3. Lectures.minerals & Trace Elements
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Transcript of 3. Lectures.minerals & Trace Elements
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8/12/2019 3. Lectures.minerals & Trace Elements
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Mineral Classification
Macrominerals Microminerals
Calcium IronPhosphorus Zinc
Magnesium Copper
Sulfur Selenium
Sodium ChromiumPotassium Iodine
Chloride Fluoride
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Calcium
Structure: in foods as inorganic salts (carbonates, phosphates andsilicates), complexes with oxalated, phytates and proteins
Food Sources:
Milk and milk products, legumes, canned fish (including bones)
Functions:
Hardening of bones and teeth
Nerve functioning
Muscle contraction
RDI: 800 mg/day for men and 1000 mg/day for women
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Calcium
Deficiency:
Rickets
Osteoporosis
Therapeutic Effects:
May reduce hypertension
May play a role in weight reduction
Toxicity:None
Plasma levels tightly regulated
Kidney stones??
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Magnesium
Structure: complexes with proteins, chlorophyll etc
Food Sources:
Whole grains (wheat bran), broccoli, squash, beans, nuts, seeds
Hard tap water
Functions:
Key component of enzymes
Cell membranes & bone crystal
RDI: 270 mg for females, 300 mg for males, additional 30 mg during
pregnancy and 70 mg/day during lactation
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Magnesium
Deficiency:
Rare
Use of thiazide diuretics may increase urinary excretion
Therapeutic Effects:
None well established
Back or shoulder or other muscular pain
Toxicity:
None in healthy humans who eats natural foods
May reduce calcium absorption
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Iron
2+
Ferric (Fe3+)
&
Ferrous (Fe2+)
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Iron
Structure:
Heme or non-heme iron
Food Sources:
Meat, fish (clams and oysters) & poultry
Dark green leafy vegetables, breakfast cereals, egg yolk, black strap
molasses, nuts, seeds & dried fruits
Milk is a poor source of iron
Functions:
Oxygen transport
Synthesis of collagen
Synthesis of neurotransmitters (dopamine, epinephrine, norepinephrineand serotonin)
RDI: 9 mg/day for 7-12 month infants; 6-8 mg for up to 7 years
10-13 mg/day for males, 12-16 mg/day for females; 22-36 mg/dayduring pregnancy; 7 mg/day for postmenopausal women
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Iron
Deficiency:
Iron Deficiency Anaemia
Therapeutic Effects:
None
Toxicity:
Hemochromatosis
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Zinc
Structure: in foods as inorganic salts and complexes with proteins
Food Sources:
Oysters, wheat germ, beef, calf liver, dark meat of turkey and chicken andwhole grains, particularly wheat
Functions:
Key component of enzymes
Protein synthesis
Collagen formation
Alcohol detoxification
Carbon dioxide elimination
Sexual maturation
Taste and smell functions
RDI: 3 mg for infants, 12 mg for adults and additional 4 mg/day duringpregnancy and lactation respectively
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Zinc
Deficiency:
Poor wound healing, subnormal growth, anorexia, abnormal
taste and smell, changes in hair, nails, skin inflammation,
anaemia, retarded development of the reproductive system
Therapeutic Effects:
None
Toxicity:
May impair copper absorption - metallothionine
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Copper
Structure: complexes with proteins
Food Sources:
Liver, kidney, shellfish, whole grains, cherries, legumes, chocolate,
nuts, eggs, muscle meats, fish and poultry
Functions:
Required for proper use of iron by the body (ceruloplasmin)
Role in development of connective tissue, blood vessels
Synthesis of neurotransmitters (noradrenaline)
Cuproenzymes (oxidases)
RDI: No RDI in Australia; 1.0-1.5 mg/day is considered adequate
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Copper
Deficiency:
Anaemia, neutropenia, leukopenia, bone
demineralisation and failure of erythropoiesis
Therapeutic Effects:None
Toxicity:
None in healthy humans who eats natural foods
May reduce zinc absorption
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Selenium
Structure:
Selenoproteins
Sodium selenite
Food Sources:
Grains, meat, poultry, fish and dairy products
Functions:
Works with glutathione peroxidase to protect cells againstdestruction by hydrogen peroxide
Spare vitamin E
RDI: 70 g for females; 85 g for males; additional 5-10 g duringpregnancy and lactation
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Selenium
Deficiency:
Myalgia, cardiac myopathy (Keshans Disease)
Increased red blood cell fragility
Therapeutic Effects:
None
Toxicity:
None
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Iodine
Structure: Iodide salts and bound to proteins andlipids
Food Sources:
Iodized salt, salt water, seafood, sunflower
seeds, mushrooms, eggs, beef liver, peanuts,spinach, pumpkin, broccoli and chocolate
Functions:
Synthesis of thyroid hormones
Thyroxine and Tri-iodothyronine
RDI: 150 g/day for males; 120 g/day forfemales plus 30-50 g/day duringpregnancy/lactation
http://en.wikipedia.org/wiki/Image:Thyroxine.png -
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Iodine
Deficiency:
Enlargement of thyroid gland, myxedema, cretinism, increase
in blood lipids
Therapeutic Effects:
None
Toxicity:
Hyperthyroidism (thyrotoxicosis)
Japanese eating too much iodine-rich seaweed
Iodine supplementation as a treatment for goitre
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Chromium
Deficiency:
Glucose intolerance, abnormalities in glucose and lipid
metabolism, elevated circulating insulin, Syndrome X
Therapeutic Effects:
Improve insulin resistance?
Fat metabolism?
Toxicity:
None
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Fluoride
Structure: as salts
Food Sources:
Mackerel, sardines, salt pork, salmon, shrimp, meat, sunflower
seeds, kale, potato, watercress, honey, wheat; drinking watercontent varies
Functions:
Maintenance of teeth and bone structure
RDI: None: drinking water may be fluoridated to 1 ppm
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Fluoride
Deficiency:
Dental caries, osteoporosis
Therapeutic Effects:None
Toxicity:
Brittle bonesIncreased risk of fractures
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Other Trace Elements
Aluminium
No function
Alzheimer's disease
Molybdenum
Co-factor for urease enzyme
Cobalt
Vitamin B12
Arsenate
Vanadium
Silicon
nickel