Chapter 1 – Title of Chapter - Nutrition Gardener



Chapter 13 – The Trace Minerals

Learning Objectives

1. Identify the functions of iron in the body.

2. Identify factors that increase and decrease iron absorption from the diet.

3. Describe the transport and storage of iron in the body.

4. Discuss populations at risk for iron deficiency and identify symptoms of iron deficiency and iron toxicity.

5. Identify food sources of iron and determine the amount needed daily.

6. Discuss the role of zinc in the body and the absorption, metabolism, and transport of zinc.

7. Describe zinc deficiency, toxicity, and recommended dietary intake.

8. Identify major food sources of zinc and discuss the use of zinc supplements.

9. Describe the roles of iodine in the body and the deficiency diseases seen with inadequate intake.

10. Describe the effects of excess iodine intake.

11. Identify food sources of iodine and the impact of iodization of salt.

12. Describe the uses of selenium in the body and the role of selenium in cancer protection.

13. Identify food sources of selenium and the amount needed daily.

14. Describe the role of copper in the body and major food sources of copper.

15. Describe the role of manganese in the body and the major sources of the trace mineral.

16. Explain the uses of fluoride in the body and its role in dental caries prevention.

17. Identify the effects of fluoride toxicity and the major sources of fluoride to the body.

18. Describe the uses of chromium in the body and its relationship to diabetes.

19. Identify the food sources of chromium and the role of chromium supplementation for weight control.

20. Discuss the contaminant minerals, including lead, and symptoms of toxicity.

21. Describe the roles of phytochemicals in food and the physiological effects of phytochemicals in the body.

22. List major phytochemicals that might protect the body from cancer and heart disease.

23. Describe functional foods and their role in disease prevention.

24. Identify methods to help the consumer evaluate the safety and effectiveness of functional foods.

Lecture Presentation Outline

I. The Trace Minerals—An Overview

Trace minerals are needed in very small quantities in the human body. They perform many essential functions important to health. Toxic levels can easily be reached with the use of supplements. Humans can get the amounts of trace minerals needed by consuming a wide variety of foods.

A. Food Sources

1. Depends on soil and water composition.

2. Depends on processing.

3. Bioavailability.

4. Wide variety of unprocessed foods.

B. Deficiencies

1. Severe deficiencies of some minerals are easy to recognize, while others can be difficult to diagnose.

2. Mild deficiencies are easily overlooked.

3. Deficiencies have wide-reaching effects.

4. Deficiencies affect all ages, but in children, they can affect growth.

C. Toxicities

1. Do not exceed Tolerable Upper Intake Levels.

2. FDA does not limit amounts in supplements.

3. Do not exceed 100% Daily Values.

D. Interactions

1. Common and coordinated to meet body needs.

2. Can lead to nutrient imbalances.

II. Iron

Iron is an essential nutrient found in the body as a part of hemoglobin and myoglobin. Iron is used for energy metabolism and enzyme activity. Special proteins assist with iron absorption, transport, and storage. Both iron deficiency and iron toxicity cause damage, so balance is important. Heme iron is better absorbed but nonheme iron absorption can be enhanced.

A. Iron Roles in the Body

1. Ferrous iron is reduced and has a net positive charge of two.

2. Ferric iron is oxidized and has a net positive charge of three.

3. Cofactor in oxidation-reduction reactions.

4. Utilization of energy in cell metabolism.

5. Part of the protein hemoglobin, which carries oxygen in the blood.

6. Part of the protein myoglobin in the muscles, which makes oxygen available for muscle contractions.

B. Iron Absorption and Metabolism

1. Iron Absorption

a. The protein ferritin stores iron in the mucosal cells lining the digestive tract.

b. Transfers iron to mucosal transferrin.

c. Transfers iron to blood transferrin.

d. Transports iron to the cells.

e. Excreted and replaced as needed.

2. Heme and Nonheme Iron

a. Heme iron

1. Found in foods that are from the flesh of animals (meat, poultry, and fish).

2. Represents only 10% of a day’s iron consumption, but has an absorption rate of 25%.

b. Nonheme iron

1. Found in plant-derived and animal-derived foods.

2. Has an absorption rate of 17%.

3. Absorption-Enhancing Factors

a. MFP factor enhances the absorption of nonheme iron.

b. When nonheme iron is consumed with vitamin C at the same meal, absorption of iron increases.

4. Absorption-Inhibiting Factors

a. Phytates from legumes, whole grains, and rice.

b. Vegetable proteins in soybeans, legumes, and nuts.

c. Calcium in milk.

d. Tannic acid and other polyphenols in tea, coffee, grains, oregano, and red wine.

5. Dietary Factors Combined

a. Difficult to assess iron absorption with meal consumption.

b. Most relevant factors are MFP factor and vitamin C in enhancing absorption and phytates in inhibiting absorption.

6. Individual Variation

a. Dietary factors.

b. Health status.

c. Stage in life cycle.

d. Iron status.

7. Iron Transport and Storage

a. Surplus is stored in bone marrow, spleen, and liver.

b. Hemosiderin is a storage protein used when concentrations of iron are extremely high.

c. Storing excess iron is a protective measure because iron can act as a free radical.

8. Iron Recycling

a. The liver and spleen dismantle red blood cells and package iron into transferrin.

b. Transferrin carries iron in the blood.

c. Bone marrow incorporates iron into hemoglobin and stores iron as ferritin.

d. Iron-containing hemoglobin carries oxygen in the blood.

e. Iron is lost when bleeding occurs and through the GI tract.

9. Iron Balance

a. The absorption, transport, storage, recycling, and loss of iron must be regulated in order to maintain iron balance.

b. Hepcidin is a hormone that inhibits the absorption and transport of iron to keep blood levels within normal ranges.

C. Iron deficiency is the most common nutrient deficiency.

1. Symptoms

a. Anemia: weakness, fatigue, headaches, and impaired work and cognitive performance.

b. Impaired immunity.

c. Pale skin, nail beds, mucous membranes, and palm creases.

d. Concave nails.

e. Inability to regulate body temperature.

2. Vulnerable Stages of Life – Iron-deficiency anemia can affect individuals in many stages of life.

a. Women in reproductive years due to menstruation.

b. Pregnant women due to the needs of the infant, increases in blood volume, and loss of blood during the birthing process.

c. Infants and young children due to rapid growth.

d. Teenagers due to rapid growth in males and menstruation in females.

3. Blood Losses

a. Can be from non-obvious sources such as a bleeding ulcer.

b. Malaria and parasites.

c. Giving a pint of blood results in a loss of about 2.5 mg iron.

d. Menstruation.

4. Assessment of Iron Deficiency

a. Stage 1 is when iron stores diminish and is measured by serum ferritin levels.

b. Stage 2 is when transport iron decreases and is measured by transferrin saturation.

c. Stage 3 is when hemoglobin production declines, erythrocyte protoporphyrin accumulates, and hematocrit declines. Hemoglobin and hematocrit are late indicators of iron status.

5. Iron Deficiency and Anemia

a. Iron deficiency is when there is depletion of the body’s iron stores.

b. Iron-deficiency anemia is the severe depletion of iron stores. Also called microcytic (small) hypochromic (pale) anemia.

6. Iron Deficiency and Behavior

a. Energy metabolism is impaired.

b. Neurotransmitter synthesis is reduced.

c. Physical work capacity and mental productivity are reduced.

d. Symptoms of a deficiency may be confused with behavioral issues.

7. Iron Deficiency and Pica

a. Generally found in women and children from low-income groups.

b. Eating ice, chalk, starch, and other nonfood substances.

c. Eating nonfood substances will not correct the deficiency.

D. Iron Toxicity

1. Iron Overload

a. Hemochromatosis is generally a genetic disorder that enhances iron absorption and may be caused by a lack of hepcidin.

b. Iron overload can also be caused by:

1. Repeated blood transfusions.

2. Massive doses of supplemental iron.

3. Rare metabolic disorders.

c. Hemosiderosis may develop from excessive iron where there are large deposits of hemosiderin in the liver, heart, joints, and other tissues.

d. Symptoms of iron overload include infections, fatigue, joint pain, skin pigmentation, and organ damage.

e. Problems include liver tissue damage and infections.

f. Higher risk of diabetes, liver cancer, heart disease, and arthritis.

g. More common in men then in women.

h. Treated with chelation therapy.

2. Iron and Heart Disease – may be a link to high iron stores.

3. Iron and Cancer – may be a link with free radical activity resulting in damage to DNA.

4. Iron Poisoning

a. UL for adults: 45 mg/day.

b. Accidental supplement poisoning in children.

c. Symptoms include nausea, vomiting, diarrhea, rapid heartbeat, weak pulse, dizziness, shock, and confusion.

E. Iron Recommendations and Sources

1. Recommended Iron Intakes

a. RDA Men: 8 mg/day for adults 19-50 years of age.

b. RDA Women: 18 mg/day for adults 19-50 years of age.

c. RDA Women: 8 mg/day for adults over 51 years of age.

d. Vegetarians need 1.8 times as much iron because of low bioavailability.

2. Iron in Foods

a. Red meats, fish, poultry, and shellfish.

b. Eggs.

c. Legumes..

d. Grain products (whole-grain, enriched, and fortified breads and cereals).

e. Dark greens and dried fruits.

3. Iron-Enriched Foods

a. Often added to grain foods.

b. Not absorbed as well.

4. Maximizing Iron Absorption

a. Bioavailability is high in meats, fish, and poultry.

b. Bioavailability is intermediate in grains and legumes.

c. Bioavailability is low in vegetables.

d. Combined effect of enhancing and inhibiting factors.

F. Iron Contamination and Supplementation

1. Contamination Iron

a. Food prepared in iron cookware takes up iron salts.

b. Acidic foods and long cooking times increase uptake of iron salts.

2. Iron Supplements

a. Best absorbable form is ferrous sulfate or an iron chelate.

b. Take on empty stomach and with liquids other than milk, tea, or coffee.

c. Vitamin C enhances food iron absorption, not supplement absorption.

d. Side effect of constipation.

e. Should only be taken when prescribed by a health care provider.

III. Zinc

Zinc is important in a multitude of chemical reactions in the body. The best sources of dietary zinc are protein-rich foods. Zinc from pancreatic secretions is also available for absorption. Phytates and fiber can bind zinc, therefore limiting absorption. A special binding protein monitors the absorption of zinc. Zinc deficiency symptoms include growth retardation and sexual immaturity.

A. Zinc Roles in the Body

1. Supports the work of metalloenzymes.

a. Helps to make parts of DNA and RNA.

b. Manufactures heme for hemoglobin.

c. Participates in essential fatty acid metabolism.

d. Releases vitamin A from liver stores.

e. Metabolizes carbohydrates.

f. Synthesizes proteins.

g. Metabolizes alcohol.

h. Disposes of damaging free radicals.

2. Involved in growth, development, and immune function.

3. Affects platelets in blood clotting and wound healing.

4. Needed to produce the retinal form of vitamin A.

5. Affects thyroid hormone function.

6. Influences behavior and learning performance.

7. Taste perception.

8. Wound healing.

9. Sperm development.

10. Fetal development.

B. Zinc Absorption and Metabolism

1. Zinc Absorption

a. Rate of absorption depends on zinc status; when more is needed, more will be absorbed.

b. Phytates bind zinc and reduce absorption.

c. Metallothionein is a special protein that holds zinc in storage.

2. Zinc Recycling

a. Enteropancreatic circulation – travels from the pancreas to the intestines and back.

b. Losses occur in the feces, urine, shedding of skin, hair, sweat, menstrual fluids, and semen.

3. Zinc Transport

a. Transported by the protein albumin.

b. Binds to transferrin.

c. Excessive iron and copper can lead to a zinc deficiency and excessive zinc can lead to an iron and copper deficiency.

C. Zinc Deficiency

1. Not widespread.

2. Occurs in pregnant women, young children, the elderly, and the poor.

3. Symptoms of deficiency

a. Growth retardation.

b. Delayed sexual maturation.

c. Impaired immune function.

d. Hair loss, eye and skin lesions.

e. Altered taste, loss of appetite, and delayed wound healing.

D. Zinc Toxicity

1. UL for Adults: 40 mg/day.

2. Symptoms

a. Loss of appetite.

b. Impaired immunity.

c. Low HDL.

d. Copper and iron deficiencies.

e. Vomiting and diarrhea.

f. Exhaustion.

g. Headaches.

E. Zinc Recommendations and Sources

1. Recommended intakes

a. RDA Men: 11 mg/day.

b. RDA Women: 8 mg/day.

2. Zinc in foods

a. Protein-containing foods such as shellfish, meats, poultry, milk, and cheese.

b. Whole grains, legumes, and some fortified cereals.

F. Zinc Supplementation

1. Developing countries use zinc to reduce incidence of death associated with diarrhea.

2. Zinc lozenges for the common cold are controversial and inconclusive.

IV. Iodine

Iodide is an essential component of the thyroid hormone that helps to regulate metabolism. Iodine deficiency can cause simple goiter and cretinism. The iodization of salt has greatly reduced iodine deficiency in the United States and Canada.

A. Iodide Roles in the Body

1. Component of two thyroid hormones (T3 and T4).

2. Regulates body temperature, growth, development, metabolic rate, nerve and muscle function, reproduction, and blood cell production.

B. Iodine Deficiency

1. Simple goiter is the enlargement of the thyroid gland caused by iodine deficiency. Goiter is enlargement of the thyroid gland due to malfunction of the gland, iodine deficiency, or overconsumption of goitrogens.

2. Goitrogen (antithyroid) overconsumption – naturally occurring in cabbage, spinach, radishes, rutabaga, soybeans, peanuts, peaches, and strawberries.

3. Cretinism is a congenital disease characterized by mental and physical retardation and commonly caused by maternal iodine deficiency during pregnancy.

C. Iodine Toxicity

1. UL 1100 (g/day.

2. Symptoms include underactive thyroid gland, elevated TSH, and goiter.

3. Supplement use, medications, and excessive iodine from foods.

D. Iodine Recommendations and Sources

1. Recommendations – Adults: 150 (g/day.

2. Sources

a. Iodized salt.

b. Seafood.

c. Bread and dairy products.

d. Plants grown in iodine-rich soils.

e. Animals that feed on plants grown in iodine-rich soils.

V. Selenium

Selenium is an antioxidant nutrient associated with protein foods. It may provide some protection against certain types of cancer.

A. Selenium Roles in the Body

1. Defends against oxidation.

2. Regulates thyroid hormone.

B. Selenium Deficiency

1. Keshan disease – a pre-disposition to heart disease where a virus causes the cardiac tissue to become fibrous.

2. Prevalent in regions of China because the soil is low in selenium.

C. Selenium and Cancer

1. May protect against certain forms of cancer.

2. Inconclusive evidence and more research is needed.

3. Food sources are better than supplements.

D. Selenium Recommendations and Sources

1. Recommendations – Adults: 55 (g/day.

2. Sources include seafood, meat, whole grains, and vegetables (depends on soil content).

E. Selenium Toxicity

1. UL for Adults: 400 (g/day.

2. Symptoms

a. Loss and brittleness of hair and nails.

b. Skin rash, fatigue, irritability, and nervous system disorders.

c. Garlic breath odor.

VI. Copper

Copper is a component of several enzymes associated with oxygen or oxidation. Copper deficiency is rare. There are some diseases associated with excessive intakes. Food sources of copper include legumes, whole grains, and seafood.

A. Copper Roles in the Body

1. Absorption and use of iron in the formation of hemoglobin.

2. Part of several enzymes.

3. Some copper-containing enzymes are antioxidants.

4. Required for many metabolic reactions.

B. Copper Deficiency and Toxicity

1. Deficiency is rare in the U.S.; however, symptoms include anemia and bone abnormalities.

2. In Menkes disease, copper cannot be released into the circulation.

3. Toxicity

a. UL for Adults: 10,000 (g/day (10 mg/day).

b. In Wilson’s disease, copper builds up in the liver and brain.

c. Excessive intake from supplements can cause liver damage.

C. Copper Recommendations and Sources

1. Recommendations – Adults: 900 (g/day.

2. Sources

a. Seafood, nuts, seeds, and legumes.

b. Whole grains.

c. In houses with copper plumbing, water can be a source.

VII. Manganese

Manganese is a cofactor for several enzymes involved in bone formation and various metabolic processes. Deficiencies are rare and toxicities are associated with environmental contamination. Manganese is found in many foods.

A. Manganese Roles in the Body

1. Cofactor for several enzymes.

2. Assists in bone formation.

3. Pyruvate conversion.

B. Manganese Deficiency and Toxicity

1. Deficiency symptoms are rare.

2. Phytates, calcium, and iron limit absorption.

3. Toxicity occurs with environmental contamination.

4. UL for Adults: 11 mg/day.

5. Toxicity symptoms include nervous system disorders.

C. Manganese Recommendations and Sources

1. Recommendations

a. AI Men: 2.3 mg/day.

b. AI Women: 1.8 mg/day.

2. Sources include nuts, whole grains, leafy vegetables, and tea.

VIII. Fluoride

Fluoride makes bones stronger and teeth more resistant to decay. A deficiency of fluoride increases susceptibility to tooth decay. The use of fluoridated water can reduce dental caries. Excess fluoride causes fluorosis—the pitting and discoloration of teeth.

A. Fluoride Roles in the Body

1. Formation of teeth and bones.

2. Helps to make teeth resistant to decay.

3. Fluorapatite is the stabilized form of bone and tooth crystals.

4. Fluoride and dental caries

a. Widespread health problem.

b. Leads to nutritional problems due to issues with chewing.

B. Fluoride and Toxicity

1. Tooth damage called fluorosis – irreversible pitting and discoloration of the teeth.

2. UL for Adults: 10 mg/day.

3. Prevention of fluorosis

a. Monitor fluoride content of local water supply.

b. Supervise toddlers during tooth brushing.

c. Watch quantity of toothpaste used (pea size) for toddlers.

d. Use fluoride supplements only if prescribed by a physician.

C. Fluoride Recommendations and Sources

1. Recommendations

a. AI Men: 4 mg/day.

b. AI Women: 3 mg/day.

2. Sources include fluoridated drinking water, seafood, and tea.

IX. Chromium

Chromium is an essential nutrient that enhances insulin’s action. It is widely available in unrefined foods. A deficiency of chromium can result in the development of a diabetes-like condition. There are no reported toxicities.

A. Chromium Roles in the Body

1. Enhances insulin action and may improve glucose tolerance.

2. Low chromium levels can result in elevated blood sugar levels.

3. Glucose tolerance factors (GTF) are small organic compounds that enhance insulin’s action and some contain chromium.

B. Chromium Recommendations and Sources

1. Recommendations

a. AI Men: 35 (g/day.

b. AI Women: 25 (g/day.

2. Sources include meat (especially liver), whole grains, and Brewer’s yeast.

C. Chromium Supplements

1. Claims about reducing body fat and improving muscle strength remain controversial.

X. Molybdenum

Molybdenum is a cofactor in several enzymes. It is needed in minuscule amounts. It is available in legumes, grains, and organ meats.

A. Molybdenum functions as a cofactor for several enzymes.

B. No known deficiency symptoms.

C. No reported toxicity symptoms in humans, but has affected animal reproduction.

D. Recommendations

1. Adults: 45 (g/day.

2. UL Adults: 2 mg/day.

E. Food sources include legumes, cereals, and nuts.

XI. Other Trace Minerals

Much of the research on other trace minerals is from animal studies. Humans need very small amounts. Determining exact needs, functions, deficiencies, and toxicities is difficult. Some key roles of these other trace minerals have been identified.

A. Nickel is a cofactor for certain enzymes.

B. Silicon is used in bone and collagen formation.

C. Vanadium is necessary for growth, bone development, and normal reproduction.

D. Cobalt is a key component of vitamin B12.

E. Boron may be key in brain activities.

F. Arsenic may be essential in small quantities.

XII. Contaminant Minerals

Contaminate minerals are also called heavy metals. These include mercury, lead, and cadmium. These minerals enter the food supply through soil, water, and air pollution. They disrupt body processes and impair nutrition status.

A. Lead can have a severe impact on growth and development.

B. Lead interferes with other nutrients.

XIII. Highlight: Phytochemicals and Functional Foods

Phytochemicals are nonnutrient compounds. Only a few of the thousands of phytochemicals have been researched. There are many questions and few answers about their role in human health. Foods that provide health benefits beyond those of nutrients are now called functional foods. Some have an identified role in disease prevention.

A. The phytochemicals give foods taste, aroma, color, and other characteristics.

1. Defending against Cancer

a. Phytoestrogens mimic estrogen

1. Found in soybeans, legumes, flaxseeds, whole grains, fruits, and vegetables.

2. Antioxidant activity.

3. Slow the growth of breast and prostrate cancer.

4. Supplements may stimulate the growth of cancers that depend upon estrogen.

b. Lycopene

1. Powerful antioxidant.

2. May offer some protection against cancer.

3. Found in tomatoes and cooked tomato products, apricots, guava, papaya, pink grapefruits, and watermelon.

c. Five servings of fruits and vegetables are recommended every day.

2. Defending against Heart Disease

a. Flavonoids in foods

1. Powerful antioxidants.

2. Protect against LDL cholesterol oxidation and reduce blood platelet stickiness.

3. Lowers risk of chronic diseases.

4. Found in whole grains, legumes, soy, vegetables, fruits, herbs, spices, teas, chocolate, nuts, olive oil, and red wines.

b. Carotenoids in foods, especially lutein and lycopene

1. Lower risk of heart disease.

2. Found in fruits and vegetables.

c. Phytosterols

1. May protect against heart disease.

2. Inhibit cholesterol absorption.

3. Lower blood pressure.

4. Act as antioxidants.

5. Found in soybeans.

6. Lignans, found in flax seed and whole grains.

3. The Phytochemicals in Perspective

a. Difficult to assess one food and its benefits alone.

b. Actions of phytochemicals are complementary and overlapping.

B. Functional Foods

1. Foods as Pharmacy

a. Margarine enhanced with a phytosterol may lower cholesterol.

b. May be more useful in prevention and mild cases of disease.

c. Drugs are used for severe cases of disease.

2. Unanswered Questions

a. Research is lagging behind food manufacturers.

b. Consumer questions to ask

1. Does it work?

2. How much does it contain?

3. Is it safe?

4. Is it healthy?

C. Future Foods

1. Use of gene research.

2. Can we design foods to meet exact health needs of each individual?

3. Can farmers grow the “perfect” foods?

Case Study

Belinda is a 10-year-old elementary school student who has come in for a physical examination. She is 4 feet 7 inches tall and weighs 120 pounds. Her doctor calculates her BMI at 27.9 (98th% for her age). Concerned about her obesity, Belinda’s doctor asks about her diet and her physical activity. Her mother reports that Belinda has become “lazy” and does not like to play outside with her friends after school. She says she is more irritable than usual and complains about helping with household chores. Her mother worries that she may be depressed, although she can think of no family issues that may be responsible for this behavior. Belinda sometimes skips breakfast or has cereal and toast in the morning; she takes chips, a juice drink, and a cheese sandwich made with white bread for lunch; and has a toaster pastry or cookies with milk for a snack after school. She doesn’t particularly like meat and frequently asks for buttered pasta with cheese for dinner. Belinda says she eats vegetables “when my mom buys them.” A blood test reveals a normal hemoglobin test with a low serum iron, a moderately elevated transferrin level, and a low transferrin saturation.

1. Based on her history, what nutrient deficiencies would you suspect may contribute to Belinda’s symptoms? Explain your answer.

2. What stage of iron deficiency do the results of her laboratory test indicate?

3. What are some meal planning changes that Belinda’s mother could make to improve Belinda’s intake of iron and zinc?

4. What are some lunch and snack ideas that would improve Belinda’s intake of essential elements mentioned in this chapter?

5. If her doctor prescribes an iron supplement, what practical advice would you give Belinda about when and how to take it?

6. What cautions would you give Belinda’s mother regarding excessive supplementation of iron?

Answer Key:

1. Iron: common in growing children and adolescents; symptoms include fatigue, apathy, and irritability, and can appear as behavior problems; often seen in overweight children; usual diet is low in good iron sources; lab results indicate iron deficiency. Zinc: can be seen in growing children, may impair cognition, affects metabolic rate; diet is low in good sources of zinc.

2. Second stage.

3. Buy whole-grain bread and fortified cereals; include a variety of vegetables with meals; prepare meals with meat, chicken, seafood, and legumes.

4. Use whole-grain bread for sandwiches; include dried fruit, beef jerky, peanut butter, nuts, trail mix, tuna, leafy greens such as spinach, and broccoli. Eat beef, chicken, and seafood more often.

5. Take between meals or at bedtime on an empty stomach; take with liquids other than milk, tea, or coffee; a single daily dose is equally effective as multiple daily doses. Vitamin C does not enhance the absorption of iron supplements.

6. Iron toxicity can be life threatening for children. Therefore, keep iron supplements out of reach of children and be especially careful with dosage.

1. Trace minerals have several characteristics in common. Cite four of these common characteristics and discuss them in some detail.

Answer:

1. The quality and the quantity of the trace minerals an individual receives in her/his diet is largely dependent on the soil and water composition in the area in which the individual lives, as well as on how the foods are processed. Prior to our global society, an individual that lived on the east coast would consume differing quantities and qualities of trace minerals than another person on the west coast. This would also be true throughout the world.

2. Trace minerals are active in a number of areas in the body and coordinate with each other to function. Therefore, it is difficult to diagnose a particular trace mineral deficiency. The variability of factors within the body and the diet that can affect each mineral’s bioavailability adds to the difficulty.

3. Trace minerals interact to coordinate each other’s roles or in some cases to counteract each other’s roles. Whatever the case, it is important to understand the connection between the different trace minerals.

4. Only small levels of the trace minerals are needed in the body. In general, the RDA for each mineral is not difficult to achieve with a balanced diet. While toxicity is unusual, given the increasing popularity of vitamin and mineral supplementation, it is plausible that toxicity from trace mineral intake could occur.

2. Given the fast-paced society in which we live and the economic challenges faced by many, individuals tend to make poor food choices or may even go without eating. The consequences of such choices can be nutrient deficiencies with or without physical symptoms and medical consequences. One such symptom is frequent fatigue and one trace mineral deficiency that can result in such symptom presentation is iron. If one of your female classmates complained of constant fatigue, how might you assess her potential for having iron-deficiency anemia? Is there a need to differentiate iron-deficiency anemia from any other type of anemia? If you decided that your classmate did indeed have iron deficiency anemia, what recommendations would you make to her to improve her iron and health status?

Answer: Without having the availability of biochemical testing, assessment should include a dietary assessment, lifestyle assessment, and a medical history/background questionnaire.

1. Medical history: Does the student have any significant medical conditions that one should be aware of, or family members that have a history of iron-deficiency anemia? Has the student recently had surgery, been pregnant, been put on new medications, or been taken off of any regular medications? Is the student taking any medications that may affect iron absorption and metabolism?

Are the student’s menstrual cycles regular? Length of periods? Are her periods heavy, moderate, or light?

Is she an athlete? Does she have any bruising? Has she experienced any recent injuries, if she reports that she is an athlete? Has she taken any falls, etc.?

2. Lifestyle: What is her current academic schedule? Does she also work? What other obligations does she have? Is she presently happy in life and in school? Is she able to get sufficient sleep? (Note: These questions are meant to discern if the student has any underlying depression/psychological disorder that may lead to fatigue. Also, if the student has an extensive schedule to maintain with little time for rest or sleep, this too can result in depression and fatigue.)

3. Dietary: What is the student’s diet? Is she a vegetarian and, if so, what type of vegetarian? Have her fully describe her vegetarian diet. If not, does she eat beef, chicken, pork etc.? How often does she eat fruits and vegetables and what types does she eat?

One can be iron deficient without being anemic. One may also be deficient in copper (while unusual), leading to the anemia. Therefore, it would be important to differentiate the anemia. However, this can really only be done with blood work, which is not available. The student’s written workup does help narrow the possibilities and help the student to direct their colleague for appropriate services.

If it was decided that the student appeared to have an iron-deficiency anemia, the student may have been consuming a diet that was low in iron (most likely from a poorly planned vegetarian diet), experiences a heavy menstrual cycle, is perhaps an athlete, and may even have had some past history of anemia.

In counseling the student, it would be important first to advise her to see her physician or to go to the student health services to be fully evaluated and followed on a regular basis. If she has no other underlying medical conditions, she would benefit from an iron supplement and more careful planning of her vegetarian diet. While it is certainly possible to obtain iron from a vegetarian diet, non-heme iron is less efficiently absorbed as compared to heme iron and the phytates and vegetable proteins in the vegetarian diet also contribute to the reduced absorption rate. Adding vitamin C to her diet in food or supplement form will benefit her iron absorption.

With regard to her athletics and general activities, it would be recommended that she try to maintain a good sleep and rest schedule and avoid unnecessary bruising and trauma. The athlete, in general, does lose more blood in their intestinal tract from breakdown of tissues with their athletic activities that the normal or sedentary individual. This added to her heavy periods has resulted in increased blood losses (iron losses), which are not being made up by her diet (iron intake). Allowing her body to rest does allow the GI tract its own time to heal from the many activities a busy college athlete undertakes.

To instructor: While the student may have many different ideas, it is important for them to think about the variety of factors in a college student’s life that can lead to iron-deficiency anemia, including the need for rest and healing time for the body.

3. Discuss the functions of iodine and selenium. In this discussion, speak about the connections between iodine and selenium regarding some of these functions.

Answer: Iodine is part of the thyroid hormone and is therefore important for metabolism and all components related to metabolism, including reproduction, growth, regulation of body temperature, etc. As one can imagine, iodine deficiency impacts not only the work of the thyroid hormone but also brain function and body growth for the individual (and her fetus, for pregnant females). Selenium is one of several antioxidants in the body. As part of the enzyme glutathione peroxidase, selenium works to prevent free radical formation. Selenium is also part of another enzyme that is important in converting T3 to T4 (activating thyroid hormone).

In most diets, iodine is found in salt that has been iodized. It is also found in seafood, as is selenium. Selenium is also found in other foods and, like most trace minerals, is present at levels correlated to content in the soil.

4. As Highlight 13 points out, while food was once just food, today food can be and is used as a medicine. Discuss some of the pros and cons to this philosophy.

Answer: Pro: It might be argued that food was never just food. If not in the American culture, in other cultures, many types of food, plants, etc. have been used for medicinal purposes. For instance, hot tea with lemon and honey is frequently used to deal with symptoms for a cold or the flu. Molasses and calves’ liver were given to individuals that required more iron; even the discovery that citrus fruits can cure scurvy was essentially using food for pharmacy.

Food in the American culture is really more than just food. Food is comfort; it is culture, religion, pharmacy, healing, and celebration. Every month of the calendar reminds one that food is more than fuel:

January: New Years Day, Super Bowl, Martin Luther King Day, birthdays.

February: Cold weather, Valentine’s Day, school vacations in some areas.

March: Cold weather, sometimes Easter, perhaps start of Passover, college spring breaks.

April: Start of spring, Easter, Passover, some spring breaks, Earth Day.

May: Mother’s day, schools out, outdoor sports start, Memorial Day.

June: Father’s day, schools out, summer starts, pool days, weddings.

July: Fourth of July, camping, vacations.

August: Vacation, beginning school, state and regional fairs.

September: School starts, more fairs, Labor Day, fall starts.

October: Halloween, cold starts, school parties.

November: Thanksgiving, many weather changes.

December: Yom Kipper, Christmas, lots of family, out of school.

Food is a natural substance that can safely provide not only the nutrients we need but also a means of improving health through its healing properties, when combined in a prescriptive manner. Food is not manufactured in a factory nor is it taken as a pill. Food can be enjoyed even when used for its healing properties. When using food as a prescriptive aid, the individual must know a great deal about different healing properties of food or must be connected or working with someone that is reputable and knowledgeable in the area of food and nutrition.

Cons: As noted above, using food as a prescriptive agent can be very complicated and confusing and consumers are advised to seek help in their search to utilize food in such a manner. With continuing research produced daily, the general consumer may have a very difficult time keeping up to date on the latest with each particular category of functional food.

Foods can interact with medications a consumer is taking and further complicate matters. Consumers may think that “it is food, it can’t hurt me”; yet food does interact with medications and there have been reported deaths from drug-nutrient interactions.

Depending on the food source, foods also contain chemicals and drugs that impact and can interact with chemicals within our bodies. Many protein sources are injected with hormones to help them grow more quickly and larger. These hormones have leaked into our food supply, and their total impact is really unknown. Other chemicals such as pesticides also have their own unknown impact.

While organic foods might sound like the answer, without federal regulation, issues with contamination, etc. can be a significant problem. Added to that, organic foods are often more expensive, limiting them to only those that are able to afford them. Often those that most need unprocessed foods are not able to purchase them. Finally, is there a means to help all farmers grow organically on a consistent basis?

While utilizing foods as pharmaceuticals is not the same as using food as a comfort source, the question can be raised regarding the continuing rise in obesity and the need to curb food as the answer to all problems. Food is fuel to the body; however, some Americans believe it is an answer to every problem. If food is utilized as a pharmaceutical, does this propagate more use of food as comfort food?

Functional foods have a bright future; however, there are issues to consider before setting out on a nationwide campaign. These are just a few of the issues to consider.

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