Chapter 13

The Trace Minerals

Trace Minerals/Microminerals

Essential mineral nutrients found in the human body in amounts less than 5 grams.

Best food sources are unprocessed, whole foods.

Severe deficiencies are easily recognized but mild deficiencies are easily overlooked.

Easy to reach toxic levels of trace minerals. Trace minerals interactions are common.

The Trace Minerals

IronZincIodineSeleniumCopper

ManganeseFluorideChromiumMolybdenum

IronEssential nutrientVital to many cells’ activities.Too much or too little is

harmful.

Iron Roles- most of the body’s iron is in 2

proteins – hemoglobin and myoglobin Hemoglobin – oxygen carrying protein in the

red blood cells- 80% of the body’s iron Myoglobin – oxygen- holding protein of the

muscle cells. Iron absorption- iron is held temporarily in

intestinal cells. When iron is needed it is made available and when there is an excess it is excreted with the intestinal cells. – About every 3 days.

Iron Heme Iron – found only in food from

flesh of animals. Non Heme Iron – some in animal

sources but all of iron from plant source.

MFP factor – meat, fish, and poultry – promotes the absorption of non heme iron from other foods at the same meal.

Iron Phytates and fibers; oxalates;

Calcium and Phosphorus; EDTA; tannic acids – inhibit absorption of non heme iron.

Vitamin C and MFP as enhancers Phytates as inhibitors 18 % of dietary iron is absorbed.

Iron Iron is transported to bone marrow where a

large amount is used to make new red blood cells.

Surplus iron is stored in ferritin- in the liver, bone marrow and spleen.

Average RBC lives 4 months- then broken down and recycled. Iron is attached to blood transferrin, carried back to bone marrow to make new RBC’s

Iron Some iron is lost daily in the GI tract and

in blood if bleeding occurs. Very small is lost in feces, urine, sweat,

and skin.

Iron Deficiency The state of having depleted iron stores. The most common nutrient deficiency. Increased risk of females in reproductive

years; pregnant women; infants and children; teenagers.

Stages of iron deficiency Iron stores diminish Transport iron decreases Hemoglobin production declines

Iron Deficiency Iron deficiency anemia – severe depletion

of iron stores that results in low hemoglobin and small, pale, red blood cells. Is a microcytic hypochromic anemia- Micro=small, cytic=cells, hypo=too little,

chrom=color

Iron Pica – a craving for non food

substances seen in some iron deficient people.

Geophagia – eating clay or dirt Geo=earth phagein=to eat Pagophagia – eating ice Pago=frost phagein= to eat

Iron Toxicity Not common – the body absorbs less

when the stores are full. Hemochromatosis – iron overload, genetic

defect in iron metabolism – deposits iron containing pigments in tissue, causing damage.

Hemosiderosis – condition characterized by depositing hemosiderin(slow releasing iron storage protein) in the liver and other tissues.

Recommendation High iron intake is believed to be related to

increased heart disease and cancer. Men/51+ - 8 mg/day Child bearing- 18 mg/day, receive

12-13mg/day 8 mg of canned clams are best source per

Kcalorie Contamination iron – iron from non-food

sources- iron cookware and iron containing soil.

Zinc Required as a cofactor by 100+

enzymes Highest concentrations in muscle

and bone Eat zinc-rich foods frequently

Zinc Roles Support work of proteins including

metalloenzymes Metalloenzymes- enzymes that contain one or

more minerals as part of their structure. Stabilizes cell membranes to fight free radicals Assist in immune function, growth, and

development Participates in making, storing, and releasing

insulin

Zinc Absorption 15-40%- depending on person’s

status Enteropancreatic circulation-The

route zinc takes in the body from the pancreas to the intestine and back to the pancreas.

Zinc Transport Main vehicle in the blood is the

protein albumin and determines zinc absorption

Interactions with iron and copper High zincLower copper absorption High ironLower zinc absorption Most zinc lost in feces

Deficiency, Toxicity, Recommendations, & Sources

Def. Symptoms- growth retardation, abnormal collagen sources, synthesis, lost of taste, poor wound healing

Toxic symptoms- high doses vomiting, diarrhea, headaches and exhaustion

Rec.-men (11 mg/day) women (8 mg/day)

Sources: Protein foods, shellfish (oysters), whole grains, vegies

Iodine Iodine ion is iodide and vital to life Thyroid hormone – regulates body

temp., metabolic rate, reproduction growth…

Deficiency/Toxicity Simple goiter- enlargement of the

thyroid gland due to iodine deficiency Cretinism – congenital diseases

caused by iodine deficiency during pregnancy

Excessive iodine intakes can enlarge the thyroid

Sources, Intake, Recommendations

Costal areas, seafood, dairy products, bread, iodized salt

2001 RDA – Adults: 150 micrograms/day

Upper level – 11 mg/day

Selenium One of the body’s antioxidant

nutrients Selenium – poor soil in some parts of

the world are believed to increase risk of some cancers

Receive selenium from foods we eat that are grown in selenium rich soil

Deficiency/Toxicity Deficiency In China- heart disease

where the cardiac tissue becomes fibrous.

Toxic- High doses causes vomiting, diarrhea, loss of hair and nails, and skin and nervous system lesions.

Copper 100 mgs in the body – found in several

cells and tissues Important in hemoglobin synthesis Participates in the body’s natural defense

against free radicals (as antioxidants) Helps manufacture collagen, and heal

wounds

Deficiency/Toxicity Deficiency rare but noted in premature

infants and malnourished children Vitamin C can interfere with absorption

and lead to deficiency US adequate intake – but not toxic Wilson’s disease-accumulates in the liver

and brain – life-threatening toxicity

Recommendations/Sources

2001 RDA – Adults 900 micrograms/day

Upper level – Adults 10 mg/day Sources: legumes, whole grains,

nuts, shellfish, organ meats, and seeds

Eliminate by bile

Manganese 20 mg in body – in bones, liver, kidneys,

and pancreas Involved in metabolic processes 2001 Adequate Intake: Men (2.3 mg/day)

Women (1.8 mg/day) Upper Level Adults – (11 mg/day)

Deficiency, Toxicity, Sources

Deficiencies are rare Dietary phytates inhibit its absorption Increased iron and decreased calcium for

manganese absorption Toxic from environmental condition

instead of dietary

Fluoride In soils, water, plants, and animals Mineralization of bones and teeth,

hydroxapatite occurs and then fluoride replaces the hydroxyl part and forms fluorapatite

Helps prevent dental caries Fluorosis- excess fluoride during tooth

formation – dark and pitting in tooth enamel

Toxicity, Intakes Toxic when public water systems malfunction

and allowed massive fluoride Symptoms- nausea, vomiting, diarrhea,

abdominal pain, and numbness in face and extremities

In fish and teas as well as water 1997 Adequate Intake: Men (3.8 mg/day)

Women (3.0 mg/day) Upper Levels: Adults (10 mg/day)

Chromium Essential mineral participate in carbohydrate

and lipid metabolism Helps maintain glucose homeostasis by

enhancing the activity of the hormone insulin In a variety of foods – best unrefined foods-

liver, yeast, whole grains, nuts and cheeses Controversial whether chromium supplements

help body fat and increase muscle strength 2001 Adequate Intake: Men (35

micrograms/day) Women (25 micrograms/day)

Molybdenum Tiny amounts needed In legumes, breads, and grain products,

green leafy vegetables, milk and liver Rare- toxicity – but would cause kidney

damage and reproductive abnormalities 2001 RDA Adults: 45 micrograms/day Upper level Adults: 2 mg/day

STUDY HARD!

Good Luck on your Test!