12.1 minerals

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12.1 Minerals Chapter 19 Problem Sets #5 and 6 (Vitamins and Minerals) Chapt 19# 1,2, 5,10,11,17,46

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12.1 Minerals. Chapter 19 Problem Sets #5 and 6 (Vitamins and Minerals) Chapt 19# 1,2, 5,10,11,17,46. Nutritional minerals: the various elements that are essential for proper functioning of the human metabolism, ie. for good health. - PowerPoint PPT Presentation

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Page 1: 12.1   Minerals

12.1 Minerals

Chapter 19

Problem Sets #5 and 6 (Vitamins and Minerals)

Chapt 19# 1,2, 5,10,11,17,46

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MINERALS: Macro- and Micro-

Nutritional minerals: the various elements that are essential for proper functioning of the human metabolism, ie. for good health.

Living beings simply cannot generate minerals in their own bodies.

All of our minerals became part of the earth at its creation and enter our bodies only from the earth, directly through the plants we eat or indirectly from the animals that feed on plants.

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Of the nearly 90 naturally-occurring elements, only 11 of them make up over 99% of the

mass of the human body.

20% Protein, Carbohydrates, Calcium, Phosphorus

Fats 20%

Water 60% Vitamins and all

other minerals (less than 1%)

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Oxygen O 64.6 25.5Carbon C 18.0 9.4Hydrogen H 10.0 63.0Nitrogen N 3.1 1.4Calcium Ca 1.9 0.3Phosphorus P 1.1 0.2Chlorine Cl 0.40 0.06Potassium K 0.36 0.03Sulfur S 0.25 0.05Sodium Na 0.11 0.04Magnesium Mg 0.03 0.01

Element Symbol % by weight % by atoms

Major Elements of the Human Body

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Elements: H ,C ,N ,O, (S)

(from macronutrients)

Macro Minerals: Ca, P, Mg, Na, K, Cl, (S) (over ~400 mg)

Trace Minerals: F, I, Fe, Cu, Zn, Cr, Mo, (under 15 mg) Mn, Co, Se

Probable Trace: Ni, Si, Sn, V, B, As (in animals )

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For the essential nutritional minerals of our diet: the 'metals' are present as cations, eg. Na+,Ca++

the 'non-metals' occur as anions, eg. I-, PO43-

As a consequence they are water-soluble, are excreted and may need to be replaced. Overcooking foods in boiling water will leach out many of the minerals. Many mineral supplements are not as readily absorbable as "natural sources'. Concentrations of many trace minerals are dependant on others, ie. ratios are important.

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The nutrient minerals have varied functions: components of enzymes, structural components in bones and teeth, electrolyte balance in body fluids

and as transport 'vehicles'.

The minerals must be maintained in balanced amounts, with no deficiencies and no excesses.

Many of the body’s minerals, because they are water-soluble, are excreted daily in the feces,

urine and sweat and must therefore be replenished. For most of the minerals, the amount

excreted each day is very nearly the amount ingested.

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There are 46 different minerals in the human body, 21 of which are known to be essential.

The seven macrominerals make up about 4% of body weight. They are calcium, phosphorus, magnesium, sodium, potassium, chloride and

sulfur.

The macrominerals are necessary in building bones, maintaining body fluids, maintaining proper

pH in body tissues, transmitting nerve impulses, maintaining cell membrane structures and

facilitating enzyme action.

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Sodium , potassium and chloride, as ions (Na+,K+, Cl- ), are essential to electrolyte balance in body fluids. Electrolyte balance, in turn, is essential for fluid balance, acid–base balance and transmission of nerve impulses.

When there is extreme fluid loss through vomiting, diarrhea traumatic injury, electrolytes must be supplied to restore their concentration in body fluids .

Sodium (Na+)

Potassium (K+)

Major extracellular ion

Major intracellular ion

Name Function

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Sodium is a vital micronutrient, but is present in most NA diets through excessive intake of salt (sodium chloride). Physicians recommend ingesting about 1.2 grams of sodium/day (or ~ 3gms of salt). This is twice the estimated minimum requirement.

Normal daily urinary excretion of sodium is in the range of 1.4 to 7.8g for adults. If excess sodium is not eliminated, water is retained, which may lead to edema (swollen legs and ankles). Various clinical studies have shown that increased levels of sodium raise the blood pressure of some individuals but have no effect on the blood pressure of others. The high salt diets of 70 g per day in certain areas of Japan have traditionally produced an unusually high frequency of heart attacks .

Many N.Americans exceed the recommended daily intake by 3X. For example, a typical “double burger” contains nearly 1g of sodium.

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Food limerick #1

There was an old fellow called Walt

Who seasoned his food with much salt

His blood pressure rose

From his head to his toes

So his doctor told him to halt!

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Potassium

Though less abundant in the body than its sister element, sodium, is still essential to intra–cellular

enzyme activity and the transmission of nerve impulses.

Peaches, watermelon, bananas and potatoes are rich sources

of potassium and can be eaten to meet the estimated 2g (2000 mg ) daily requirement.

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The regulation of the concentration of K+ relative to Na+ is especially important for the proper

rhythmic beating of the heart.

In the case of some nutrient elements, good health depends on the element being present in the proper amount and in the proper ratio to one

or more other elements.

An example of an important ratio is the potassium/ sodium ratio (K/Na ratio) which has to be within

certain limits to facilitate the transmission of electrical signals between nerve cells .

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Typical values of the K/Na ratio are greater than 1. Some K/Na ratios for specific tissues are: muscle, 4; liver, 2.5; heart,1.8; brain,1.7 and kidney,1.0.

Natural, unprocessed food have high K/Na weight ratios. Fresh, leafy, vegetables average a K/Na ratio of 35. Fresh, non-leafy vegetable and fruits

average a ratio of 360, with extreme values of 3 for beets and 840 for bananas. K/Na ratios in meats

range from 2 to 12.

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Potassium and sodium compounds are quite soluble in water. During processing (and cooking, if foods are boiled), both potassium and sodium compounds are dissolved by water and discarded.

The sodium is replenished by “salting” of the food (addition of sodium chloride). Potassium is usually not added to the food.

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In general

• No nutritional need for us to add salt to our foods

• Already enough present!!

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Calcium

• the major component of bones and teeth • needed for blood clotting, • required for muscle contraction and transmission of other nerve impulses. • slows down the heartbeat by increasing electrical resistance across nerve membranes.

Calcium is metabolized in the body by a hormone synthesized from (vitamin D). Fat slows down calcium absorption but lactose speeds it up.

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Bones and Teeth If mineralization and demineralization occur at the same rate, there is a state of dynamic equilibrium between these two opposing reactions and no net loss results:

Ca5(PO4)3OH 5Ca2+ + 3PO43- + OH-

Substituting F for OH produces a more stable crystal and 100 times less soluble in acids.

NB: -OH + H+ H2O

Excess H+ removes -OH causing demineralization

Demineralization

Mineralization

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Hydroxyapatite fluoride effects

• Structural reinforcement

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Fluoridation of Drinking water

• NaF at 1 ppm level used since 1960 in most Canadian cities: substantial reduction in tooth decay

• Also Sodium monofluorophosphate in toothpaste Na2PO3F: source of F-

• Do we need both?

• Argument against “ Fluoride is toxic”

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Cheaper fluoride sources

• Hydrofluorosilicic acid (HFSA) now used extensively (cheaper than NaF)

• By product of wet scrubbing of phosphate fertilizer factory smokestacks

• CaF2.93Ca3(PO4)2: Fluoroapatite mineral source• H2SiF6 is shipped as a 23% solution, then diluted

180,000 : 1 with municipal water• Contains very low levels of lead and arsenic

impurities

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Gatineau City council decision

• In favour of fluoridation

• Niagara Regional Council: rejected motion to fluoridate on Jan 24, 2008

• Still controversial! Ottawa Citizen Letters to Editor Feb 4, 2008!

• What do you think?

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A deficiency of calcium, usually in older persons and especially in post-menopausal women, can

lead to loss of 'bone density' or brittle bones. The hormone estrogen suppresses bone dissolution.

To maintain good bone density, one should ingest 1) ~1.5g/day of 'soluble' Ca2+; 2) adequate Vit.D

3) adequate Mg2+

This must be accompanied by sufficient weight bearing exercise.

NB. Caffeine in 5-6 cups of coffee/day inhibits Ca uptake by 30%!

Osteoporosis

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Bone Density Profiles

In women over 65/70 more deaths due to'complications' of broken hips/pelvis/vertebrae than from breast

cancer! NB. Increasing number of women not reaching adequate bone density by 30/35 years.

10 20 30 40 50 60 yrs

Dens i t y

+

_

general pop’n, pre 1980 post menopause, pre 1980 general, 2000!

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Why the change over the last 27 years?

• Lifestyles becoming more sedentary

• Poorer nutrition

• Too much caffeine?

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Hormone Replacement therapy (HRT)

• Menopausal women given Estrogen supplements- (recall: estrogen inhibits bone dissolution)

• Also helps control “hot flashes”

• Downside: increases breast cancer risk

• risk/benefit ratio needs to be considered!

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Bone Structure

osteo normal

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Magnesium (Mg++)

Uses: 'energy production'; nerve function; bone & teeth formation; helps regulate heart rhythm; assists blood clotting;aids in insulin function.

RNI (Recommended Nutritional Intake): ~200mg/day

Deficiency: risk of heart disease and diabetes

Sources: whole grains, nuts, legumes, green veggies, shellfish( largely eliminated in processed foods)

Demo: Magnesium in chlorophyll (peas)

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Chorophyll

The “antenna” that plants use to harvest sun’s energy

-Absorbs both red and violet light:hence reflected light appears

green

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Complementary colors absorbed: reflected (seen)

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Cooking green vegetables (peas)

Central magnesium ion (Mg+2) in chlorophyll is replaced by 2 protons (H+)

from citric and malic acids in the food. This changes the amount of E needed to excite the electrons, hence changing the colour:

yukky green peas!!

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Effect of baking soda (NaHCO3)

• Neutralizes the acids in the vegetables

• Green colour maintained (more appetizing)

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A penny for your pots!

• Green chlorophyll colour does not fade when a penny is added to the pot

• Acids in the peas cause a bit of the Cu to dissolve and the Cu+2 ion displaces the Mg+2 in the chlorophyll, producing a more stable complex with a central copper ion.

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Keeping pickles looking fresh and green

• Grandma may have added a penny to the pickle jar! Vinegar will discolour vegetables over time.

• “Canning lime” or “pickling lime”: hydrated CaO used to keep pickles crisper (less mushy). Ca+2 ion displaces Mg+2.

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Phosphorus (PO43-)

Uses: necessary component of bones/teeth, phospholipids and Adenosine TriPhosphate (metabolic energy-transfer agent)

RNI: 1000mg(1g)/day

Deficiency: rare

Sources: meat/fish/poultry, dairy products, colas

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Sulfur (-SH, SO42-)

Uses: component of two amino acids and vitamins; important functional group in 10 protein structure; part of sulfate anion

RNI: not established

Deficiency: unknown

Sources: all protein (plant & animal): from amino acids cystine and methionine

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Essential Trace Minerals

Ten are confirmed as essential for humans:

iron, copper, zinc, manganese, iodine, fluoride, chromium, selenium, molybdenum, cobalt,

Essential for mammals, but not yet confirmed for humans, are:

nickel, vanadium, silicon (plus arsenic, boron, tin)

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Manganese in blueberry juice

• Sharper MRI (magnetic resonance imaging) signals seen for bile ducts and other parts of GI system

• Mn atomic number 25 (electron configuration: 1s2, 2s2,2p6,3s2,3p6,4s2,3d5 has 5 unpaired electrons, hence acts as a relaxation agent for water and faster MRI signals

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Blueberry juice :rich in manganese

• Given to patients at St. Paul’s Hospital Vancouver before MRI scans on GI system.

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Micronutrient Terminology in Canada

RNI (Recommended Nutrient Intakes) - the re- commended amount of essential nutrients for

healthy individuals in each age/gender group.

RDI (Recommended Daily Intakes) - the highest

recommended RNI value for each nutrient (used on food labels).

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Micronutrient Terminology in USA

RDA (Recommended Dietary Allowances) - intake levels of essential nutrients that are 'adequate to meet the known nutritional needs of practically all healthy persons'.

USRDA (Recommended Daily Allowances) - standards for nutritional information on food labels (based on RDAs).

Similar to, respectively, RNI and RDI in Canada

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Nutritional Values - NA 'Harmonization'

Canadian & US nutritional scientists are establishing consistent values for all food-related categories.

These will be called Dietary Reference Intakes (DRIs) and will cover the following categories:

1) calcium, vit.D, phosphorus, magnesium, fluoride; 2) folate and other B vitamins; 3) antioxidants; 4) macronutrients; 5) trace elements; 6) electrolytes and water; 7) fiber and other food components

Compendia for the first two categories are now (2001) published.

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Iodine (I-)

Uses: essential for thyroid gland to produce thyroxine, a hormone that regulates all cell metabolism, ie. growth/development.

RNI: 160 mcg/day

Deficiencies: enlarged thyroid(goiter); severe mental retardation(cretinism) of newborns can occur if pregnant women are deficient.

Sources: salt water fish/vegetation, iodized salt

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Goiter – it’s not pleasant !

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Thyroid gland enlargement

• Expands in an attempt to produce enough thyroxine!

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Iodine deficiency was virtually eliminated in NA in 1924 by a Public Health initiative requiring the inclusion of potassium iodide(KI) in table salt by the Morton Salt Co.

Worldwide ~1.6 billion people still suffer from iodine deficiency.

In the 1990's an epidemic of fetal brain development/mental retardation was reported

from the interior of China leaving ~1 million with some retardation(>100,000 as cretins)!

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Iodized salt

• Mostly NaCl, but KI added

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Also present in salt

• SiO2 (sand!) as a very fine powder

• Stops caking by absorbing moisture

• Not metabolized!

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OH CH

NH2

COOH

O CH2 CH

NH2

COOHOH

I

I

I

I

Thyroxine – the Thyroid Hormone

Thyroxine

Tyrosine(essential a.a.)

I2

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Iron (Fe++)

Iron is part of heme which is critical for the transport of oxygen by hemoglobin and the temporary storage of oxygen in heart muscles by myoglobin.

RNI: 8 - 10mg/day (higher for pregnant women)

Deficiency: anemia( the red blood cells are low in hemoglobin and thus carry a decreased oxygen supply), fatigue, decreased resistance to infection.

Sources: animal protein,seafood, dried fruits, bran

Heme Iron in red meat is best!

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• Anemia can be caused not only by iron deficiency but also 'heredity' or lack of vits. B6, B9 or B12 (pernicious anemia).

•A person with 20% of normal hemoglobin levels still has the energy/strength to walk. •Iron must be absorbed as Fe2+ ions. Iron from

animal sources tends to be better absorbed than that ingested from plant sources or 'pills'.

•Caution, excess iron can be toxic!

•An estimated 20% of North Americans (particularly post-puberty women) have iron deficiencies.

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Iron in your cereal (DEMO)

• Reduced iron : is metallic iron Fe0.

• GER ( Gain of electrons is reduction)

• Fe+3 (ferric) + 3 electrons > Iron

• Fe+2 (ferrous) + 2 electrons > Iron

• Body uses ferrous in heme proteins myoglobin and hemoglobin

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Zinc (Zn++)

Uses: cell growth; proper functioning of immune system

RNI: 9-12 mg/day

Deficiency: poor wound healing; dwarfism (in extreme cases, eg. Middle East).

Sources: protein; available in cheese, beans, nuts, wheat germ but not readily absorbed

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Do Zinc supplements treat the common cold?

• “Zinc is required for the development and activation of T-lymphocytes, a type of white blood cell that helps to fight infection. Zn supplements increase the numbers of T-lymphocytes in the blood and thus help fight infection”

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In general

• It is believed that for Zn lozenges to work, (a) they must be taken at the first signs of a cold, and (b) continued for the duration of the cold.

• Most evidence supports (a) but not necessarily (b).• If (a) works , then (b) should not be needed!!• Often combined with Vit. C, sugar and Echinacea

in formulation

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Zinc lozenges

• Over the counter: take at the 1st sign of a cold

• Boost immune system

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Copper (Cu++)

Uses: structural proteins, nerve cells, pigmentation

Est. ~2mg/day

Deficiencies: poor tendons/ arterial walls, skeletal defects

Sources: nuts, raisins, liver, legumes, shellfish

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Selenium (Se+++)

Uses: antioxidant (anti-cancer?!); reduces blood thickening

Est. 100mcg/day (extremely toxic if >800mcg)

Sources: animal protein; grains if soil has it.

Epidemiological / Statistical correlation: live stock (Great Plains ) and heart disease (Trendy!) .

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Cobalt (Co++)

Uses: essential part of Vit. B12

RNI: Not established (probably mcg)

Deficiences: anemia, growth retardation

Sources: only animal protein

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Chromium (Cr+++)

Use: assists insulin production; helps breakdown protein and fat

Est. ~150mcg/day

Deficiency: increased risk of diabetes

Source: whole grains, nuts, seafood, prunes, potatoes