The Trace MineralsThe Trace Minerals

Trace MineralsTrace Minerals

Iron, Zinc, Iodine, Selenium, Copper, Iron, Zinc, Iodine, Selenium, Copper, Manganese, Fluoride, Chromium, Manganese, Fluoride, Chromium, MolybdenumMolybdenum

Needed in minute quantitiesNeeded in minute quantities Toxicity may occur at intakes not far above Toxicity may occur at intakes not far above

estimated requirementestimated requirement Found in a variety of foodsFound in a variety of foods

IronIron

General informationGeneral information Most of the body’s iron is in hemoglobin and Most of the body’s iron is in hemoglobin and

myoglobinmyoglobin Carries oxygen for use in energy metabolismCarries oxygen for use in energy metabolism Proteins assist with iron absorption, transport, Proteins assist with iron absorption, transport,

and storageand storage

Iron - RDAIron - RDA

MenMen 8 mg/day8 mg/day

WomenWomen 18 mg/day (19-50 yrs); 8 mg/d (51 +)18 mg/day (19-50 yrs); 8 mg/d (51 +)

Upper Level: Adults: 45 mUpper Level: Adults: 45 mg/dayg/day

Iron - Major FunctionsIron - Major Functions

Carries oxygenCarries oxygen Co-factor to enzymes involved in oxidation-Co-factor to enzymes involved in oxidation-

reduction reactionsreduction reactions Part of electron carriers in electron transport Part of electron carriers in electron transport

chainchain

Slide 6

Figure 13-3Page 441

Iron Recycled in the Body

Iron-containinghemoglobin in redblood cellscarries oxygen.

Transferrin carriesiron in blood.

Some irondelivered tomyoglobinof muscle cells

Some lossesif bleedingoccurs

Bone marrow incorporatesiron into hemoglobin ofred blood cells and storesexcess iron in ferritin(and hemosiderin).

Liver (and spleen) dismantlesred blood cells, packagesiron into transferrin, andstores excess iron inferritin (and hemosiderin).

Some lossesvia sweat, skin,and urine

Iron - DeficiencyIron - Deficiency

Worldwide, most common nutrient deficiency, Worldwide, most common nutrient deficiency, affects > 1 billion peopleaffects > 1 billion people

High risk: women in reproductive years, pregnant High risk: women in reproductive years, pregnant women, infants & young children, teenagerswomen, infants & young children, teenagers

Blood loss may also lead to iron deficiencyBlood loss may also lead to iron deficiency Develops in stagesDevelops in stages Iron-deficiency anemiaIron-deficiency anemia severe depletion iron severe depletion iron

storesstores

Slide 8

Figure 13-4Page 443

Normal and Anemic Blood Cells

Blood cells in iron-deficiency anemia aresmall (microcytic) and pale (hypochromic)because they contain less hemoglobin.

Both size and color are normal in theseblood cells.

Slide 9

Table 13-1Page 458

Iron - ToxicityIron - Toxicity

Toxicity from excess iron results in iron Toxicity from excess iron results in iron overloadoverload

More common in menMore common in men Iron-containing supplements leading cause Iron-containing supplements leading cause

of accidental poisoning in childrenof accidental poisoning in children

Major Food SourcesMajor Food Sources

Red meats, fish, poultry Red meats, fish, poultry sources of heme sources of heme iron & contain MFP factor, which enhance iron & contain MFP factor, which enhance iron absorption; shellfish, eggsiron absorption; shellfish, eggs

Non-heme sources of iron include legumes, Non-heme sources of iron include legumes, iron-enriched grainsiron-enriched grains

Non-heme iron absorption increased with Non-heme iron absorption increased with MFP foods, Vitamin C MFP foods, Vitamin C

Slide 12

Figure 13-2Page 440

Heme and Nonheme Iron in Foods

All the iron in foodsderived from plantsis nonheme iron.

Only foods derived fromanimal flesh provideheme, but they alsocontain nonheme iron.

Heme accounts for about10% of the average dailyiron intake, but it is wellabsorbed (about 25%).Nonheme iron accountsfor the remaining 90% butit is less well absorbed(about 17%).

Heme

Key:

Nonheme

Slide 13

In-text Figure Page 445

When the label on a grainproduct says “enriched,”It means iron and severalB vitamins have beenadded.

Slide 14

In-text Figure Page 447An old-fashioned iron skillet adds iron to foods.

ZincZinc

General informationGeneral information Required as a cofactor by more than 100 Required as a cofactor by more than 100

enzymes; all cells contain zincenzymes; all cells contain zinc RDA – Men: 11 mg/d; Women: 8 mg/dRDA – Men: 11 mg/d; Women: 8 mg/d Upper level: Adults - 40 mg/d Upper level: Adults - 40 mg/d

Zinc - Major FunctionsZinc - Major Functions

Part of many enzymesPart of many enzymes Involved in making genetic material and Involved in making genetic material and

proteinsproteins Involved in immune reactionsInvolved in immune reactions Transport of Vitamin ATransport of Vitamin A Taste perceptionTaste perception

Zinc - DeficiencyZinc - Deficiency

Severe growth retardationSevere growth retardation Hinders digestion & absorption, causing Hinders digestion & absorption, causing

diarrheadiarrhea Impairs immune functionImpairs immune function Alters taste, causes anorexia, slows wound Alters taste, causes anorexia, slows wound

healinghealing

Slide 18

Figure 13-7Page 449

Zinc-Deficiency Symptoms—The Stunted Growth of Dwarfism

The boy on the left is 17 yearsold but is only4 feet tall.

The man on the right is an adult of average height.

Zinc - ToxicityZinc - Toxicity

Vomiting, diarrhea, headaches, other Vomiting, diarrhea, headaches, other symptomssymptoms

Zinc-Food SourcesZinc-Food Sources

Protein-containing foods: meats, fish, Protein-containing foods: meats, fish, poultry, poultry, whole grains, vegetableswhole grains, vegetables

Slide 21

In-text Figure Page 449

Zinc is highest in protein-richfoods such as oysters, beef,poultry, legumes, and nuts.

IodineIodine

General informationGeneral information Part of thyroid hormone that regulates body Part of thyroid hormone that regulates body

temperature, metabolic rate, reproduction, temperature, metabolic rate, reproduction, growth, and moregrowth, and more

RDA - 2001RDA - 2001 Adults: 150 Adults: 150 µµg/dayg/day Upper level: 1.1 mg/dayUpper level: 1.1 mg/day

Iodine - DeficiencyIodine - Deficiency

Simple goiter; cretinismSimple goiter; cretinism Enlargement of thyroid gland, weight gainEnlargement of thyroid gland, weight gain

Iodine - ToxicityIodine - Toxicity

Enlargement of thyroid glandEnlargement of thyroid gland Especially damaging to developing fetusEspecially damaging to developing fetus Upper limit: 1000 Upper limit: 1000 µµg/dayg/day

Iodine - Food SourcesIodine - Food Sources

Ocean is world’s major source of iodineOcean is world’s major source of iodine Iodized salt,Iodized salt, seafood, bread, dairy products, seafood, bread, dairy products,

plants grown in iodine-rich soilplants grown in iodine-rich soil

Slide 26

In-text Figure Page 452Only “iodized salt” has had iodine added.

Selenium, Copper, ManganeseSelenium, Copper, Manganese

SeleniumSelenium – Antioxidant, works with Vitamin E; – Antioxidant, works with Vitamin E; deficiency associated with a heart disease; food deficiency associated with a heart disease; food sources – seafood, meat, whole grainssources – seafood, meat, whole grains

CopperCopper – Part of several enzymes, necessary for – Part of several enzymes, necessary for absorption & use of iron; deficiency is rare; food absorption & use of iron; deficiency is rare; food sources – legumes, whole grains, nuts, shellfishsources – legumes, whole grains, nuts, shellfish

ManganeseManganese – Involved in various metabolic – Involved in various metabolic processes; deficiencies rare; food sources – nuts, processes; deficiencies rare; food sources – nuts, whole grains, leafy veggieswhole grains, leafy veggies

FluorideFluoride

Major Functions: Makes bones stronger, Major Functions: Makes bones stronger, teeth resistant to decayteeth resistant to decay

Food Sources: Fluoridated water, tea, foods Food Sources: Fluoridated water, tea, foods prepared with fluoridated water, seafoodprepared with fluoridated water, seafood

Toxicity: Fluorosis (mottling of teeth)Toxicity: Fluorosis (mottling of teeth)

Slide 29

Figure 13-10Page 456

U.S. Population with Access to Fluoridated Water through Public Water Systems

Key:

< 49%

50% – 74%

> 75%

Chromium, MolybdenumChromium, Molybdenum

ChromiumChromium – Participates in carbohydrate – Participates in carbohydrate and lipid metabolism; present in a variety of and lipid metabolism; present in a variety of foodsfoods

MolybdenumMolybdenum – Cofactor for several – Cofactor for several enzymes; unknown deficiency; found in enzymes; unknown deficiency; found in legumes, cereals, organ meatslegumes, cereals, organ meats

Slide 31

Figure 13-1Page 439

Iron Absorption

If the bodyneeds iron

Iron is excreted inshed intestinal cells.

If the bodydoes notneed ironMucosal cells in the

intestine store excessiron in mucosal ferritin(a storage protein).

Iron in food

Mucosal ferritin releases iron tomucosal transferrin (a transportprotein), which hands off iron toanother transferrin that travelsthrough the blood to the rest ofthe body.

Slide 32

In-text Figure Page 441

This chili dinner provides several factors that may enhance ironabsorption: heme and non-heme iron and MFP from meat, nonheme

iron from legumes, and vitamin C from tomatoes.

Slide 33

Figure 13-5Page 446

Iron in Selected Foods

Key:

Fruits

Milk and milk products

Legumes, nuts, seeds

Meats

Best sources per kcalorie

Breads and cereals

Vegetables

IRONMeats (red), legumes (brown),and some vegetables (green)make the greatest contributionsof iron to the diet.

RDA forwomen

51+

RDA forwomen19–50

RDAfor

men

Slide 34

Figure 13-6Page 448

Enteropancreatic Circulation of Zinc

If the bodyneeds zinc

Zinc in food

The pancreas useszinc to makedigestive enzymesand secretes theminto the intestine.

Zinc is excreted inshed intestinal cells.

Metallothionein releaseszinc to albumin andtransferrin for transportto the rest of the body.

If the bodydoes notneed zinc

Mucosal cells inthe intestine storeexcess zinc inmetallothionein.

Slide 35

Figure 13-8Page 450

Zinc in Selected Foods

Label

Key:

Fruits

Milk and milk products

Legumes, nuts, seeds

Meats

Best sources per kcalorie

Breads and cereals

Vegetables

ZINCMeat, fish, and poultry (red) areconcentrated sources of zinc.Milk (white) and legumes(brown) contain some zinc.

RDAfor

women

RDAfor

men

Micrograms RAEFood Serving size (kcalories)

Slide 36

Figure 13-12Page 458

Cobalt with Vitamin B 12

The intricate vitamin B12 moleculecontains one atom of the mineralcobalt. The alternative name forvitamin B12 , cobalamin, reflectsthe presence of cobalt in itsstructure.

Slide 37

Click to view animation.

Practice planning meals with varying energy needs to meet recommended intakes of several minerals.

Animation

Slide 38

In-text Figure Page 465

Phytochemicals and Functional Foods

Slide 39

Table H13-1Page 466

Slide 40

Table H13-1(2)Page 466

(cont.)

Slide 41

In-text Figure Page 467Nature offers a variety of functional foods that

provide us with many health benefits.

Slide 42

Fig. H13-1 (1)Page 468

An Array of Phytochemicals in a Variety of Fruits and Vegetables

The phytochemical resveratrol found in grapes (and nuts)protects against cancer by inhibiting cell growth and againstheart disease by limiting clot formation and inflammation.

The flavonoids in cocoa and chocolate defendagainst oxidation and reduce the tendency ofblood to clot.

Broccoli and broccoli sprouts contain an abundance of thecancer-fighting phytochemical sulforaphane.

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Fig. H13-1 (2)Page 468

An Array of Phytochemicals in a Variety of Fruits and Vegetables (cont’d)

Tomatoes, with their abundant lycopene, may defend against cancer by protecting DNA from oxidative damage.

The ellagic acid of strawberries may inhibit certain types ofcancer.

An apple a day—rich in flavonoids—may protect against lung cancer.

Spinach and other colorful vegetables containthe carotenoids lutein and zeaxanthin, whichhelp protect the eyes against maculardegeneration.

Slide 44

Fig. H13-1 (3)Page 468

An Array of Phytochemicals in a Variety of Fruits and Vegetables (cont’d)

The monoterpenes of citrus fruits (and cherries) mayinhibit cancer growth.

Flaxseed, the richest source of lignans,may prevent the spread of cancer.

The phytoestrogens of soybeans seem to starve cancercells and inhibit tumor growth; the phytosterols maylower blood cholesterol and protect cardiac arteries.

Slide 45

Fig. H13-1 (4)Page 468

An Array of Phytochemicals in a Variety of Fruits and Vegetables (cont’d)

The flavonoids in black tea may protect against heart disease, whereas those in green tea may defend against cancer.

Blueberries, a rich source of flavonoids,improve memory in animals.

Garlic, with its abundant organosulfur compounds, may lower blood cholesterol and protect against stomachcancer.

Slide 46

In-text Figure Page 469

Functional foods currently on the market promise to “enhance mood,”“promote relaxation and good karma,” “increase alertness,” and

“improve memory,” among other claims.