost exclusively. After examining other patients in Iran and Egypt with similar health problems and dietary practices, Prasad hypothesized that diet was responsible for the condition.

Eventually, medical researchers determined that Prasad's patients had severe zinc deficiencies. After these patients were given zinc supplements, they began to grow and develop normally. Prasad later determined that girls also experienced stunted growth and delays in sexual maturation as a result of zinc deficiency

Rapid weight loss is a sign of dehydration.

Every 16 ounces (about 0.5 L) of water that the body loses represents a pound of body weight. If you lose 1 to 2% of your usual body weight in fluids, you will feel fatigued and thirsty. If you weigh 150 pounds, for example, and your weight drops 3 pounds after exercising in hot conditions, you have lost 2% of your body weight, primarily as water weight.

Reducing the Risk of Osteoporosis Efforts to reduce the risk of osteoporosis should begin early in life. Proper diet and regular exercise are especially important from early childhood through late adolescence, because the body actively builds bone during these life stages.

Exposing skin to sunlight can stimulate the body's ability to form vitamin D, but some people will need to take calcium and vitamin D supplements.

To estimate the mineral contents of packaged foods, you can check the panels on food labels.

Food manufacturers are required to indicate amounts of iron and calcium in a serving of food as percentages of these micronutrients' Daily Values (%DVs). Daily Values have been established for several mineral nutrients

Iodine (I2) is poisonous, but most ingested iodine loses an electron to become the iodide ion (I−) in the digestive tract.30 Iodide is the form of iodine that the body uses. Most of the iodide in an adult's body is located in the thyroid gland. Under normal conditions, the kidneys filter and eliminate excess iodide from blood.

From 1917 to 1922, researchers in Ohio conducted an experiment on a group of girls in which one group of the children received doses of iodine, whereas the other group (the control group) did not receive the trace mineral. The results of the study indicated iodine was nearly 100% effective in preventing goiter in the healthy children. Moreover, the majority of the girls who already had goiters when they received the iodine experienced a reduction in the size of their thyroid glands by the end of the study. In 1924, iodide was added to table salt in the United States, and as a result, cases of goiter caused by iodine deficiency rarely occur in this country. Today, use of iodized salt is the major method of preventing iodine deficiencies in developed nations, but inadequate iodine intake and goiters are still common in central Asia and central Africa.

Which of the following statements is false? Lean tissue contains more water than fat tissue. Water is a major solvent. Generally, young women have more body water than young men. Water does not provide energy.

Generally, young women have more body water than young men.

Hemoglobin is the iron-containing protein in red blood cells that transports oxygen to tissues and some carbon dioxide away from tissues.

Hemoglobin is also responsible for the red color of oxygenated blood

Iron Overload: Hereditary Hemochromatosis Iron overload is a condition characterized by excess iron in the body. Iron overload occurs when toxic amounts of iron supplements are ingested, but the condition also results from certain genetic diseases

Hereditary hemochromatosis (he′-mo-crow′-ma-toe-sis) is the most common type of iron overload disease in the United States. People who have hereditary hemochromatosis (HH) absorb too much iron. The body has no way to eliminate the excess iron, so the mineral accumulates in tissues and can cause joint pain, abnormal bronze skin color, and damage to the liver, heart, adrenal glands, and pancreas.

Sources of water

How much water is necessary to drink for good health? Contrary to popular belief, there is no "rule of thumb" recommendation that specifies how many glasses of water to consume each day.3 Factors such as environmental temperatures, health conditions, physical activities, and dietary choices influence individual water requirements. Thus, total water intakes vary widely. Total water intake refers to water ingested by consuming beverages and foods.

Regulating Iron: Under normal conditions, the body regulates iron absorption and conservation. The digestive tract absorbs only 5 to 15% of the iron in foods.

However, the intestinal tract can absorb more iron when the body's need for the trace mineral increases. Despite iron enrichment and fortification, only about 5% of the iron added to grain products is absorbed. The liver, the body's main site for iron storage, incorporates the trace mineral into the protein ferritin (fer′-ih-tin) until it is needed. Iron from broken down hemoglobin is "recycled" and incorporated into new hemoglobin

Other factors that influence the bioavailability of zinc include the body's need for the mineral and the presence of large amounts of certain other metals. During times when a healthy body needs zinc, the small intestine absorbs more.

However, the presence of excess copper or iron in the small intestine interferes with zinc absorption. Thus, iron supplements should be taken between meals instead of with them

Calcium Toxicity The Upper Level (UL) for calcium is 2000 to 2500 mg/day. Normally, the small intestine prevents too much calcium from being absorbed. However, taking too many calcium-containing antacids or supplements, or drinking too much vitamin D-fortified milk can result in excessive calcium absorption and hypercalcemia

Hypercalcemia (hyper = excess; calcemia = calcium in the blood) is a condition characterized by a higher-than-normal concentration of calcium in blood. Signs and symptoms of hypercalcemia include kidney stones, bone pain, muscle weakness, fatigue, and hypertension.Treatment for hypercalcemia may include avoiding vitamin D and calcium supplements to reduce calcium absorption.

Sodium and Hypertension

Hypertension, a condition characterized by persistently elevated blood pressure, is a serious public health problem in the United States. Compared to people with normal blood pressure, hypertensive individuals have greater risk of cardiovascular disease (CVD), especially heart disease and stroke, as well as kidney failure and damage to other organs. Approximately 30% of adult Americans have hypertension. Children can also develop hypertension. A study of ethnically diverse 14-year-old children in Texas, California, and North Carolina indicated that nearly one-fourth of the adolescents had hypertension. Hypertension is often called the "silent killer," because high blood pressure generally does not cause symptoms until the affected person's organs and blood vessels have been damaged.

Thyroid hormone controls the rate of cell metabolism, that is, the rate at which cells obtain energy. The thyroid gland traps iodide from the bloodstream and accumulates the element for thyroid hormone synthesis.

If a person's iodine intake is too low, the thyroid gland enlarges as it attempts to remove as much iodide as possible from the bloodstream. It is important to note that an enlarged thyroid gland can also be a sign of some diseases and conditions that are not related to iodine intake.

Anemia occurs when oxygen transport in blood is impaired, generally because there are not enough red blood cells to carry the oxygen or the red blood cells do not contain enough hemoglobin

If oxygen is lacking, cells cannot release considerable amounts of energy from macronutrients, so symptoms of iron deficiency anemia include lack of energy and difficulty concentrating on mental activities. Furthermore, the heart of a person suffering from anemia has to work harder to circulate oxygen-poor blood throughout the body. Over time, anemia can cause rapid or irregular heartbeat, chest pain, an enlarged heart, and even heart failure

Goiters often occur among populations living in areas that have iodine-depleted soil. In general, these regions are inland and far from an ocean

If people in these communities limit their diets to locally produced foods, they might not have enough iodine in their diets.

Cells also contain iron in cytochromes (sigh′-toe-crowms), a group of proteins that are necessary for certain chemical reactions involved in the release of energy from macronutrients.

If the body does not have enough iron to make hemoglobin, myoglobin, and the cytochromes, cells cannot obtain the energy they need to perform work. Thus, fatigue is a major symptom of iron deficiency. Iron also plays roles in immune system function and brain development.

Kidneys also remove drugs and metabolic waste products, such as urea, from the bloodstream. Sometimes, minerals and waste products settle out of urine and collect into crystals.

If the crystals enlarge and form a hard mass, the object is called a kidney stone

The simplest way to determine if you are consuming enough water is to observe the volume of your urine. When your fluid intake is adequate, your kidneys will produce enough urine to maintain fluid balance.

If you consume more fluid than needed, your kidneys will eliminate the excess, and you will produce plenty of urine. On the other hand, if you limit your fluid intake or have high fluid losses such as in sweat, you will produce small amounts of urine.

Dietary Guidelines for Americans 2010 recommends less than 2300 mg of sodium daily.26 That amount of sodium is in 6 g (about 1 teaspoon) of table salt. Members of high-risk populations, African-Americans, for example, should limit their sodium intake to no more than 1500 mg per day. People who are being treated for hypertension should check with their physician for advice concerning an acceptable sodium intake.

If you want to lower your sodium intake, try gradually reducing your use of salt and consumption of salty foods. By doing so, you will eventually become accustomed to the taste of less salty food. To replace salt as a seasoning, try using garlic, citrus juice, and herbs and spices to enhance the taste of foods. Furthermore, avoid buying seasonings with added salt, such as "garlic salt" or "onion salt," and check the ingredient list to purchase seasonings without added salt (garlic powder or onion powder) instead.

Zinc (Zn)

In 1958, physician Ananda Prasad was working in Iran when he examined a 21-year-old man with dwarfism, intellectual disability, iron deficiency anemia, and underdeveloped sexual organs

Fluoride is often added to public water supplies. Although fluoride is not essential for life, the mineral strengthens bones and teeth when consumed in adequate amounts.

In 2008, over 195 million people, or about 72% of the United States population served by public water supplies, drank water that contained optimal fluoride levels

Iron Deficiency-Related Disorders: Low blood iron levels usually result from losing blood, consuming diets that lack iron, or being unable to absorb dietary iron.

In cases of iron deficiency, the body's iron stores are low but not low enough to result in severe health problems. Nevertheless, iron deficiency can still have widespread negative effects on the body, including interfering with normal growth, behavior, immune system function, cardiac function, and energy metabolism. Furthermore, iron deficiency can lead to iron deficiency anemia.

Breastfed babies can be at risk of zinc deficiency. Although breast milk contains zinc, the milk does not supply enough of the trace mineral for infants who are older than 6 months of age. To increase the likelihood that their diets contain enough zinc, breastfed babies who are between 6 and 12 months of age need to consume foods that contain the trace mineral, such as zinc-fortified infant cereal.

In children and adolescents, zinc deficiency can cause growth retardation and delayed sexual maturation. Adult men who are zinc deficient may experience sexual dysfunction, particularly the inability to attain an erection. Other signs of zinc deficiency include loss of appetite, diarrhea, hair loss, dermatitis, poor wound healing, impaired sense of taste, and mental slowness

Sources of Selenium

In most countries, plant foods are the major dietary sources of selenium. Although the selenium content of foods varies, nuts, whole-grain products, seafood, and meats are generally rich sources of the trace mineral Because Brazil nuts can have very high selenium contents, people should not eat these nuts regularly.

In the regions where the men who were zinc deficient lived, the typical diet was comprised primarily of unleavened whole-wheat bread and little animal protein. Unleavened whole-wheat bread is naturally high in phytic acid and fiber, substances that decrease zinc bioavailability.

In places where people use yeast to leaven (raise) bread dough, severe zinc deficiency is less likely to occur. Yeast reduces the binding effects of phytic acid and fiber, making zinc more bioavailable. Consuming zinc-rich sources of animal protein, such as meat and milk, also reduces the likelihood of zinc deficiency.

In 2009, the FDA warned the public about using two intranasal ("within the nose") forms of Zicam, a nonprescription, zinc-containing product. The agency had received several reports that the alternative medical treatment for the common cold may result in loss of sense of smell

In response to FDA actions, the manufacturer of Zicam voluntarily recalled the products, removing them from the marketplace. Results of studies do not provide consistent evidence that zinc helps reduce the severity or duration of colds, but more research is needed to clarify whether cold products that contain zinc may be beneficial.

Effects of antidiuretic hormone and adolsterone on kidneys.

In response to dehydration, the posterior pituitary gland in the brain secretes antidiuretic hormone (ADH), which signals the kidneys to conserve water. Additionally, the adrenal glands secrete the hormone aldosterone. Aldosterone reduces urinary excretion of sodium. When the kidneys retain sodium, they return the mineral to the general circulation. Because water follows sodium, it is conserved as well.

To understand some of water's functions in the body, it is necessary to understand how water-soluble substances can become distributed when they are in water.

In some instances, the molecules move by simple diffusion; that is, the molecules move from where they are highly concentrated to where they are less concentrated

There are many different kinds of anemia, but iron deficiency anemia is the most common form. According to the World Health Organization (WHO), over 30% of the world's population suffers from anemia, and many cases of the condition are due to iron deficiency

In the United States, iron deficiency is the most common nutritional deficiency and the leading cause of anemia

Which of the following statements is false? Iodine is necessary for normal thyroid function. In the United States, milk is usually fortified with iodide. Having too much or too little iodine in the diet can cause the thyroid gland to enlarge. Saltwater fish and other seafood are sources of iodine.

In the United States, milk is usually fortified with iodide.

Why Is Selenium Necessary?

In the body, selenium functions as a component of several proteins referred to as selenoproteins (sell'-in-oh-pro'-teens). Many selenoproteins are antioxidants. Other selenoproteins are necessary for the normal functioning of the immune system and thyroid gland. Results of some epidemiological studies suggest that high intakes of selenium reduce the risk of certain cancers. However, findings from other studies do not indicate selenium lowers the risk of cancer. More research is needed to determine whether selenium supplementation is useful for cancer prevention. selenium is Part of several proteins called selenoproteins •Many selenoproteins are antioxidants. •May reduce risk of certain cancers

By 20 years of age, healthy young men and women have acquired 85 to 90% of their adult bone mass.16 Regardless of one's sex, loss of bone tissue begins in mid-adulthood. In men, bone loss is slow and steady beginning around age 30.

In women, however, the rate of bone loss increases significantly after menopause, that is, after menstrual cycles have ceased. At this time of life, women have the highest risk of osteoporosis. Why? The hormone estrogen is needed for normal bone development and maintenance. In women of childbearing age, ovaries are the primary source of estrogen. After menopause, a woman's ovaries no longer produce estrogen, and as a result, her rate of bone loss exceeds the rate of bone replacement. Because estrogen is so important to maintaining strong bones, young adult women should see a physician if they have signs of estrogen deficiency, such as irregular menstrual cycles.

Perspiration is body water that is secreted by sweat glands in skin. When perspiration reaches the skin's surface, it evaporates into the air. This process helps cool the body and maintain its normal temperature.

Insensible perspiration is body water that diffuses through the layers of skin or is exhaled from the lungs instead of being secreted by sweat glands.3 People are usually unaware that their bodies are constantly losing water in this manner—hence, the term "insensible" perspiration.

Body Water Distribution

Intracellular Water Water inside the cells ~ 2/3 of body water is intracellular Extracellular Water Water surrounding the cells or in the fluid portion of blood (plasma) Balance between intra- and extracellular fluid is maintained by concentration of ions, particularly sodium, potassium, chloride, and phosphate ions

Fluid compartments in the body

Intracellular water is inside cells; extracellular water surrounds cells (tissue fluid) or is the fluid in blood (plasma). Water is exchanged between plasma and tissue fluid (large arrows) as well as between tissue and intracellular fluids (small arrows).

The adult RDA for iodine is 150 mcg/day. Most Americans have adequate iodine intakes. As many Americans, particularly older adults, try to reduce their risk of hypertension by using less salt, iodine intakes may decline to marginal or inadequate levels. Iodine Toxicity •UL = 1.1 mg/d •May result in enlargement of thyroid gland

Iodine Deficiency: In cases of iodine deficiency, the thyroid gland produces insufficient amounts of thyroid hormone and goiter develops. As a result of the lack of thyroid hormone, iodine-deficient people generally have low metabolic rates and elevated blood cholesterol levels. Other signs and symptoms of iodine deficiency include fatigue, difficulty concentrating on mental tasks, weight gain, intolerance of cold temperatures, constipation, and dry skin.

The body maintains the balance of compartmental fluids and proper hydration, adequate water status, primarily by controlling concentrations of ions in each compartment.

Ions are elements or small molecules that have electrical charges (electrolytes). Water is attracted to ions, such as sodium, potassium, phosphate, and chloride ions. Overall, where ions go, water follows.

Iron, for example, is one of Earth's most plentiful metals, but the total amount of iron in the human body is quite small, averaging only about 0.006% of a person's body weight

Iron (Fe): Associating iron with strength makes sense, because muscular strength and endurance are reduced when the body lacks iron. Iron is a component of hemoglobin and myoglobin (my′-o-glow-bin).

Treatment for iron deficiency anemia generally includes iron supplements and the addition of iron-rich foods to the diet.

It is also important to find and treat factors that may be causing the deficiency, such as intestinal bleeding.

kidneys

Kidneys: -Are the major regulator of body's water content & ion concentration. -Maintain proper hydration by filtering excess ions from the blood. •Remove excess sodium ions; water follows sodium. -Remove drugs & metabolic wastes. •Urea & uric acid — waste products of protein metabolism.

50 to 75% of his or her body is water weight

Lean muscle tissue contains more water (about 73%) than fat tissue (about 20%).

Potassium (K) Potassium is the primary positively charged ion in the intracellular fluid. In fact, most of the body's potassium is in cells. All cells need potassium, but nerve and muscle cells contain high amounts of the mineral.

Like sodium, potassium plays a key role in maintaining proper fluid balance. Unlike sodium, potassium is associated with lower, rather than higher, blood pressure values. Potassium is also necessary for transmitting nerve impulses, contracting muscles, and maintaining normal kidney function. Potassium-rich diets, such as the DASH diet, may lower blood pressure, reduce the risk of developing kidney stones, and possibly decrease bone loss. A natural way to counteract high sodium intakes is to consume foods naturally rich in potassium and low in sodium, such as fruits.

Adult RDAs for magnesium range from 310 to 420 mg/day. Many people in the United States do not consume recommended amounts of magnesium.14 Among adult men and women, white Americans tend to consume significantly more magnesium than African-Americans.29 Nevertheless, magnesium intake is lower among older adults in every racial and ethnic group.

Magnesium Deficiency Although many Americans consume less than recommended amounts of magnesium, cases of magnesium deficiency rarely occur among healthy members of the population. Nevertheless, alcoholics, people with poorly controlled diabetes, or persons who use certain medications (diuretics) that increase urinary excretion of magnesium have high risk of magnesium deficiency. Older adults are also at risk of magnesium deficiency because their bodies absorb less of the mineral and urinary losses increase with advancing age. Most likely in girls between 14-18 yrs of age

In humans, mild magnesium deficiency can cause irritability, weakness, loss of appetite, and muscle twitching. Signs and symptoms of severe magnesium deficiency often include rapid heartbeat, inability to relax muscles, disorientation, and hallucinations. Chronic magnesium deficiency may increase the risk of osteoporosis, because the deficiency lowers the level of calcium in blood.

Magnesium Toxicity Magnesium toxicity rarely occurs from eating too much magnesium-rich food.29 Toxicity is more likely to occur from ingesting excessive magnesium from laxatives, antacids, or dietary supplements that contain the mineral. Thus, the UL for the micronutrient (350 mg/day) is for magnesium-containing medications and not food sources. A person who consumes too much magnesium often develops diarrhea. Patients suffering from kidney failure and elderly persons have high risk of magnesium toxicity, because their kidneys do not excrete the mineral as effectively as the kidneys of younger, healthier individuals. In cases of kidney failure, the high concentration of magnesium in blood causes weakness, nausea, slowed breathing, coma, and death.

Sources of Magnesium

Magnesium is in chlorophyll, the green pigment in plants. Therefore, it is not surprising that plant foods, such as spinach, green leafy vegetables, whole grains, beans, nuts, seeds, and chocolate, are the richest sources of magnesium. Animal products, such as milk and meats, also supply some magnesium. T. Refined grains are generally low in magnesium, because the magnesium-rich bran and germ are removed during processing.

Magnesium (Mg)

Magnesium participates in more than 300 chemical reactions in the body.29 The essential mineral also helps regulate normal muscle and nerve function as well as blood pressure and blood glucose levels. Additionally, the body needs magnesium to maintain strong bones and a healthy immune system. Magnesium may help prevent diabetes, hypertension, and CVD. However, more research is needed to clarify the mineral's role in these diseases. Normally, humans absorb about 40 to 60% of the magnesium in their diets, but as much as 80% of the magnesium in food may be absorbed when the body lacks the mineral. The kidneys regulate blood concentrations of magnesium and can reduce urinary losses of the mineral when the body's level of magnesium is low.

Adult RDAs for zinc range from 8 mg to 11 mg/day. In the United States, the average adult consumes adequate amounts of zinc. Thus, zinc deficiency is not a widespread problem in the United States. However, alcoholics have high risk of zinc deficiency, because alcohol reduces zinc absorption and increases excretion of the mineral in urine.

Making matters worse, many people who suffer from alcoholism do not consume nutritious diets. People with chronic diarrhea or digestive tract diseases can also develop zinc deficiency. Furthermore, vegetarians need more zinc than people who eat meat, because the GI tract does not absorb zinc from plant foods as well as from animal foods

Calcium Supplements

Many adults find it difficult to consume enough milk products and other calcium-rich foods to achieve adequate intakes of the mineral. Thus, taking calcium supplements or antacids that contain calcium has become a common practice, especially among older adults. Dietary supplements containing calcium carbonate are the most commonly used type of calcium supplement. Supplements made with calcium citrate are also available.

A cofactor is an ion or molecule that catalyzes chemical reactions.

Many minerals are components of various enzymes, hormones, or other organic molecules, such as cobalt in vitamin B-12, iron in hemoglobin, and sulfur in the amino acids methionine and cysteine. Although cells cannot metabolize minerals for energy, certain minerals are involved in chemical reactions that release energy from macronutrients.

Mineral intake

Many minerals have a narrow range of safe intake. As a result, it is relatively easy to consume a toxic amount, especially by taking supplements that only contain a particular mineral

Dietary supplements are another source of minerals. A daily multiple vitamin and mineral supplement is generally safe for healthy people, because a dose of this type of supplement does not provide high amounts of minerals. However, people need to be careful when taking dietary supplements that contain individual minerals, such as iron or selenium.

Many minerals have a narrow range of safe intake; therefore, it is easy to consume a toxic amount, especially by taking supplements that contain only a particular mineral.Additionally, an excess of one mineral can interfere with the absorption or metabolism of other minerals. For example, the presence of a large amount of zinc in the intestinal tract decreases copper absorption. Single-mineral supplements are usually unnecessary unless they are prescribed to treat a specific medical condition, such as iron deficiency.

HH most often affects people who have northern European ancestors. In the United States, about 5 in every 1000 non-Hispanic white Americans are susceptible to developing the disease

Men are more likely to be diagnosed with HH than women. Additionally, men tend to develop health problems from the excess iron at a younger age than women with the condition.

Cells also form some water as a by-product of metabolism. Physically inactive people typically form about 1 to 1.5 cups (250 to 350 ml) of water per day; very active people can produce about 2 to 2.5 cups (500 ml to 600 ml) of water daily.

Metabolic water also contributes to the body's fluid balance.

Fractures, especially hip fractures, can be devastating events for the elderly. Only about 15% of older people who break their hip can walk without assistance six months after the fracture occurred

Moreover, about 25% of older Americans who experience a broken hip die within one year of the injury.

Other sources of magnesium are "hard" tap water and dietary supplements. However, amounts of magnesium in tap water can vary considerably.

Moreover, the body does not absorb the form of magnesium (magnesium oxide) in multivitamin/mineral supplements very well. Nevertheless, hard water and magnesium supplements can still contribute to meeting a person's magnesium needs. Roles the body include: -Regulation of muscle and nerve function -Maintenance of strong bones -Strengthening the immune system

Why Is Chromium Necessary?

Most cells require the hormone insulin to obtain glucose from the bloodstream. Chromium may enhance insulin's action on cell membranes and, in a way, help to "hold the door open" for glucose's entry into the cells. Can people who have diabetes experience better blood glucose regulation by taking chromium supplements? A review of scientific research indicated mixed results when people took chromium supplements to improve their blood glucose levels. In some of the studies, chromium supplements were helpful for people with diabetes, but the results of other studies indicated no such benefits.

Sources of Sodium

Most uncooked vegetables, raw meats, and grain products are naturally low in sodium. Thus, most of the sodium Americans consume is from the salt that is added to food during processing, during preparation, or at the table. As a food additive, salt enhances flavors and can prevent the growth of microorganisms responsible for food spoilage. Other food additives that contain sodium include sodium nitrate, sodium citrate, and monosodium glutamate (MSG), a seasoning that is often added to foods served in Chinese restaurants.

The UL for iodine is 1.1 mg/day. Over time, consuming very high amounts of iodine can cause thyroid gland enlargement and reduced production of thyroid hormone. These side effects are the same as those that occur when diets are deficient in iodine. Excess iodine is also associated with an increased risk of a form of thyroid cancer

Nuclear power plant accidents, such as the one that occurred after a major earthquake struck Japan in 2011, may release radioactive iodine (Iodine-131) into the environment. When people are exposed to radioactive iodine, the element can enter their bodies and be picked up by their thyroid glands.

For reasons that are unclear, non-Hispanic African-Americans are more likely than non-Hispanic white Americans to develop hypertension, especially early in life. Diets that limit sodium but contain adequate amounts of calcium, potassium, and magnesium may decrease high blood pressure, especially among African-Americans.

Obesity, a condition characterized by excessive amounts of body fat, is a major risk factor for hypertension. Physical inactivity is another leading risk factor related to hypertension. Obesity and physical inactivity are modifiable risk factors. By exercising and losing some excess fat, obese people who have hypertension often experience reductions in their blood pressure

Maintenance of intracellular water volume depends to a large extent on the intracellular concentration of potassium and phosphate ions.

On the other hand, maintenance of extracellular water volume depends primarily on the extracellular concentration of sodium and chloride ions.

Osmosis.

Osmosis is the diffusion of water through a selectively permeable membrane. Water moves from a compartment that is less concentrated to a compartment that has more material dissolved in it.

Iron-deficient people, particularly children and pregnant females, occasionally eat dirt or clay. Some medical researchers think they crave clay or dirt in response to being iron deficient.

Other researchers think eating these nonfood items is acceptable in some cultures, and the practice causes iron deficiency. Why? Substances in clay and dirt can interfere with iron absorption in the digestive tract. The practice of eating nonfood items is called pica (pié-kah).

Sources of Potassium Overall, fresh fruits, fruit juice, and vegetables are good dietary sources of potassium. Milk, whole grains, dried beans, and meats are also major contributors of potassium to American diets.

Overall, fresh fruits, fruit juice, and vegetables are good dietary sources of potassium. Milk, whole grains, dried beans, and meats are also major contributors of potassium to American diets.

Myoglobin is the iron-containing protein in muscle cells that controls oxygen uptake from red blood cells.

Oxygen is critical for energy metabolism.

Why Is Iodine Necessary?

People require iodine for normal thyroid function and for the production of thyroid hormones, collectively referred to as thyroid hormone.Thyroid hormone controls metabolic rate

A simple way to monitor bone mass is by tracking height. Losing an inch or more of adult height may be the first sign that a person has experienced fractures of the spine due to osteoporosis.17 If osteoporosis is suspected, a person can undergo special painless x-ray testing to determine the extent of bone loss. Individuals with a family history of osteoporosis, men who have low testosterone levels, and women who are postmenopausal should ask their physician if testing to determine bone mineral density is necessary.

People who are at high risk for or who already have osteoporosis may require medication to reduce their rate of bone loss. For postmenopausal women, taking calcium and vitamin D supplements may not reduce the risk of hip fractures.18 In this life stage, it may be too late to benefit from simply taking dietary supplements to prevent osteoporosis.

Exposure to a high amount of the radiation increases the risk of thyroid cancer, especially in children.

People who have iodine deficiency are more likely to accumulate the radioactive iodine in their thyroid glands than people who are not iodine deficient. To reduce the risk of thyroid cancer, people who are exposed to radioactive iodine can take supplements that contain 16 to 130 mg of potassium iodide, depending on their age, until the risk of extreme radiation exposure ends.The thyroid gland picks up the potassium iodide, which helps block the thyroid gland's uptake of the radioactive form of the element.

Each year, an estimated 1.5 million Americans experience an osteoporosis-related fracture. Half of women and one-fourth of men who are over 50 years of age will have such a fracture at some point.16 Many people do not realize their bones are becoming weaker and they have osteoporosis until they experience a fracture.

People with osteoporosis may break a bone by falling, or they may experience spontaneous fractures, in which the fragile bone shatters for no apparent reason. Osteoporosis-related fractures often involve the spine, hip, wrist, or ankle bones. In severe cases, bones in the upper spine fracture and then heal in an abnormally curved position, giving the obvious "widow's hump" appearance associated with osteoporosis

A person who is under physical or emotional stress can expect his or her blood pressure to rise temporarily. However, persistent systolic blood pressure readings of 120 mm Hg to 139 mm Hg and diastolic readings of 80 mm Hg to 89 mm Hg are signs of prehypertension.

People with prehypertension are more likely to develop hypertension than people with normal blood pressure. If a person's blood pressure persists at systolic values that are greater than or equal to (≥) 140 mm Hg and diastolic values that are ≥ 90 mm Hg, he or she has hypertension. T

Various factors influence a person's fluid input and output. Environmental factors such as temperature, humidity, and altitude can affect body water losses.

Physiological conditions, especially fever, vomiting, and diarrhea, as well as lifestyle practices, such as exercise habits and sodium and alcohol intakes, can also alter the body's fluid balance.

Certain foods from plants contain calcium, but the foods also contain phytic (fite′-ik) acid or oxalic (awk-sal′-ik) acid, naturally occurring substances that interfere with calcium absorption.

Phytic acid is a compound in whole grains and in certain seeds and beans. Spinach, collard greens, and sweet potatoes have high amounts of oxalic acid. In fact, rhubarb leaves are toxic because they contain such high amounts of the chemical.

Minerals, such as iron and calcium, are a group of elements in Earth's rocks, soils, and natural water sources. Plants, animals, and other living things cannot synthesize minerals.

Plants obtain the minerals they need from soil or fertilizer; animals generally obtain minerals when they consume plants and other animals or substances that contain these elements. About 15 mineral elements are essential nutrients. •Classified as micronutrients because they are required in mg or mcg amounts.

The FDA requires bottled water producers to

Process, bottle, hold and transport bottled water under sanitary conditions; Protect water sources from bacteria, chemicals, and other contaminants; Use quality control processes to ensure the bacteriological and chemical safety of the water; Sample and test both the source of water and the final product for contaminants

weight bearing activities

Regular weight-bearing activities provide numerous benefits to health, including strengthening bones. These older adults are performing tai chi, an activity that can improve balance and may reduce the likelihood of falling.

Cooking utensils may be a source of dietary iron. When acidic foods, such as tomato sauce, are cooked in cast-iron cookware, some iron migrates from the cookware and enters the food.

Replacing the heavy iron cookware with lighter stainless steel and aluminum pots and pans can reduce the amount of iron in diets.

The Dietary Approaches to Stop Hypertension (DASH) diet is low in sodium, total fat, saturated fat, and cholesterol, and high in fruits, vegetables, and low-fat dairy products.

Research indicates that people can lower their blood pressure and reduce their risk of CVD by following the DASH diet, losing excess body fat, and increasing their physical activity leve

Oral zinc lozenges are often promoted for treating the common cold

Results of studies, however, do not provide consistent scientific evidence that the lozenges reduce the severity or duration of cold symptoms.

Which of the following statements is true? Safety standards for bottled water are similar to those for tap water. Most brands of water bottled in the United States contain unsafe amounts of arsenic and lead. The EPA inspects and certifies water bottling facilities at least three times a year. The majority of Americans should drink bottled water because water from municipal systems is unsafe.

Safety standards for bottled water are similar to those for tap water.

Sodium Na

Salt is the primary source of sodium in American diets. The chemical commonly called "table salt" or simply "salt" is actually sodium chloride, a compound comprised of two minerals, sodium and chloride. A teaspoon of table salt supplies 2325 mg of sodium. (Unless otherwise noted, we will refer to sodium chloride simply as "salt" or "table salt.") The human digestive tract absorbs almost all of the sodium that is in foods and beverages.

The adult AI for potassium is 4700 mg per day. On average, Americans consume only about 2500 mg of potassium per day.People can raise their potassium intakes by increasing their consumption of fruits, vegetables, whole-grain breads and cereals, and low-fat and fat-free milk and milk products. This eating pattern is similar to the DASH diet. Most people consume 2700 mg/day

Salt substitutes often contain a type of salt called potassium chloride. People who have severe kidney diseases may accumulate toxic levels of potassium in their blood. Therefore, kidney disease patients should consult their physicians before using salt substitutes made with potassium chloride. Fruits and vegetables are recommended sources of potassium instead of potassium chloride

Selenium (Se)

Selenium is widespread in Earth's crust, but soils can vary widely in their content of the trace mineral. Areas of the western United States, including parts of Colorado and South Dakota, have unusually high concentrations of selenium in soil. Certain types of plants that grow in these places accumulate toxic levels of the mineral. Livestock that graze on the selenium-rich plants often ingest poisonous amounts of the trace mineral. In horses and cattle, selenium toxicity can cause hair and weight loss, malformed hooves that can separate from the animals' feet, muscle weakness and loss of muscular function (paralysis), and death.

Selenium Toxicity: The UL for selenium is 400 mcg/day. In the United States, selenium toxicity (selenosis) (sell′-in-o-sis) is rare. Chronic selenosis, however, can occur from drinking well water that naturally contains too much selenium.

Selenium toxicity can develop by taking megadoses of dietary supplements. In humans, signs and symptoms of chronic selenosis include brittle fingernails, loss of hair and nails, garlicky body odor, nausea, vomiting, and fatigue.

The excess water dilutes the sodium concentration of blood, disrupting water balance. As a result of the imbalance, too much water moves into cells, including brain cells.

Signs and symptoms of water intoxication may include dizziness, headache, confusion, inability to coordinate muscular movements, bizarre behavior, and seizures.8 If the condition is not detected early and treated effectively, coma and death can result.

Chromium Deficiency

Signs of chromium deficiency are impaired glucose tolerance and elevated blood cholesterol and triglyceride levels. The mechanism by which chromium influences cholesterol metabolism is not known but may involve enzymes that control the body's cholesterol production. Cases of chromium deficiency have been reported in people maintained on special-formula diets that did not contain chromium, as well as in severely malnourished children.

Simple diffusion

Simple diffusion can occur when there is a greater concentration of a substance in one region than in another. In this example, the dye is more concentrated on the left side of the container than on the right side. Eventually, the dye molecules diffuse (move) from where they are more concentrated to where they are less concentrated. The diffusion stops when the concentrations of dye molecules are equally distributed throughout the container.

Sodium depletion also can result from diarrhea or vomiting, especially in infants. In these cases, it is necessary to obtain medical care promptly to replace the lost fluids and electrolytes, because infants can develop dehydration rapidly

Sodium Toxicity The adult UL for sodium is 2300 mg/day. On average, Americans consumed more than 3300 mg of sodium per day in 2007-2008. (3400 in lecture notes) According to the results of numerous studies, high sodium intakes are associated with increased risk of hypertension. Thus, health experts generally recommend that Americans limit their sodium consumption.

water softening machines

Some homeowners install water-softening machines, because "hard water" interferes with the cleansing ability of soap and laundry detergent. Water softeners usually replace calcium and magnesium ions with sodium ions. Therefore, drinking softened water or using the treated water for preparing foods is not recommended because of its high sodium content.

calcium ions (Ca++) participate in blood clotting and sodium ions (Na+) help maintain fluid balance. Sodium, potassium, and chloride ions are among the ions that participate in acid-base balance.

Some ions, such as magnesium (Mg++) and copper (Cu++), are cofactors.

To survive, a human cell carefully controls the passage of substances through its plasma membrane.

Some materials, such as oxygen and carbon dioxide, easily pass through the cell's plasma membrane by simple diffusion. Large molecules, such as proteins, may be unable to pass through the cell's membrane, or they may need special carrier molecules to enter the cell.

The intestinal tract absorbs more of the heme iron than nonheme iron in foods

Some plant foods, such as spinach, contain nonheme iron, but oxalic acid in spinach binds to the mineral, reducing its absorption. Other naturally occurring compounds that reduce iron absorption include phytic acid in whole grains, tannins in tea, and substances that are chemically related to tannins in coffee.

he following suggestions can add more calcium to your diet:

Sprinkle grated low-fat cheeses on top of salads, bean or pasta dishes, and cooked vegetables. If you do not like the taste of plain fat-free milk, try adding a small amount of flavored syrup to the beverage. Two teaspoons of "lite" chocolate syrup add 50 kcal and some trace minerals to the milk. For a snack, melt a slice of low-fat cheese on half a whole-wheat bagel, whole-wheat crackers, or a slice of rye bread. If a recipe calls for water, substitute fat-free milk for water, if it is appropriate. For example, use fat-free milk when making cooked oatmeal or pancake batter. Add ¼ cup nonfat milk powder to 1 pound of raw ground meat when preparing hamburgers, meatballs, or meatloaf. Make homemade smoothies by blending plain low-fat yogurt with fresh or frozen fruit and fat-reduced ice cream or sherbet

the color of urine may be a useful indicator of hydration status.

Straw-colored (light yellow) urine can indicate adequate hydration, whereas dark-colored urine may be a sign of dehydration. However, the color of urine is not always a reliable guide for judging a person's hydration status.5 It is important to recognize that having urinary tract infections or ingesting certain medications, foods, and dietary supplements, especially those containing the B-vitamin riboflavin, can alter urine's color.

Humans require only about 180 mg of sodium per day, but the AI for adults under 51 years of age is 1500 mg/day. The AI for sodium does not apply for people who perspire heavily, such as marathon runners, or people who work in extremely hot conditions

Sweat contains small amounts of sodium, chloride, and some other minerals. People who perspire extensively can lose large amounts of these minerals in their sweat.

Your body constantly loses water through insensible perspiration, a form of water loss that is not the same as sweat. True. (p. 302) Ounce per ounce, cottage cheese contains more calcium than plain yogurt. False. (p. 312) Potassium, sodium, and chloride ions are involved in fluid balance. True. (p. 301) Selenium is an essential mineral. True. (p. 338) In general, plants are good sources of iron because the plant pigment chlorophyll contains iron. False

T True Your body constantly loses water through insensible perspiration, a form of water loss that is not the same as sweat. 2.False Ounce per ounce, cottage cheese contains less calcium than plain yogurt. 3.True Potassium, sodium, and chloride ions are among the ions involved in fluid balance. 4.True Selenium is an essential mineral. 5.False In general, plants are not good dietary sources of iron. The plant pigment chlorophyll contains magnesium not iron.

The body absorbs both forms of calcium to about the same extent. If you choose to take a calcium supplement, consider products that include vitamin D, because the vitamin enhances calcium absorption.

Taking only 500 mg of calcium at a time and ingesting the supplement with meals will also improve the mineral's absorption. Some calcium supplements contain lead, a nonnutrient mineral that is highly toxic. Therefore, it is important to avoid supplements made from dolomite, oyster shell, or bonemeal, because they are most likely to contain lead

Dietary Adequacy

The adult AIs for chromium are 25 mcg/day for young women and 35 mcg/day for young men. Well-balanced diets typically contain these amounts of chromium. On average, American adults consume diets that meet or exceed their AIs for chromium. Chromium picolinate may damage DNA, but more research is needed.

If we require 100 mg or more of a mineral per day, the mineral is classified as a major mineral; otherwise, the micronutrient is a trace mineral.

The body also contains very small amounts of other minerals, such as nickel and arsenic. The essential nature of this particular group of minerals has not been fully determined.

your body obtains water from beverages and foods, especially fruits, vegetables, and meats.

The body also makes some water as a result of its metabolism.

Several minerals, including lead and mercury, are often found in the human body, but they are environmental contaminants that have no known functions.

The body can eliminate most minerals in urine. However, exposure to excessive amounts of minerals can cause toxicity.

An average healthy adult consumes and produces approximately 2.5 quarts (2500 ml) of water daily

The body eliminates about 2.5 quarts of water in urine, exhaled air, feces, and perspiration. a healthy person's average daily water input equals his or her average daily losses (output).

Maintaining Normal Blood Calcium Levels

The body has complex hormonal systems to maintain calcium homeostasis. The thyroid and parathyroid glands help regulate blood calcium levels. In response to falling blood calcium levels, the parathyroid glands secrete parathyroid hormone (PTH), which signals special bone cells called osteoclasts to tear down bone tissue. This process releases calcium from bones so the mineral can enter the bloodstream. PTH also works with vitamin D to increase intestinal calcium absorption and reduce calcium excretion in urine

Body Water Distribution

The body has two major fluid compartments—intracellular water and extracellular water. Intracellular water is inside cells. Extracellular water surrounds cells (tissue fluid) or is the fluid portion of blood (plasma). About two-thirds of the body's water is in the intracellular compartment.

Maintaining proper hydration.Cells, such as red blood cells, need to maintain their fluid balance. Changes in the normal concentrations of ions can cause water to shift out of one compartment and move into the other.

The cell in beaker (a) is placed in a solution that contains few sodium ions (Na+) in relation to the concentration of Na+ in the cell. As a result, water moves from the solution and into the red blood cell. The cell can swell and burst. The solution in beaker (b) has an excess of sodium ions (Na+) compared to the concentration of Na+ inside the cell. Water moves out of the red blood cell placed in beaker (b). As a result, the cell shrinks, and can die.

Osmosis is the diffusion of water through a selectively permeable membrane, such as the plasma membrane of a human cell.

The concentration of substances dissolved in the water, such as sodium ions or glucose, influences osmosis. Water moves from a region that has less material dissolved in it (dilute) to a region that has more material dissolved in it. The diffusion stops when the concentrations of the material on either side of the plasma membrane are equal.

Most Americans' diets meet the RDA for selenium. In the United States, selenium deficiency is uncommon, but the condition may occur in people who have serious digestive tract conditions that interfere with the mineral's absorption. Selenium deficiency reduces thyroid gland activity and can lead to goiter. Adequacy •Adult selenium RDA = 200 mcg/d •Most Americans meet RDA •Deficiency •May occur with severe digestive tract conditions •Toxicity •Upper Limit (UL) = 400 mcg/d •Known as selenosis

The deficiency also depresses immune system function and may contribute to the development of heart disease and cancer. In parts of China where the soil lacks selenium and the population consumes locally produced foods, diets typically contain inadequate amounts of selenium. Certain types of cancer and a form of heart disease are common in these areas of China. There is not enough scientific evidence, however, to support the use of selenium supplements to prevent or treat cancer or CVD

Although bottled water is safe to drink, the plastic used to contain it may have toxic effects on health. Bisphenol (biss'-feen-ol) A, which is also called BPA, is a chemical used to make polycarbonate plastics and epoxy resins. Polycarbonate plastics are in many consumer products that come in contact with foods and beverages, including some water bottles and baby bottles.

The epoxy resin that contains BPA is used to coat the inside of certain food cans. The coating prevents the can's metal from coming in contact with and being damaged by the food. However, BPA can leach from polycarbonate plastic containers or epoxy resin-coated cans and enter the food or beverage stored within them.

About 15 mineral elements have known functions in the body and are necessary for human health. The body requires these particular micronutrients in milligram or microgram amounts.

The essential minerals are classified into two groups—major minerals and trace minerals

The best way to detect hypertension is to have regular blood pressure screenings. When you have your blood pressure determined, two measurements are actually taken.

The first measurement is the systolic pressure, which is the maximum blood pressure within an artery. This value occurs when the ventricles, the heart's pumping chambers, contract. The second measurement is the diastolic pressure, which measures the pressure in an artery when the ventricles relax between contractions. The systolic value is always higher than the diastolic value. For adults, healthy blood pressure readings are less than 120/80 millimeters of mercury (mm Hg). After having your blood pressure measured, ask the clinician for your systolic and diastolic readings and keep a record of the values.

Chromium Toxicity

The form of chromium that is naturally in foods has not been shown to produce toxicity, so no UL has been set for the trace mineral. The long-term safety of taking various chromium supplements is unknown. Data from a study using cells of mice indicated chromium picolinate may damage human DNA.This finding raises concern, because damaged DNA can result in cancer. Therefore, taking supplemental chromium may be risky

Chromium (Cr)

The importance of chromium as an essential trace mineral in human diets has been recognized only for about the past 40 years. The results of scientific studies suggest that chromium plays an important role in maintaining proper carbohydrate and lipid metabolism. The human digestive tract absorbs only about 0.4 to 2.5% of the chromium in foods; the remainder is excreted in the feces. Thus, the concentration of chromium in human tissues is generally low.

Thirst is the primary regulator of fluid intake.2 The thirst response alerts you to the need to replenish water that was lost by sweating and other means.

The majority of healthy people meet their AI for water by letting thirst be their guide.4 Thirst stimulates people to drink fluids before severe dehydration occurs. However, people who are dehydrated and older than 60 years of age do not sense thirst as accurately as younger adults

Other Sources of Minerals

The tap water in your community may be a source of minerals that you may have overlooked. "Hard" water naturally contains a variety of minerals, including calcium, magnesium, sulfur, iron, and zinc. Water with high mineral content often tastes and smells unpleasant. Many people drink bottled water as a substitute for tap water because they think bottled water tastes better and it is safer.

Thyroid and parathyroid glands.

The thyroid gland has the four parathyroid glands imbedded in the back (posterior) of the organ. Hormones secreted by the thyroid and parathyroid glands help regulate blood calcium levels.

In the United States, rates of iron deficiency related disorders in infants and preschool children have decreased over the past 30 years.

The use of iron-fortified formulas and cereals in the Special Supplemental Nutrition Program for Women, Infants, and Children (the WIC program) may be responsible for improving this aspect of children's health.

Have you ever noticed that your weight increases by a few pounds after you have eaten a lot of salty foods and then consumed beverages?

The weight gain is due to a temporary increase in body water volume. If you resume eating foods that supply your usual intake of sodium, your kidneys will eliminate the excess sodium and water in urine within a day. As your body regains its normal fluid balance, your weight also returns to normal.

Can Too Much Water Be Toxic?

There is no Upper Limit (UL) for water. Water intoxication, however, can occur when an excessive amount of water is consumed in a short time period or the kidneys have difficulty filtering water from blood.

The Adequate Intake (AI) for total water intake is approximately 11 cups (2.7 L) for young women and approximately 15.5 cups (3.7 L) for young men.

These amounts do not need to be consumed in the form of water. Other sources of water include fruit juice, milk, soup, coffee, tea, soft drinks, and flavored bottled water. Most solid foods also contain some water. Fruits and vegetables appear to be solid, but they generally contain 60 to 95% water weight.

Bottled water is sealed in containers and has no added ingredients other than a substance that prevents the growth of microbes, such as bacteria. Bottled water may have fluoride added, but amounts must meet FDA guidelines. If bottled water manufacturers add flavorings or other ingredients to their products, the name of the product must indicate the added ingredients—"Bottled Water with Cherry Flavor," for example.

These drinks are often called "flavored water beverages." Flavored waters may simply contain additives that make the beverage taste good, but a growing number of flavored waters also have added nutrients other than sugars, such as sodium, potassium, and amino acids. The beverage's label must identify the additives in the list of ingredients.

Zinc deficiency in young men.Zinc is necessary for normal physical growth and sexual development.

This 16-year-old Egyptian boy experienced stunted growth and impaired sexual maturation as a result of a zinc-deficient diet.

The layer of fat that is under the skin (subcutaneous fat) interferes with the transfer of heat to the skin.

This explains why overweight people who are in warm conditions are more uncomfortable and perspire more than slender people.

Throughout the world, millions of people are at risk of iodine deficiency. Pregnant women who are iodine deficient have high risk of stillbirths (giving birth to a dead infant) or low-birth-weight babies. During fetal life, thyroid hormone is crucial for normal brain development.

Thus, infants of iodine-deficient women are likely to be born with a condition called cretinism (kre′-tin-ih-zim). Babies with cretinism have permanent brain damage, reduced intellectual functioning, and growth retardation. Worldwide, iodine deficiency is the most common cause of preventable intellectual disability.42 Pregnant women can reduce the risk of giving birth to infants with cretinism by consuming adequate amounts of iodine throughout pregnancy.

For adult men, the RDA for iron is 8 mg per day; for adult women between 19 and 50 years of age, the RDA for iron is 18 mg/day. The average daily intake for American men is about 17.5 mg, whereas the average daily intake for American women is about 13.0 mg/day

Thus, women between 19 and 50 years of age are more likely than men to have inadequate iron intakes.

The adult RDA for calcium ranges from 1000 to 1200 mg/day. For children and adolescents between the ages of 9 and 18, the RDA is higher (1300 mg/day) to allow for increases in bone mass during growth and development. In the United States, average calcium intakes were approximately 1040 mg/day for men and 833 mg/day for women in 2007-2008

Thus, women consumed less than the RDA for calcium, whereas most men had intakes that were roughly equivalent to the RDA. Total vegetarians (vegans) and people who are lactose intolerant are at risk of calcium deficiency, because they often avoid consuming milk and milk products, the most reliable dietary sources of calcium.

edema (eh-dee′-mah) occurs when an excessive amount of water moves into the space surrounding cells

To function normally, the body must maintain intracellular and extracellular water volumes within certain limits.

In some instances, the digestive tract absorbs more minerals than the body needs, but the excess is excreted, primarily in urine or feces. In other instances, the body stores the extra minerals in the liver, bones, or other tissues.

Toxicity signs and symptoms occur when minerals accumulate in the body to such an extent that they interfere with the functioning of cells. Under normal conditions, the human body does not store large quantities of most minerals, and it loses small amounts of these essential elements every day.

Even if your blood pressure is normal now, it is important to have regular blood pressure checks as you grow older, because the risk of hypertension increases with age. In the United States, approximately 70% of people who are 65 years of age and older have hypertension. Children and young adults, however, are not immune to hypertension.

Treatment for hypertension usually includes taking certain medications, following dietary modifications, and making some other lifestyle changes

Many people who have HH experience vague symptoms or no symptoms at all. If the disease is not detected early and treated effectively, the organ damage resulting from the condition can be deadly.

Treatment usually includes visiting a clinic periodically to have blood removed. This process stimulates the tissues that produce red blood cells to use storage iron for hemoglobin production. People with HH should avoid taking dietary supplements that contain iron.

Raw vegetables, particularly turnips, cabbage, brussels sprouts, cauliflower, and broccoli, contain goitrogens. These compounds inhibit iodide metabolism by the thyroid gland and, as a result, reduce thyroid hormone production.

Unless people eat large amounts of raw vegetables that contain goitrogens or they are iodide deficient, they do not need to be concerned about eating these foods. Furthermore, cooking vegetables destroys goitrogens.

Total vegetarians have a higher risk of iron deficiency related disorders than people who eat meat, because meat provides heme iron. Combining a small amount of meat with plant foods improves the bioavailability of the plant's nonheme iron.

Vegetarians, however, may reject recipes that include any meat, especially red meats. Some plant foods contain high amounts of oxalic acid and phytic acid, substances that can depress iron absorption. On the other hand, vegetarian diets usually are rich in vitamin C, a factor that increases nonheme iron absorption. Thus, vegetarians should consume vitamin C-rich foods along with plant foods, especially those that contain appreciable amounts of iron, such as spinach, lentils, and soybeans. Eating iron-fortified ready-to-eat cereals can also be helpful for vegetarians, even though the form of iron used to fortify cereals is not as well absorbed as heme iron. Finally, vegetarians can take a multivitamin and mineral supplement that contains iron to ensure their iron and other mineral intakes are adequate.

water conservation

Water conservation occurs when a person is hot & perspires heavily. •Hormones that participate in sodium & water conservation include: -Antidiuretic hormone (ADH) -Aldosterone

Water

Water is a simple compound; a molecule of water is comprised of two hydrogen atoms and one oxygen atom (H2O). Water does not need to be digested, and it is easily absorbed by the intestinal tract.

A person's percentage of body weight that is water declines from birth to old age.

Water may comprise only 45% of a typical older adult's weight

Calcium is added to a variety of foods, including fortified orange juice, margarine, soy milk, cereals, and breakfast bars. Another source of calcium is soybean curd (tofu) that is made with calcium sulfate.

You can read labels to learn about the calcium content of packaged foods; the information is a mandatory component of the Nutrition Facts panel.

water is essential

You can survive for weeks, even months, if your diet lacks carbohydrates, lipids, proteins, and vitamins. But if you do not have any water, your life will end within a week or two.

Why Is Zinc Necessary?

Zinc is a component of about 100 enzymes. Zinc is necessary for wound healing, the sense of taste and smell, DNA synthesis, and proper functioning of the immune system. Zinc is also essential for growth and development during pregnancy, childhood, and adolescence. Needed for: •Wound healing •Normal of taste and smell •DNA synthesis •Immune function

Sources of Zinc

Zinc is widespread in foods. Red meat and poultry products supply most of the zinc in the typical American's diet.

Excessive alcohol intake increases the risk of hypertension. To reduce their chances of developing high blood pressure, people should avoid alcohol or limit their consumption to two or fewer drinks/day (men) and only one drink/day (women and older adults). Other important risk factors for hypertension include having diabetes and using tobacco.

a high-sodium diet is associated with increased risk of hypertension, and in some cases, such diets can be a cause of hypertension.25 Many medical researchers think some people are genetically "sodium sensitive." A person who is sodium sensitive is more likely to develop hypertension as a result of consuming a high-sodium diet than an individual who lacks this sensitivity. The kidneys of a sodium-sensitive person may be unable to eliminate excess sodium as effectively as the kidneys of a healthy person. The excess sodium causes the body to retain water, and blood volume and pressure increase as a result.

Water is

a solvent a major component of blood, saliva, sweat, tears, mucous, joint fluid removes waste transports substances lubricates tissues regulates temperature digests food participates in chemical reactions maintains proper blood pH

Bone remodeling occurs throughout life, and as a result of this process, most of your skeleton is replaced

about every 10 years

During pregnancy, a woman's need for iron increases as her blood supply expands and new tissues are added to both her body and that of her fetus. Pregnant women who suffer from iron deficiency anemia have higher risk of dying during pregnancy than healthy pregnant women.

anemic pregnant women are also more likely to give birth to premature or low-birth-weight infants. Premature babies are born before the 37th week of pregnancy; normally, pregnancies last about 40 weeks from the date of the mother's last menstrual period. A low-birth-weight baby weighs less than 5½ pounds at birth. Compared to healthy newborns, premature or low-birth-weight infants are more likely to die during their first year of life.

best source of magnesium

beans

Sources of heme iron include fortified grain products. beef. spinach. cast-iron cookware.

beef

Water Conservation

body water depletion is called dehydration. Dehydration can be a life-threatening condition.

Canned fish with edible soft bones, such as sardines and salmon, are good calcium sources. When making salmon patties using canned fish, mash up the bones along with the salmon.

bones are soft so you don't notice them in the cooked product

Which of the following foods is not a good source of calcium? butter American cheese canned sardines kale

butter

nerve transmission

calcium, sodium, potassium

Major minerals

calcium, sodium, potassium, and magnesium because Americans tend to consume too much or too little of them. Unless otherwise noted, RDA/AI values are for adults, excluding pregnant or breastfeeding women.

Certain leafy vegetables, such as bok choy and collard greens,

contain calcium that is bioavailable.

Changes in the normal concentrations of these ions can cause water to shift out of one compartment and move into the other.

if extracellular fluid has fewer-than-normal sodium ions, water moves from the extracellular compartment into cells. When this occurs, the cells swell and can burst

Iron Toxicity The UL for iron is 45 mg/day. Although not having enough iron in the body interferes with normal growth, development, and functioning, ingesting too much iron poses the risk of toxicity. Between 1988 and 1997, American children under 6 years of age died as a result of accidentally taking too many iron-containing dietary supplements. Early signs of acute iron poisoning include vomiting and diarrhea that may progress to coma and death.

in 1997, the FDA required a warning statement on the packaging of iron supplements to reduce the number of iron poisoning cases among young children. The agency also required unit-dose packaging of oral iron supplements that contained 30 mg of iron or more per dose. The individually wrapped supplements were designed to make it difficult for young children to ingest large quantities of the supplements at a time. After these rules were instituted, only one child died from iron poisoning between 1998 and 2002. In 2003, however, a federal court ruled that the FDA did not have the legal authority to require special unit-dose packaging of iron supplements. The agency, however, could continue to require warning statements on supplement labels. Iron Overload: Hereditary Hemochromatosis -Common hereditary disorder resulting in excess iron absorption

If the extracellular fluid has an excess of sodium ions, sodium ions move into cells. intracellular fluid moves to the outside of cells. phosphate and calcium ions are eliminated in feces. blood levels of arsenic and oxalate increase.

intracellular fluid moves to the outside of cells.

In the United States, table salt is often fortified with iron. selenium. potassium. iodide.

iodine

Worldwide, the most common nutrient deficiency disorder is ______ deficiency. iodine cobalt iron calcium

iron

Osteoporosis

is a chronic disease characterized by low bone mass and reduced bone structure. People with osteoporosis have weak bones that are susceptible to fractures. In the United States, osteoporosis is a major public health problem. More than 10 million Americans have osteoporosis, and another 34 million are at risk of the disease because they have low bone mass.15 Most people with osteoporosis are older adult women.

Water is a major solvent

many substances, including glucose, dissolve in water. Water often participates directly in chemical reactions, such as those involved in digesting food. Water's other physiological roles include transporting substances, removing waste products, lubricating tissues, and regulating body temperature and acid-base balance (proper blood pH). Furthermore, water is a major component of blood, saliva, sweat, tears, mucus, and the fluid in joints.

Which of the following populations has the highest risk of hypertension? people with African-American ancestry young, physically active Asian men Hispanic women who do not drink alcohol young adults who consume high amounts of fruit

people with African-American ancestry

Henry is concerned about his risk of osteoporosis. Which of the following characteristics is a modifiable risk factor for this chronic condition? family history racial/ethnic background physical activity level age

physical activity level

to reduce your sodium intake, consider taking these actions:

repare homemade meals and snacks as much as possible so you have control over your salt intake. Do not add salt while preparing foods, even though instructions tell you to "add salt." Taste your food before salting it. Adjust to eating foods with less salt in them. Do not keep a salt shaker on your table. Read the Nutrition Facts panels before purchasing packaged foods to determine sodium contents of the items. When ordering items in restaurants, request that no salt be added to your food while it is being prepared.

The primary source of sodium in the typical American's diet is bottled water. unprocessed food. fruit. salt.

salt

Healthy adults absorb about 30% of the calcium in foods, but this percentage varies, depending on the type of food.15 During stages of life when the body needs extra calcium

such as infancy and pregnancy—absorption can be as high as 60%. Vitamin D enhances calcium absorption.

if extracellular fluid has an excess of sodium ions, water moves out of cells.

the cells shrink and die because they lack enough intracellular fluid to function

Which of the following foods has the lowest percentage of water? tomatoes oranges whole-grain bread vegetable oil

vegetable oil

Membrane Transport

water helps cells obtain materials from their environment and eliminate wastes.

Healthy people rarely drink enough water to become intoxicated.

water intoxication can develop in people with disorders that interfere with the kidney's ability to excrete water normally. Marathon runners who consume large amounts of plain water in an effort to keep hydrated during competition may be at risk of water intoxication.

least amount of selenium

white bread

vegetarian sources of iron

whole grain cereal, beans, mushrooms