1. The Trace Minerals
Chapter 13

2. The Trace Minerals – An Overview
Food sources
Depend on soil and water composition
Depend on food processing
Deficiencies
Can affect people of all ages
May be difficult to recognize
Toxicities
FDA regulation of supplements

3. The Trace Minerals – An Overview
Interactions
Common and well coordinated to meet needs
May lead to nutrient imbalances
Excess in one may cause a deficiency of another
Interfere with work of minerals
Contaminant minerals causing toxic reactions
Research of trace minerals is active, suggesting there is more to learn.

4. Iron Too little and too much can be harmful Roles in the body
Switches back and forth between two forms
Ferrous iron (reduced state)
Ferric iron(oxidized state)
Cofactor in oxidation-reduction reactions
Widespread in metab; enzymes making aa, collagen, hormones, & neurotransmitters
Part of electron carriers
Form water & produce ATP
Hemoglobin and myoglobin
2 proteins found in RBC & muscle cells

5. Iron (Fe) Absorption Body conserves iron Ferritin
Balance maintained primarily through absorption
Ferritin
Iron-storage in small intestine
When Fe is needed ferritin releases some Fe to an Fe support protein called
Transferrin
Iron transport protein

6. Iron Absorption

7. Iron Absorption Absorption-enhancing factors Dietary sources
Heme iron (animals)
Nonheme iron (plant & animal)
Absorption-enhancing factors
MFP factor
Peptide that promotes absorption of nonheme Fe from other foods eaten at same meal
Vitamin C
Some acids and sugars

8. Heme and Nonheme Iron in Foods

9. Iron Absorption-inhibiting factors
Phytates
Vegetable proteins
Calcium
Polyphenols
Dietary factors combined; MFP & vit C as enhancers & phytates as inhibitors
Individual variation in absorption
Health, stage in life cycle, and iron status

10. Iron Iron Transport and Storage Iron Recycling Iron Balance
Surplus is stored in bone marrow, spleen, and liver.
Hemosiderin is a storage protein used when concentrations of iron are extremely high.
Storing excess iron is a protective measure because iron can act as a free radical.
Iron Recycling
The liver and spleen dismantle red blood cells and package iron into transferrin.
Transferrin carries iron in the blood.
Bone marrow incorporates iron into hemoglobin and stores iron as ferritin.
Iron-containing hemoglobin carries oxygen in the blood.
Iron is lost when bleeding occurs and through the GI tract.
Iron Balance
The absorption, transport, storage, recycling, and loss of iron must be regulated in order to maintain iron balance.
Hepcidin is a hormone that inhibits the absorption and transport of iron to keep blood levels within normal ranges.

11. Iron Deficiency Most common nutrient deficiency worldwide
Populations affected in U.S.
10% toddlers, adolescent girls, and women of childbearing age
Link with being overweight
Vulnerable stages in life
Women in reproductive years
Pregnancy
Infants and young children
Adolescence

12. Iron Deficiency Assessment of deficiency Blood losses
Deficiency develops in stages
Iron stores diminish – serum ferritin
Decrease in transport iron – transferrin
Iron deficiency – hemoglobin and hematocrit values

13. Iron Iron deficiency and anemia
Deficiency – depleted iron stores without regard to degree of depletion
Anemia – severe depletion of iron stores
Low hemoglobin concentrations
Pale & small RBCs (hypochromic, microcytic)

14. Iron Deficiency and behavior Pica Energy metabolism is impaired
Neurotransmitter synthesis is altered
Reduces work capacity and mental productivity
Motivational problems
Pica
Craving and consumption of nonfood substances

15. Iron Toxicity Hereditary hemochromatosis
(Most common genetic disorder in U.S.)
Genetic failure to prevent unneeded iron in the diet from being absorbed
Hormone hepicidin supports homeostasis and absence/ineffectiveness causes hemochromatosis
Hemosiderosis
Deposits of iron-storage pro hemosiderin in liver, heart, joints, and other tissues

16. Iron Symptoms of iron overload include: Treated with chelation therapy
infections, fatigue, joint pain, skin pigmentation, and organ damage.
Problems include liver tissue damage and infections.
Higher risk of diabetes, liver cancer, heart disease, and arthritis.
More common in men then in women.
Treated with chelation therapy
Use of EDTA to bind with metallic ions, thus healing the body by removing toxic metals

17. Iron Heart disease Cancer Iron poisoning Excess iron
Free radicals
Cancer
Free-radical damage
Iron poisoning
Symptoms of toxicity UL

18. Iron Iron and Heart Disease Iron and Cancer Iron Poisoning
may be a link to high iron stores.
Iron and Cancer
may be a link with free radical activity resulting in damage to DNA.
Iron Poisoning
UL for adults: 45 mg/day.
Accidental supplement poisoning in children.
Symptoms include nausea, vomiting, diarrhea, rapid heartbeat, weak pulse, dizziness, shock, and confusion.

19. Iron Recommendations and sources Maximizing absorption
Select iron-rich foods
Natural – meats, fish, poultry, legumes, eggs
Enriched – flour and grain products
RDAs
RDA Men: 8 mg/day for adults years of age.
RDA Women: 18 mg/day for adults years of age.
RDA Women: 8 mg/day for adults over 51 years of age.
Vegetarians need 1.8 times as much iron because of low bioavailability.
Maximizing absorption
Bioavailability is
high in meats, fish, and poultry.
intermediate in grains and legumes.
low in vegetables.
Combined effect of enhancing and inhibiting factors.

20. Iron Contamination & supplementation Iron cookware Supplements
Iron content of foods
Supplements
Groups that may need supplements
Enhancing absorption
Vitamin C
Physician prescription

21. Zinc
Roles in body
Gene expression
Cell membranes
Immune function
Growth & development
Synthesis, storage, and release of insulin
Blood clotting
Thyroid hormone function
Behavior & learning performance
Visual pigment
Taste perception
Sperm production
Zn def impairs all these and other functions, underlining the vast importance of Zn in supporting the body’s proteins.

22. Zinc Absorption Upon absorption Recycling Zinc losses
Rate varies depending on zinc status
Dietary factors
Upon absorption
Zn can participate in metabolic function of intestinal cells itself or may be retained with the intestinal cells by metallothionein until the body needs Zn
Recycling
Small intestine
Two doses of zinc (food/meals & Zn-rich pancreatic secretions)
Enteropancreatic circulation
travels from the pancreas to the intestines and back.
Zinc losses
occur in the feces, urine, shedding of skin, hair, sweat, menstrual fluids, and semen.

23. Zinc Transport Zinc Deficiency Symptoms of deficiency:
Transported by the protein albumin.
Binds to transferrin.
Excessive iron and copper can lead to a zinc deficiency and excessive zinc can lead to an iron and copper deficiency
Zinc Deficiency
Not widespread.
Occurs in pregnant women, young children, the elderly, and the poor.
Symptoms of deficiency:
Growth retardation
Delayed sexual maturation.
Impaired immune function.
Hair loss, eye and skin lesions.
Altered taste, loss of appetite, and delayed wound healing.

24. Zinc Zinc Recommendations and Sources RDA Men: 11 mg/day.
Zinc Toxicity
UL for Adults: 40 mg/day.
Symptoms
Loss of appetite.
Impaired immunity.
Low HDL.
Copper and iron deficiencies.
Vomiting and diarrhea.
Exhaustion.
Headaches.
Zinc Recommendations and Sources
RDA Men: 11 mg/day.
RDA Women: 8 mg/day.

25. Zinc
Zinc in foods
Protein-containing foods such as shellfish, meats, poultry, milk, and cheese.
Whole grains, legumes, and some fortified cereals.
Zinc Supplementation
Developing countries use zinc to reduce incidence of death associated with diarrhea.
Zinc lozenges for the common cold are controversial and inconclusive.

26. Iodine GI tract converts iodine to iodide Roles in the body
Iodine – in food
Iodide – in body
Roles in the body
Part of thyroid hormones
Body temperature, metabolic rate, reproduction, growth, blood cell production, nerve and muscle function, etc.

27. Iodine Deficiency Thyroid hormone production declines
Greater secretion of thyroid-stimulating hormone (TSH)
Goiter
Enlarged thyroid
Most common cause of preventable mental retardation and brain damage
Cretinism-severe def during pregnancy; irreversible

28. Iodine Toxicity Recommendations Sources
Interferes with thyroid function
Enlarges thyroid gland
Goiter in an infant UL
Adult: 1100 micrograms/day
Recommendations
Sources

29. Selenium Substitute for sulfur in some amino acids Roles in body
Methionine, cysteine, and cystine
Roles in body
Antioxidant
Part of proteins
Glutathione peroxidase; works with vit E
Prevents free-rad formation
Conversion of thyroid hormone to active form

30. Selenium Deficiency Cancer Toxicity Heart disease
May be protective factor
Foods vs. supplements
Toxicity
UL: 400micrograms/day
Effects

31. Selenium Sources Recommendations Found in soil Meats, milk, and eggs
Brazil nuts
Recommendations
RDA: 55µg/day

32. Copper Transport and balance depend on a system of proteins
Roles in body
Constituent of enzymes
Reactions that consume oxygen or oxygen radicals
Iron metabolism
Defense against oxidative damage
Other roles

33. Copper Deficiency Recommendations – Adults: 900 g/day. Sources
Deficiency is rare in the U.S.; however, symptoms include anemia and bone abnormalities.
In Menkes disease, copper cannot be released into the circulation.
Recommendations – Adults: 900 g/day.
Sources
Seafood, nuts, seeds, and legumes.
Whole grains.
In houses with copper plumbing, water can be a source.
Toxicity
Excessive intakes
Foods vs. supplements
Genetic disorders
Menkes disease
Wilson’s disease
Major route of elimination appears to be bile

34. Manganese Body locations Roles in body Bones
Metabolically active organs
Roles in body
Cofactor for enzymes that facilitate metabolism
Bone formation
Conversion of pyruvate to a TCA cycle compound

35. Manganese Deficiency Toxicity Manganese Recommendations and Sources
Deficiency symptoms are rare.
Phytates, calcium, and iron limit absorption.
Toxicity
Toxicity occurs with environmental contamination.
UL for Adults: 11 mg/day.
Toxicity symptoms include nervous system disorders.
Manganese Recommendations and Sources
Recommendations
AI Men: 2.3 mg/day.
AI Women: 1.8 mg/day.
Sources include nuts, whole grains, leafy vegetables, and tea.

36. Fluoride Roles in the Body Fluoride and dental caries Toxicity
Formation of teeth and bones.
Helps to make teeth resistant to decay.
Fluorapatite is the stabilized form of bone and tooth crystals.
Fluoride and dental caries
Widespread health problem.
Leads to nutritional problems due to issues with chewing.
Toxicity
Tooth damage called fluorosis – irreversible pitting and discoloration of the teeth.
UL for Adults: 10 mg/day.

37. Fluoride Prevention of fluorosis Recommendations
Monitor fluoride content of local water supply.
Supervise toddlers during tooth brushing.
Watch quantity of toothpaste used (pea size) for toddlers.
Use fluoride supplements only if prescribed by a physician.
Recommendations
AI Men: 4 mg/day.
AI Women: 3 mg/day.
Sources include fluoridated drinking water, seafood, and tea.

38. Chromium Roles in the body Sources Supplements
Participates in carbohydrate and lipid metabolism
Helps maintain glucose homeostasis
Diabetes-like condition
Sources
Refined foods
Supplements

39. Chromium Roles in the Body Recommendations
Enhances insulin action and may improve glucose tolerance.
Low chromium levels can result in elevated blood sugar levels.
Glucose tolerance factors (GTF) are small organic compounds that enhance insulin’s action and some contain chromium.
Recommendations
AI Men: 35 g/day.
AI Women: 25 g/day.
Sources include meat (especially liver), whole grains, and Brewer’s yeast.
Supplements
Claims about reducing body fat and improving muscle strength remain controversial.

40. Closing Thoughts on the Nutrients
Look at nutrients as a whole
Work cooperatively with one another
Actions are most often interactions
Most foods deliver multiple nutrients
Needs are based on the support of optimal health
Nutrients are being examined in context of whole diet