Nutrition 322.13 Ppt
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Transcript of Nutrition 322.13 Ppt
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!