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Ch. 9 Minerals

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Minerals: overall (3)
1. Carbon atoms in carbohydrates, fats, proteins, and vitamins combine with oxygen to produce carbon dioxide, which goes into the air.
2. Hydrogens and oxygens form water, and along with body water, this evaporates.
3. Ashes are about 5 pounds of minerals .
-About 3/4 is calcium and phosphorus
• Mostly in the bones
-Less than a teaspoon of iron
• Most in hemoglobin protein of RBCs
Minerals & rocks
Mineral
• any naturally occurring solids that is ...
• An element or inorganic compound ...
• And usually has a crystalline structure
Rock
• any natural combination of minerals that make up a part of the earth's crust
Minerals: Basic concepts = What are minerals? (4)
•Elements in Earth's rocks, soil, and natural water sources.
• About 15 (25) mineral elements are essential nutrients.
• Classified as micronutrients because they are required in mg or mcg amounts.
• Minerals cannot be destroyed, but they can be lost from foods.
Why are minerals necessary? (7)
Diverse roles, including:
-Structural components of tissues (ex. bone)
-Ions dissolves in fluids
- Blood clotting (ex. Ca ions)
- Fluid balance
- Acid-base balance
- Cofactors in chemical reactions
- Part of certain enzymes and hormones
cofactor
an ion or molecule that catalyzes chemical reactions
minerals: major vs. trace
1. About 25 elements are essential to life
2. Four of these make up about 96% of the weight of the human body (CHNO)
3. Trace elements occur in smaller amounts
major minerals: definition
1. Major minerals = 7 minerals
- Present in larger quantities than trace
• Amounts greater than 5 grams
major minerals: names (7)
1. calcium
2. phosphorus
3. potassium
4. sulfur
5. sodium
6. chloride
7. magnesium
Trace minerals: definition
Trace minerals -
- Present in smaller quantities than major
• Amounts less than 5 grams
trace minerals: names (5)
1. iron
2. zinc
3. copper
4. iodine
5. many more
sources of minerals (3)
1. Most foods contain minerals (b/c they need it survive)
2. Animal foods generally contain higher amounts of minerals than plant foods.
3. Processing foods often reduces mineral contents.
bioavailability of minerals
1. Bioavailability of minerals varies.
- In general, minerals in animal foods are more easily absorbed than minerals in plant foods.
other sources of minerals (2)
1. Tap water
-"hard " water contains a variety of minerals, including calcium, sulfur, copper, iron, and zinc.
-Most public water supplies provide fluoride.
2. Dietary supplements
-A daily multiple vitamin and mineral supplement
is generally safe for healthy people.
-Supplements of single minerals may be toxic, if taken in excess.
safety & sources of drinking water
Water is practically a universal solvent : it dissolves
almost anything it encounters to some degree.
- Hundreds of contaminants have been detected in public drinking water
properties of water
1."Universal" Solvent - water will dissolve many substances
2. Hydrophilic - Attracts water.
- Usually ionic (minerals) or polar substances (a polar molecule dissolves in water)
3. Hydrophobic - Cannot attract
water.
- Usually non-polar substances
4. A solution contains solutes dissolved in a solvent (usually water).
mineral intakes
Many minerals have a narrow range of safe intake.
As a result, it is relatively easy to consume a toxic amount, especially by taking supplements that only contain a particular mineral.
water follows salt
1. Major minerals form salts that dissolve in body fluids; the cells direct where the salts go; and this determines where the fluids flow because water follows salt.
2. The body controls the flow of water by moving
electrolytes from one place to another
- Cells expend energy to move electrolytes across their membranes
- Water follows the electrolytes as the system tries to maintain equilibrium
3. This accomplished by special transport proteins located in the cells plasma membrane, known as p
salts
- ions held together
- Compounds (minerals) composed of charged particles, known as Ions - charged particles
• Example: NaCl or sodium chloride - table salt -
Na+ and Cl- = salts
electrolytes
- Compounds (minerals) that partially dissociate (dissolve) in water to form ions
pumps: Na & K
Using the Sodium- Potassium Pump most body cells maintain the proper electrolyte balance by pumping sodium out of the cell and potassium into the cell
- 3Na+ out, 2 K+ in
- cells like high K+ inside
- cells like high Na+ outside
Major mineral: calcium
1. The most plentiful mineral in human body
- > 99% is in bones and teeth
- ~ 1% is in extracellular fluid
2. Healthy adults absorb ~25% of calcium
- Absorption increases during growth
- Absorption decreases with advanced age, vitamin D deficiency, diarrhea, and high intakes of phosphorus, oxalic acid, or phytic acid
Calcium functions in order of importance (7)
• Bone formation and maintenance
• Structural component of teeth
• Muscle contraction
• Blood clot formation
• Nerve impulse transmission
• Cell metabolism
• May help control blood pressure and immune functioning
maintaining normal blood Ca levels (2)
1. Thyroid gland
- Secretes calcitonin when blood calcium is too high
• Stimulates osteoblasts (bone building)
2. Parathyroid glands
- Secrete parathyroid hormone (PTH) when blood calcium is too low
• Stimulates osteoclasts (bone breaking)
osteoblasts
bone building
add bone to where there is more stress
osteoclast
bone breaking
tear down bone tissue where there is little stress
bone development & maintenance (2)
1. Bones are constantly remodeling in response to physical stress.
2. • Remodeling involves two types of cells:
Osteoclasts — tear down bone tissue where there is little stress
Osteoblasts — add bone to where there is more stress
sources of Ca in food
fluid milk, yogurt, cheese, broccoli, leafy greens (kale, collard, turnip, bok coy & mustard greens), sardines, tofu (made with calcium sulfate), almonds
-plant foods not as bioavailable as milk & milk products
calcium supplements
1. Calcium Supplements
- Calcium carbonate (hardly absorbed) or citrate (better) with vitamin D (D enhances absorption)
calcium intakes & UL
1. Dietary Adequacy
- AI 1000 to 1200 mg/d (adults)
2. Calcium Toxicity - UL = 2500 mg/d (hypercalcemia)
osteoporosis: definition
A chronic disease characterized by low bone mass and reduced bone structure
- Among people over age 50,
~10 million have osteoporosis and 34 million are at risk.
- Anestimated1.5million Americans have an osteoporosis- related fracture each year.
what contributes to osteoporosis? (7)
• Consuming excess protein, sodium, and caffeine, especially when calcium intake is low
• Excessive alcohol consumption
• Smoking cigarettes
• Family history of osteoporosis
• Menopause
• Prolonged bed rest or physical inactivity
• Certain medications
reducing risk of osteoporosis (2)
Begin early in life with:
- Proper diet • Follow MyPyramid
- Regular exercise • Weight bearing exercise strengthens bones (low-impact aerobics, basketball, running, walking, tennis)
sodium: general
Table salt = sodium + chloride
salt = - 1 tsp salt supplies 2325 mg sodium
sodium: functions (3)
- Major positively charged ion in extracellular fluid
- Conducts nerve impulses
- Involved in transporting glucose and amino acids into cells
sodium: intakes
Only ~ 180 mg sodium required per day
- AI = 1500 mg/d
• AI for sodium does not apply to those who perspire heavily
sodium deficiency
• Deficiency
- May occur when > 2 to 3% of body
weight is lost through sweating
sodium toxicity
• Toxicity
- UL = 2300 mg/d
• Average intake is ~3400 mg/d.
- High sodium intakes associated with increased risk of hypertension
sodium & hypertension
Hypertension - condition characterized by persistently elevated blood pressure
- Affects ~27% of American adults - Hypertension increases risk of:
• Heart disease • Stroke • Kidney failure
blood pressure: systolic
Systolic pressure — maximum blood pressure within arteries when ventricles of the heart contract
blood pressure: diastolic
• Diastolic pressure — pressure when ventricles relax between contractions
potassium: functions
- Major positively charged ion in intracellular fluid
- Needed for nerve impulses, contracting muscles, and kidney function
- Potassium-rich diets may reduce blood pressure
potassium intakes
Dietary Adequacy
- AI = 4700 mg/d
• Most Americans consume ~2700 mg/d
potassium sources
fresh fruits, fruit juice, vegetables, milk, whole grains, dried beans
magnesium: functions
Participates in >300 reactions
• Roles the body include:
- Regulation of muscle and nerve function
- Maintenance of strong bones
- Strengthening the immune system
magnesium intakes
• Dietary Adequacy
- Adult RDA = 310 to 420 mg/d
magnesium sources
green pigment in plants, spinach, leafy green vegetables, whole grains, beans, nuts, seeds & chocolate and milk and some meats
magnesium deficiency
• Rare among healthy Americans
• Most likely in girls between 14-18 yrs of age
magnesium toxicity
• Results from ingesting excessive laxatives, antacids, or dietary supplements
chloride (5)
1. Principle food source - table salt, NaCl
2. Chloride is the body's major negative ion
It is responsible for:
3. - stomach acidity, Hydrochloric acid in stomach
4. - Crucial for fluid balance/assists in maintaining body chemistry
• Follows sodium in fluid outside of cells
• Acid-base balance & Electrolyte balance
5. No known diet lacks chloride.
sulfate: functions, intakes, deficiencies
1. Roles in proteins. it's located in - 2 amino acids have S-containing side group
2. No recommended intake
3. Deficiencies are unknown......
sulfate: general
1. Sulfate is the oxidized form of sulfur as it exists in food and water.
- Affects acid-base balance and electrolyte balance as sulfate ion -SO4-2
• Epsom Salts are MgSO4
2. Used to synthesize sulfur-containing body
compounds.
- Example: Some proteins have their shapes rigidly maintained by -S-S- bonds between certain amino acids
• Curly hair has many of these bonds
Trace minerals: names (7)
1. iodine
2. iron
3. zinc
4. selenium
5. fluoride
6. chromium
7. copper
iron: functions
• Iron is a component of hemoglobin and myoglobin.
• Hemoglobin — iron-containing protein in RBC that transports oxygen to tissues and some CO2 away from tissues
• Myoglobin — iron-containing protein in muscle cells that controls oxygen uptake from RBC
• Iron is involved in energy generation and immune function.
hemoglobin
iron-containing protein in RBC that transports oxygen to tissues and some CO2 away from tissues
myoglobin
iron-containing protein in muscle cells that controls oxygen uptake from RBC
iron: sources
beef, fish, poultry, whole grain & enriched breads and cereals
Not milk
regulating iron (2)
1. Digestive tract absorbs - 5-15% of iron
- Only ~5% of iron from enriched grains is absorbed
2. Most iron stored as ferritin in the liver
- Iron from broken down (& stored as ferritin) hemoglobin is "recycled" and incorporated into new hemoglobin
iron: intakes
• RDA
1. Women = 18 mg/d iron
• Most females from ages 14 to 50 yrs have low intakes.
2. Men = 8 mg/d
• Most males >age 9 yrs have adequate intakes.
anemia
Anemia impairs oxygen transport in blood.
iron toxicity
1. Upper Limit (UL) = 45 mg/d
• May occur in children <6 yrs due to supplement overdose
- Signs include vomiting and diarrhea, progressing to coma and death
hereditary hemochromatosis
Iron Overload: Common hereditary disorder resulting in excess iron absorption
zinc: functions (5)
• A component of hundreds of enzymes and other proteins.
• Wound healing
• Normal of taste and smell
• DNA synthesis
• Immune function
zinc sources
seafood meat, whole grains
zinc deficiency (2)
- Zinc deficiency often occurs in people with chronic digestive tract problems and exclusively breastfed infants.
- Associated with delayed sexual maturation and growth retardation
zinc intake
Adequacy
• Adult RDA ranges from 8 to 13 mg/d
• Children between 6 to 11 yrs at risk of deficiency
zinc toxicity (3)
• Upper Limit (UL) = 40 mg/d
• May reduce HDL cholesterol level
• >100 mg/d results in diarrhea, cramps, vomiting,
and depressed immune system (colds)
iodide functions (3)
• Required for normal thyroid function and production of thyroid hormone
• Thyroid hormone controls metabolic rate.
• In U.S., some table salt is fortified with iodide to prevent deficiency.
iodide intake
Dietary Adequacy
• Adult RDA = 150 mcg/d
iodide toxicity
• UL = 1.1 mg/d
• May result in enlargement of thyroid gland
iodide deficiency (2)
1. Goiter
• Characterized by enlarged thyroid gland
• Common before advent of iodized salt in areas where iodine content of soil was poor
2. Cretinism
• Irreversible condition affecting infants born to women who were iodide deficient during pregnancy
selenium functions (2)
• Part of several proteins called selenoproteins
• Many selenoproteins are antioxidants
• May reduce risk of certain cancers
selenium sources
meat, eggs, fish, seafood, whole grains
selenium intakes
Adequacy
• Adult RDA = 200 mcg/d
• Most Americans meet RDA
selenium deficiency
• May occur with severe digestive tract conditions
selenium toxicity
• Upper Limit (UL) = 400 mcg/d
• Known as selenosis
fluoride: general (4)
1. Not essential to life
2. But fluoride stabilizes bones and makes teeth resistant to decay.
- Bones and teeth are made from Hydroxyapatite (calcium and phosphorous). Flouride replaces a little with Fluorapatite during formation
• a mineral that makes bones and teeth even harder
3. Excess fluoride discolors teeth; large doses are toxic.
4. There is no support that fluoridated water causes cancer
fluoride sources
1. Fluoride is added to drinking water to lessen tooth decay
-This is the usual source of flouride, but watch for mouthwash, infant formula, and supplements
2. Flouride is added to some toothpastes
3. To prevent fluorosis
• Discoloration of the teeth from too much flouride during tooth development
- young children should not swallow toothpaste
- Fluorosis is irreversible, and does not occur after teeth have formed
chromium: general & sources
1. Chromium works with the hormone insulin to control blood glucose concentrations.
- Deficiency causes a diabetes-like condition (but not diabetes!)
- Extra chromium will not build muscle or melt off body fat!
3. Chromium is present in a variety of unrefined foods - liver, whole grains, nuts, and cheeses are good sources.
4. It is estimated that percent of U.S. adults consume less than the recommended minimum intake of 50 micrograms a day.
- Easily lost during food processing
chromium functions (2)
1. May enhance insulin's action on cell membranes • 2. "Holds the door open" for glucose entry into cells
chromium sources
• Widely distributed in foods
Chromium is present in a variety of unrefined foods - liver, whole grains, nuts, and cheeses are good sources.
chromium dietary, deficiency & toxicity
Dietary Adequacy — most diets are adequate Deficiency — causes impaired glucose tolerance Toxicity — not known
Chromium picolinate may damage DNA, but more research is needed.
copper: functions
Copper is needed
1. to form hemoglobin
2. and collagen
3. and assists in many other body functions.
- Interacts with iron in energy-releasing reactions - 4. Is part of a family of major antioxidant enzymes known as superoxide dismutases
• they are proteins cofactored with copper and zinc, or manganese, iron, or nickel.
• Among the most abundant proteins in the body
copper: deficiency, sources & UL
1. Deficiency is rare.
- Excess zinc interferes with copper absorption
- Disturbs growth, metabolism, immunity and blood flow
2. Good food sources include: organ meats, seafood, nuts, and seeds.
- Even copper plumbing is a source
- U.S. intakes adequate
3. UL is 10 milligrams per day
6 possible essential minerals
1. arsenic
2. boron
3. lithium
4. nickel
5. silicon
6. vanadium