Transcript dnt 200 nutrition for health sciences

DNT 200
NUTRITION FOR HEALTH
SCIENCES
WATER & MINERALS
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WATER & MINERALS
The cows are our friends, they give food,
they give strength, they likewise give a
good complexion and happiness
Gautama Buddha, 500 B.C.
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WATER & MINERALS
Water and Body Fluids
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WATER & MINERALS
Water
• Physiological Functions
– Is an essential nutrient (must be consumed from
exogenous sources to satisfy metabolic
demand)
– Constitutes about 60% of adult body weight
– Catalyst for a majority of metabolic reactions
including those involves with
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Nutrient digestion
Absorption
Transport
Metabolism
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WATER & MINERALS
Water
• Physiological Functions (con’t)
– Required for facilitation of excretion of
metabolic waste by the kidneys
– Inadequate intake compromises cell functioning
by contributing to
• Electrolyte imbalances
• Concentration of plasma volume
• Inability to regulate body temperature
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WATER & MINERALS
Water
• Groups vulnerable to dehydration -- are
either not able to adequately express thirst
sensations or to detect them
– Infants
– Elderly adults
– Athletes
• With extreme heat and excessive
perspiration, thirst may lag behind actual
water requirements
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WATER & MINERALS
Water
Overhydration
• Can result in hyponatremia (because of too
much water)
– Less common but more dangerous than
dehydration
– Sports drinks -- contain some sodium but not
enough to make a difference
– Women at greater risk because they are smaller
– International Marathon Medical Directors
Association advises drinking no more than
7
about 12 - 25 oz fluid per hour
WATER & MINERALS
Water and Body Fluids
Water Intake
PERCENTAGE OF WATER IN
SELECTED FOODS
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•
• Sources
– Water you drink
– Nearly all foods
contain water
• Normal intake -- 2.5
liters per day
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100% -- Water; diet sodas
90-99% -- Nonfat milk, strawberries,
watermelon, lettuce, cabbage, celery, spinach,
broccoli
80-89% -- Fruit juice, yogurt, apples, grapes,
oranges, carrots
70-79% -- Shrimp, bananas, corn, potatoes,
avocados, cottage cheese, ricotta cheese
60-69% -- Pasta, legumes, salmon, ice cream,
chicken breast
50-59% -- Ground beef, hot dogs, feta cheese
40-49% -- Pizza
30-39% -- Cheddar cheese, bagels, bread
20-29% -- Pepperoni sausage, cake, biscuits
10-19% -- Butter, margarine, raisins
1-9% -- Crackers, cereals, pretzels, taco
shells, peanut butter, nuts
0% -- Oils
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WATER & MINERALS
Water and Body Fluids
• Percent of total water intake from beverages
(including drinking water) and food
– Males and females 19 and older
• 81% from beverages
• 19% from foods
– Pregnant females
• 77% from beverages
• 22% from foods
– Lactating females
• 82% from beverages
• 18% from foods
NHANES III 1988-1994
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WATER & MINERALS
Water and Body Fluids
Water
DIETARY REFERENCE INTAKE VALUE
• AI
– Males 19 and over -- 0.7 L/day from food and 3.0 L/day
from beverages
– Females 19 and over -- 0.5 L/day from food and 2.2
L/day from beverages
– Pregnant women -- 0.7 L/day from food and 2.3 L/day
from beverages
– Lactating women -- 0.7 L/day from food and 3.1 L/day
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from beverages
2004 data
WATER & MINERALS
Water and Body Fluids
Water Output
• Body must excrete a
certain amount of water
per day as urine (approx.
500ml)
– Carries away waste
products of metabolism
– Above this amount, the
water you excrete adjusts
to balance your intake
– If you drink more than
you need, the urine
becomes more dilute
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WATER & MINERALS
Water and Body Fluids
Fluid & Electrolyte Balance
• 2/3 fluid found inside the cells
• 1/3 fluid found outside the cells
• Major minerals control the movement of
water -- they occur in salts that dissolve in
body fluids
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WATER & MINERALS
Water and Body Fluids
Fluid & Electrolyte Balance
• Ions
– When mineral salts are dissolved in water
(body fluids) they separate (dissociate) into
ions (cations and anions) that carry electricity
– Cations carry positive charges; anions carry
negative charges
• Electrolytes are fluids that have ions
dissolved in them such that they have
electrical properties
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WATER & MINERALS
Water and Body Fluids
Fluid & Electrolyte Balance
Water’s Attraction To Electrolytes
• Electrolyte solutions
– They must have a balanced charge
– Can conduct electricity
• Cells sort out the mineral ions
– Outside the cells -- notably sodium and chloride
ions
– Inside the cells -- potassium, magnesium,
phosphate, and sulfate ions
• When electrolytes move across membranes
water follows -- water follows salt
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WATER & MINERALS
Water and Body Fluids
Fluid & Electrolyte Balance
Water’s Attraction To Electrolytes
• Water moves to concentrated solutions
• Osmosis -- the movement of water across a
membrane to area with more solutes -solutes refer to the number of molecules in
a given volume of solution
• Examples of osmosis
– Raisins plump in water
– Vegetables sweat when salted
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WATER & MINERALS
Water and Body Fluids
Fluid & Electrolyte Balance
Regulation
• The amount of various salts in body must
remain nearly constant
• If salts are lost, they must be replaced from
external sources -- foods and beverages
• Proteins regulate the flow of fluids and ions
– Cell membrane contains transport proteins that
regulate the passage of positive ions and other
substances from one side of the membrane to the
other
– Negative ions follow positive ions
– Water flows toward the more concentrated solution16
WATER & MINERALS
Water and Body Fluids
Fluid & Electrolyte Balance
When someone hasn't consumed
enough fluid...
BRAIN
Hypothalamus responds to high salt concentrations in
the blood by stimulating the pituitary gland
Pituitary gland releases
antidiuretic hormone (ADH)
ADH
Kidneys retain sodium and water, increasing blood volume
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WATER & MINERALS
Water and Body Fluids
Fluid & Electrolyte Balance
When someone hasn't consumed enough
fluid...
KIDNEYS
Kidneys respond to reduced blood flow, releasing renin
Renin
In blood, renin initiates activation
of a protein to angiotensin
Adrenal glands
secrete aldosterone
Angiotensin
Blood vessels
constrict, raising bp
Aldosterone
Kidneys retain sodium and water, increasing blood volume
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WATER & MINERALS
Water and Body Fluids
Dehydration
Signs to watch for (adults)
– Consumption less than 6 cups per day
– Dry mouth, cracked lips, sunken eyes, or
dark urine
– Needs help drinking
– Has trouble swallowing
– Vomiting, diarrhea, or fever
– Confused or tired
– Environmental factors (seasonal
temperatures and room temperatures) 19
What to do
WATER & MINERALS
Water and Body Fluids
Dehydration
– Report observations and warning signs
– Check swallowing
– Encourage drink
• Including other than at meal time
• Caffeinated coffee and tea to be used with caution
due to natural diuretic effect
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Record intake and output
Offer ice chips
Drink with client
Place light pitcher and cup near
Offer assistance
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WATER & MINERALS
Minerals
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WATER & MINERALS
Minerals
Overview
• Are inorganic elements
– Always retain their chemical identity
– Once they enter the body, they remain there until
excreted
• Some are required in small amounts and therefore
are essential nutrients
– Bioavailability varies -- some foods contain binders that
combine chemically with minerals preventing
absorption
– Have varied roles
• Major minerals are present in the largest amounts
(larger than 5 grams)
• Trace minerals -- found in amounts less than 5
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grams
WATER & MINERALS
Minerals
Overview
Minerals in a 60 Kilogram Person
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© 1996 West Publishing Company
Slide 12-9
WATER & MINERALS
Minerals
Major Minerals
Calcium
DIETARY REFERENCE INTAKE VALUE
• AI
– Adults 19-50 -- 1000 mg NOTE: Values do not change
with pregnancy and lactation
– Adults over 50 -- 1200 mg
• UL -- 2500 mg
1998 data
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WATER & MINERALS
Minerals
Major Minerals
Calcium
• Is the most abundant mineral in
the body
• Chief functions
– With phosphorus, is the chief
mineral of the bones and teeth
• 99% stored in bones
• Bones act as a bank for calcium
• Formulation and dissolution takes
place every minute, day and night
• Blood calcium changes in response to
changed regulatory control, not diet -bones are depleted by calcium
deficiency
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WATER & MINERALS
Minerals
Major Minerals
Calcium
• Chief functions (continued)
• Calcium balance
– Regulated by Vitamin D, calcitonin (from the
thyroid gland), and parathormone (from the
parathyroid glands)
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WATER & MINERALS
Minerals
Major Minerals
Calcium
• Chief functions (continued)
• Calcium balance
– If blood calcium is too high
» Rising blood calcium signals the thyroid gland
to secrete calcitonin, which
--Limits calcium absorption in the intestines
--Inhibits the activation of Vitamin D
--Stimulates calcium excretion in the kidneys
--Inhibits osteoclast cells from breaking down
bone, preventing a rise in blood calcium
» All of these actions lower blood calcium, which
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inhibits calcitonin secretion
WATER & MINERALS
Minerals
Major Minerals
Calcium
• Chief functions (continued)
• If blood calcium is too low
» Falling blood calcium signals the
parathyroid glands to secrete
parathormone
» Vitamin D enhances absorption in the
intestines
» Parathormone stimulates the activation of
Vitamin D
» Vitamin D and parathormone stimulate
osteoclast cells to break down bone,
releasing calcium into the blood
» All of these actions raise blood calcium,
which inhibits parathormone secretion 28
WATER & MINERALS
Minerals
Major Minerals
Calcium
• Chief functions (continued)
– Aids in normal muscle contractions and
relaxations -- maintains normal heart rhythm
• Above normal blood levels causes calcium rigor -muscles contract resulting in hardness and
stiffness
• Below normal levels cause calcium tetany -intermittent spasm of the extremities
• Not reflective of lack of dietary calcium
– Are caused by lack of Vitamin D or
– Abnormal secretion of the regulatory hormones
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WATER & MINERALS
Minerals
Major Minerals
Calcium
• Chief functions (continued)
– Blood pressure
• Adequate calcium intake can lower blood
pressure, superceding the effects of a high sodium
diet
– Assists in nerve functioning
– Is involved in blood clotting
– Aids in immune defenses
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WATER & MINERALS
Minerals
Major Minerals
Calcium
• Deficiency symptoms
– Stunted growth in children
– Osteoporosis (adult bone loss)
• Is a reduced density of the bones
• Both genetic and environmental factors can contribute
• Is 8 times more prevalent in women than men
– Women tend to consume less calcium than men
– Women’s bone mass is lower than men (because of smaller body
size)
– Bone loss begins earlier in women than men accelerates after
menopause
• Other nutrients also are involved in preventing
osteoporosis
– Magnesium
– Fluoride
– Vitamin A
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WATER & MINERALS
Minerals
Major Minerals
Calcium
• Toxicity symptoms
– Constipation
– Increased risk of
urinary stone formation
and kidney dysfunction
– Interference with
absorption of other
minerals
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WATER & MINERALS
Minerals
Major Minerals
• Absorption
Calcium
– Adults absorb about 30% of calcium
consumed
– Factors that enhance absorption
• Stomach acid -- helps to keep it soluble
• Vitamin D -- helps the absorptive cells of the
intestine make the necessary calciumbinding protein
• Lactose
• Phosphorus when consumed in an equal
amount as calcium
• Growth hormones
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WATER & MINERALS
Minerals
Major Minerals
• Absorption
Calcium
– Factors that inhibit absorption
• Lack of stomach acid
• Vitamin D deficiency
• High phosphorus intake
• High fiber diet
• Phytates, a non-nutrient component of plant
seeds (in seeds, nuts, and grains)
• Oxalates, a binder (in beets, rhubarb, and
spinach)
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WATER & MINERALS
Minerals
Major Minerals
Calcium
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•
Significant Sources
Milk and milk
products
Small Fish (with
bones)
Tofu (bean curd)
Greens (broccoli,
chard)
Legumes
Broccoli: 36mg per 1/2 cup cooked
Sardines: 324mg per 3 oz
Milk: 316mg per cup
Pork and beans: 77mg per 1/2 cup
Cheddar Cheese: 305mg per 1-1/2 oz
Almonds: 80mg per 2 Tbsp.
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WATER & MINERALS
Minerals
Major Minerals
Phosphorus
DIETARY REFERENCE INTAKE VALUE
• RDA
– Adults over 19 -- 700 mg
• UL
– 3000-4000 mg, depending on age, sex,
pregnancy, or lactation status
1998 data
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WATER & MINERALS
Minerals
Major Minerals
Phosphorus
• After Calcium, is the second-most abundant
mineral in the body
• Approximately 85% is found as
hydroxyapatite, the major calciumcontaining crystal of the bones and teeth
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WATER & MINERALS
Minerals
Major Minerals
Phosphorus
• Chief functions
– A chief mineral of the bones and
teeth
– Phosphates occur in all cells as part
of a major buffer system
(phosphoric acid and its salts)
– Occurs as part of genetic material
• DNA and RNA present in every cell
• Therefore necessary for growth
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WATER & MINERALS
Minerals
Major Minerals
Phosphorus
• Chief functions (continued)
– Assists in energy transfers during cellular
metabolism
• Many enzymes and the B-vitamins become active
only when a phosphate group is attached
• ATP, the energy carrier of the cells, uses three
phosphate groups to do its work
– Part of phospholipids
• Helps transport other lipids in the blood
• Major structural components of cell membranes
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WATER & MINERALS
Minerals
Major Minerals
Phosphorus
• Deficiency symptoms
– Weakness, bone pain
• Dietary deficiency rarely occurs
• Some drugs can bind with phosphorus making it
unavailable resulting in bone loss that is
characterized by weakness and pain
– Diets that provide enough protein and calcium
will provide enough phosphorus
• Toxicity symptoms
– Excess phosphorus may draw calcium out of
the body in being excreted
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WATER & MINERALS
Minerals
Major Minerals
Phosphorus
• Significant sources
– All animal tissues -- best sources
– Phosphorus from additives in processed foods
can add significantly to people’s intakes
– Vegetables and fruits are fair to poor sources
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WATER & MINERALS
Minerals
Major Minerals
Magnesium
DIETARY REFERENCE INTAKE VALUE
• RDA
–
–
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–
Males 19-30 -- 400 mg
Males 31 and over -- 420 mg
Females 19-30 -- 310 mg
Females 31 and over -- 320 mg
• UL
– 350 mg, (as a pharmacological agent only -- not
42
from food and water)
1998 data
WATER & MINERALS
Minerals
Major Minerals
Magnesium
• Bone magnesium is a
“reservoir” to make
sure some will be on
hand for vital
reactions, regardless
of recent dietary intake
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WATER & MINERALS
Minerals
Major Minerals
Magnesium
• Chief functions
– Involved in bone mineralization -- over half of the
body’s magnesium is in the bones
– Building of protein -- acts in all of the cells of the
soft tissue
– Enzyme action
• Is a catalyst in the reaction that adds the last phosphate to
ATP
– Normal muscle contraction
• Dynamic interaction with calcium (calcium promotes,
magnesium inhibits)
– Nerve impulse transmission
– Maintenance of teeth -- holds calcium in the tooth
enamel
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– Supports functioning of the immune system
WATER & MINERALS
Minerals
Major Minerals
Magnesium
• Deficiency symptoms
– Rarely occur without disease -- may develop in
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Alcohol abuse
Protein malnutrition
Kidney or endocrine disorders
Prolonged vomiting or diarrhea
– Characterized by
• Weakness
• Confusion
• If extreme
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Convulsions
Bizarre muscle movements
Hallucinations
Difficulty swallowing
Growth failure in children
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WATER & MINERALS
Minerals
Major Minerals
Magnesium
• Toxicity symptoms -- unknown
46
WATER & MINERALS
Minerals
Major Minerals
Magnesium
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•
Significant Sources
Nuts
Legumes
Whole Grains
Dark Green Vegetables
Seafood
Chocolate
Cocoa
Oysters: 93mg per 3 oz
Dried Figs: 33mg per 1/4 cup
Black Eyed Peas: 45mg per 1/2 cup cooked
Spinach: 78mg per 1/2 cup cooked
Baked Potato: 55mg per whole small potato
Sunflower Seeds(shelled): 21mg per 2 tbs.
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WATER & MINERALS
Minerals
Major Minerals
Sodium
DIETARY REFERENCE INTAKE VALUE
• AI
– Men and women 19 - 50 -- 1500 mg daily
– Men and women 51 - 70 -- 1300 mg daily
– Men and women 70 and older -- 1200 mg daily
• UL
– Men and women 19 and over 2,300 mg daily
• Typical consumption averages 3,300 mg
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2004 data
WATER & MINERALS
Minerals
Major Minerals
Sodium
• Chief functions
– Is the principle electrolyte in the extracellular fluid
and the primary regulator of extracellular fluid
volume
• When blood sodium rises (as when a person eats salted
foods) thirst ensures that the person will drink until the
appropriate sodium to water ratio is restored
– With chloride and potassium, maintains the cells
normal fluid balance
– Maintains acid-base balance
• Kidneys excrete hydrogen ions in exchange for sodium
ions
– Nerve impulse transmission
– Muscle contraction
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• Deficiency
WATER & MINERALS
Minerals
Major Minerals
Sodium
– Causes of depletion
•
•
•
•
Overly strict use of low sodium diets
Vomiting
Diarrhea
Heavy sweating
– Symptoms
• Muscle cramps
• Mental apathy
• Loss of appetite
– When blood sodium drops, both sodium and water
must be replaced to restore balance
• Salt losses can be safely replaced with “regular foods”
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• Salt tablets are not recommended -- too much salt,
especially with too little water can incur dehydration
WATER & MINERALS
Minerals
Major Minerals
Sodium
• Toxicity
– Prolonged excessive sodium intake , especially
when the sodium is derived from salt, may be
related to the development of hypertension in
sensitive people
– Immediate symptoms
• Edema
• Hypertension
• Typically not a problem as long as water needs are
met
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WATER & MINERALS
Minerals
Major Minerals
Sodium
52
WATER & MINERALS
Minerals
Major Minerals
Sodium
• Sodium in foods
– Table salt
• Is about 40% sodium
• 1 tsp. of table salt contains about 2000 mg of
sodium
• 15% of the sodium in the U.S. diet comes from salt
added during cooking
– Processed foods have the highest sodium
contents
• 3/4 of the sodium in the U.S. diet comes from salt
added to foods during processing and manufacturing
– Do not always taste salty -- may contain sodium without
its chloride
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WATER & MINERALS
Minerals
Major Minerals
SODIUM IN SELECTED FOODS
• 1 portion fruit -- 0 mg
• 1 cup milk -- 100 mg
• 3/4 cup corn flakes -- 172 mg
• 1/2 cup instant vanilla pudding -- 372 mg
• 1 cup cottage cheese -- 700 mg
• Big Mac -- 890 mg
• 1 Tbsp. Soy sauce -- 1,027 mg
• 3 oz sausage -- 1,100 mg
• 1 large pickle -- 1,450 mg
• KFC 2-piece combo -- 1,801 mg
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WATER & MINERALS
Minerals
Major Minerals
Chloride
DIETARY REFERENCE INTAKE VALUE
• AI
– Adults 19-50 -- 2.3 grams per day
• UL
– Adults 19 and over -- 3.5 grams per day
• Typical consumption averages 3,300 mg daily
2004 data
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WATER & MINERALS
Minerals
Major Minerals
Chloride
• Chief functions
– Fluid and electrolyte balance
• Major anion of the extracellular fluids (occurs
mostly in association with sodium)
• Associates with potassium inside the cells -- Can
move freely across the cell membranes
– Part of the hydrochloric acid found in the
stomach -- is necessary for proper digestion
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• Deficiency
WATER & MINERALS
Minerals
Major Minerals
Chloride
– Does not occur under normal circumstances
– Sodium depleting conditions such as heavy sweating,
or chronic diarrhea and vomiting also deplete
chloride
– Symptoms
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•
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Growth failure in children
Muscle cramps
Mental apathy
Loss of appetite
Death (uncommon)
• Toxicity
– Normally harmless
– Only known cause is dehydration due to water
deficiency
– Symptomized by vomiting
57
WATER & MINERALS
Minerals
Major Minerals
Chloride
• Chloride in foods
– Table salt -- is about
60% chloride
– Large amounts in
processed foods
– Moderate quantities in
whole unprocessed
foods
58
WATER & MINERALS
Minerals
Major Minerals
Potassium
DIETARY REFERENCE INTAKE VALUE
• AI
– Adults 18 and over --4.7 g/day
2004 data
59
WATER & MINERALS
Minerals
Major Minerals
Potassium
• Chief functions
– Is the principle electrolyte in the intracellular fluid
– With chloride and sodium, maintains the cells
normal fluid balance
– Supports cell integrity
– Nerve impulse transmission
– Muscle contraction -- is critical to maintaining the
heartbeat
60
WATER & MINERALS
Minerals
Major Minerals
Potassium
• Deficiency
– Dietary deficiency unlikely but diets low in
fresh fruits and vegetables make it possible
– Accompanies dehydration
– Regular use of certain drugs
• Potassium depleting diuretics
• Steroids
• Strong laxatives
– Characterized by
•
•
•
•
Muscular weakness
Paralysis
Confusion
Death
61
WATER & MINERALS
Minerals
Major Minerals
• Toxicity
Potassium
– Does not result from overeating foods high in
potassium
• Given more potassium than the body needs, the
kidneys accelerate their excretion
• Vomiting reflex is triggered if ingestion exceeds the
kidneys’ limit
– Can result from overuse of potassium salt (salt
substitutes)
– Characterized by
• Muscular weakness
• Vomiting
– If given into a vein, can stop the heart
62
WATER & MINERALS
Minerals
Major Minerals
Potassium
• Potassium in foods
– All whole foods are good sources
• Meats
• Milk
• Fruits
• Vegetables
• Grains
• Legumes
63
WATER & MINERALS
Minerals
Major Minerals
Sulfur
DIETARY REFERENCE INTAKE VALUE
• Sulfur -- None
• Sulfate -- Requirements are met when intakes
include recommended levels of sulfur amino acids
– Neither an EAR nor AI are established
– Insufficient information is available to establish an UL
2004 data
64
WATER & MINERALS
Minerals
Major Minerals
Sulfur
• Body does not use sulfur by itself as a nutrient but
it occurs in essential nutrients that the body does
use
65
WATER & MINERALS
Minerals
Major Minerals
Sulfur
• Sulfate
– Inorganic sulfate (SO42-) required for the synthesis of
3’-phosphoadenosine-5’-phosphosulfate (PAPS)(a
sulfate carrier used to transfer sulfate groups to
sulfatides, a component of the myelin sheath in the
brain, and in the kidney, and retina)
– Significant levels are found in foods and various
sources of drinking water
– Major source is from biodegradation due to body
protein turnover of sulfur-containing amino acids
methionine and cysteine
66
WATER & MINERALS
Minerals
Major Minerals
Sulfur
• Chief functions
– Stabilizes the shape of some proteins
– Component of some amino acids
• Methionine
• Cysteine
– Part of the vitamins biotin and thiamin
– Part of the hormone insulin
– Combines with toxic substances to form
harmless compounds
67
WATER & MINERALS
Minerals
Major Minerals
Sulfur
• Deficiency
– None known
– Protein deficiency would occur first
• Toxicity
– Would occur only if sulfur-containing amino
acids were eaten in excess (in animals, this
depresses growth)
• Significant sources
– All protein-containing foods
68
WATER & MINERALS
Minerals
Trace Minerals
Iodine
DIETARY REFERENCE INTAKE VALUE
• RDA
– 150 micrograms for males & females over 14
• UL
– 1,100 micrograms
– Toxic dose is thought to be over 2,000 micrograms for adults
2000 data
69
WATER & MINERALS
Minerals
Trace Minerals
Iodine
• Traces of the iodine ion (called iodide) are indispensable
to life
• Any iodine that is ingested in foods is converted into
iodide in the GI tract
• Therefore, iodine is the nutrient in food; iodide is how is
used in the body
70
WATER & MINERALS
Minerals
Trace Minerals
Iodine
• Average consumption has increased over the last several
decades and now approximates 200-500 micrograms,
down from a high of 800 micrograms in 1974
– Fast foods use iodized salt liberally
– Iodates are present in dough conditioners used in the baking
industry
– Milk produced by cows exposed to iodide containing
medications and disinfectants provide other sources
71
WATER & MINERALS
Minerals
Trace Minerals
Iodine
• Roles in the body
– Integral part of two thyroid hormones
• T-3 (triiodothyronine), the active form
• T-4 (tetraiodothyronine), commonly known as thyroxin
• Regulates
–
–
–
–
–
–
–
Body temperature
Metabolic rate
Reproduction
Growth
The making of blood cells
Nerve and muscle function
The rate at which the body cells use oxygen
• Is required for the synthesis of thyroid hormones
– Controls the rate at which energy is released from72
energy-yielding nutrients
• Deficiency
WATER & MINERALS
Minerals
Trace Minerals
Iodine
– When deficient, thyroid hormone concentrations fall
• Body responds by increasing thyroid stimulating hormone
(TSH) secretion in a futile attempt to stimulate iodine
uptake by the thyroid gland
• If deficiency persists, thyroid cells enlarge so as to trap as
many atoms of iodide as possible
• Simple goiter results when the gland becomes enlarged
and visible because of iodine deficiency
• Toxic goiter results when people who over-consume foods
containing Goitrogens (thyroid antagonists), antithyroid
substances whose effect is not countered by dietary iodide
– These goitrogens include plants of the cabbage family
– Toxic goiter represents 4% of the cases of goiter
73
WATER & MINERALS
Minerals
Trace Minerals
Iodine
• Deficiency (continued)
– Symptoms
•
•
•
•
Sluggishness
Weight gain
May impair fetal development during pregnancy
Cretinism -- an iodine deficiency disease where, a
maternal deficiency results in mental and physical
retardation in the child
• Goiter
• Poor school performance
74
WATER & MINERALS
Minerals
Trace Minerals
Iodine
• Toxicity
– Symptoms
• Goiter-like thyroid enlargement -- may block the
airways in children and cause suffocation
• Depressed thyroid activity
75
WATER & MINERALS
Minerals
Trace Minerals
Iodine
• Significant sources
– Iodized salt (first began in the
1930’s)
– Seafood
– Plants grown in most parts of
the country (where landmasses
were once under the ocean)
– Animals that graze the above
noted plants
76
WATER & MINERALS
Minerals
Trace Minerals
Iron
DIETARY REFERENCE INTAKE VALUE
• RDA
– Females under 50 -- 18mg
– Females over 50 and males -- 8mg
• UL
– 45mg
2001 data
77
WATER & MINERALS
Minerals
Trace Minerals
78
WATER & MINERALS
Minerals
Trace Minerals
Iron
Absorption
• Normally, only 10-15% of dietary iron is
absorbed
– Increases in response to
• Diminished supply
• Increased need
– Absorption regulated by transferrin (a blood
protein which captures iron from food and
carries it to tissues throughout the body)
79
WATER & MINERALS
Minerals
Trace Minerals
Iron
Absorption
• Food factors
– Heme (the non-protein
component of hemoglobin
bound to the iron carrying
proteins of meat, poultry and
fish) iron is absorbed at a rate
of about 23%
– Non-heme iron (found in
vegetables, grains, eggs,
meat, fish, and poultry) is
absorbed at a rate of 2-20%
80
WATER & MINERALS
Minerals
Trace Minerals
Iron
Absorption
• Food factors (con’t)
– Absorption enhancers
• Meat, fish, and poultry contain MFP factor (a
factor other than heme) that promotes iron
absorption -- even the iron from other foods
eaten at the same time
• Vitamin C, eaten at the same meal, doubles or
triples non-heme iron absorption
• Citric acid (in citrus fruits) and lactic acid (in
milk) from foods
• HCl from the stomach
• Sugars
81
WATER & MINERALS
Minerals
Trace Minerals
Iron
Absorption
• Food factors (con’t)
– Absorption inhibitors
• Tannic acid in tea and coffee interferes with iron
absorption
• Phytates (a non-nutrient component of plant
seeds) and fibers in soy products
• Whole grain cereals and nuts
• Calcium and phosphorus in milk
• Ethylenediamine tetra acetate ([EDTA], added
in food additives to retard crystal formation and
promote color retention)
82
WATER & MINERALS
Minerals
Trace Minerals
Iron
• Chief Functions
– Part of the protein hemoglobin which
carries oxygen to the blood
– Part of the protein myoglobin that
makes oxygen available for muscle
contraction
– Necessary for the utilization of energy
• Works with several electron transport
chain proteins enabling the body to
capture the energy from nutrients
83
WATER & MINERALS
Minerals
Trace Minerals
Iron
Most of the body’s
iron is in the blood
– Iron losses are
greatest when blood
is lost
– Other sources of
loss include urine,
sweat, and shed skin
84
WATER & MINERALS
Minerals
Trace Minerals
Iron
– Worldwide, iron deficiency is the most common
nutritional deficiency
85
WATER & MINERALS
Minerals
Trace Minerals
Iron
• Deficiency
Symptoms
– Weakness, fatigue
• When iron stores are
exhausted, the body
cannot make enough
hemoglobin to fill its
new red blood cells
• They then can’t carry
enough oxygen from
the lungs to the tissues
• Consequently energy
release is hindered
86
WATER & MINERALS
Minerals
Trace Minerals
Iron
• Deficiency Symptoms
(con’t)
– Pallor (abnormally pale skin)
– Reduced resistance to
infection (lowered immunity)
– Inability to concentrate
– Lowered cold tolerance
– Reduced learning ability
– Itching
87
WATER & MINERALS
Minerals
Trace Minerals
Iron
• Deficiency Symptoms (con’t)
– Impaired wound healing
– Concave nails
– Pale nail beds, eye membranes, and palm
creases
– Pica -- an appetite for ice, clay, paste, or other
non-nutritious substances
• Seen in iron as well as zinc deficiencies
• Clears dramatically as soon as iron is added to the
diet
88
WATER & MINERALS
Minerals
Trace Minerals
Iron
• Stages of iron deficiency
– Iron stores diminish
• Measures of serum ferratin reflect iron stores
– Iron being transported within the body
decreases
• Serum iron falls
• Iron carrying protein transferrin increases
(an adaptation that enhances iron absorption)
• The more transferrin and the less iron in the
blood, the more advanced the deficiency is 89
WATER & MINERALS
Minerals
Trace Minerals
Iron
• Stages of iron deficiency (con’t)
– Lack of iron limits hemoglobin
production
• Erythrocyte protoporphryn (the hemoglobin
precursor) begins to accumulate as
hemoglobin (the globular protein of the red
blood cells) and hematocrit (measurement of
the volume of red blood cells packed by
centrifuge in a given volume of blood)
90
values decline
WATER & MINERALS
Minerals
Trace Minerals
Iron
• Iron deficiency and anemia
– Iron deficiency -- refers to depleted body iron
stores without regard to the degree of depletion
or the presence of anemia
– Iron deficiency anemia -- refers to the severe
depletion of iron stores that results in low
hemoglobin concentration and small, pale, red
blood cells
91
WATER & MINERALS
Minerals
Trace Minerals
Iron
• Toxicity Symptoms
–
–
–
–
–
–
–
–
Infections -- bacteria thrive on iron-rich blood
Lethargy
Joint disease
Enlarged liver
Loss of hair
Death by accidental poisoning in children
Amenorrhea
Impotence
92
WATER & MINERALS
Minerals
Trace Minerals
Iron
• Toxicity Symptoms (con’t)
– Iron overload -- known as hemochromatosis
• Usually caused by a genetic disorder that
enhances iron absorption
• Other causes
– Repeated blood transfusions
– Massive doses of supplementary iron
– Hemosiderosis
• Results from long-term over-consumption of iron
• Characterized by large deposits of the iron
storage protein hemosiderin in the liver and other
93
tissues
WATER & MINERALS
Minerals
Trace Minerals
Iron
•
•
•
•
•
•
•
Significant Sources
Red Meats
Fish
Poultry
Shellfish
Eggs
Legumes
Dried Fruits
Navy Beans: 2.2mg per 1/2 cup cooked
Dried Figs: 1.3mg per 1/4 cup
Swiss Chard: 2.0mg per 1/2 cup cooked
Clams: 25.2mg per 3 oz steamed
Sirloin Steak: 2.8 mg per 3 oz cooked
Tofu: 6.7mg per 1/2 cup
94
WATER & MINERALS
Minerals
Trace Minerals
Selenium
DIETARY REFERENCE INTAKE VALUE
• RDA -- 55 micrograms (men & women over
14)
• UL
– 400 micrograms
– Associated with the highest activity of
enzymes that guard against oxidants in the
body
95
2000 data
WATER & MINERALS
Minerals
Trace Minerals
Selenium
• Chief functions in the body
– Part of an antioxidant enzyme (glutathione
peroxidase)
• Prevents free radical formation
(molecules with one or more unpaired
electrons) by donating one of it’s
electrons thus blocking the oxidative
chain reaction before it starts
• Oxidative stress has been implicated in
– The aging process
– Development of cancer, arthritis, cataracts, heart
disease
96
WATER & MINERALS
Minerals
Trace Minerals
Selenium
• Chief functions in the body (con’t)
– Works with Vitamin E -- if free radicals do form
and a chain reaction starts, vitamin E stops it
– Works closely with the enzyme that converts
thyroid hormone to its active form
97
WATER & MINERALS
Minerals
Trace Minerals
Selenium
• Deficiency symptoms
– Predisposition to heart disease (cardiac
tissue becomes fibrous)
– Keshan disease
• The heart disease associated with selenium
deficiency
• Characterized by heart enlargement and
insufficiency -- fibrous tissue replaces the
muscle tissue that normally composes the
middle layer of the walls of the heart
• Prevalent in regions of China and probably
caused by a virus
98
WATER & MINERALS
Minerals
Trace Minerals
Selenium
• Toxicity symptoms
–
–
–
–
–
–
Nausea
Vomiting
Diarrhea
Loss of hair and nails
Lesions of the skin and nervous system
Irritability
99
WATER & MINERALS
Minerals
Trace Minerals
Selenium
• Significant
Sources
– Seafood
– Meat
– Grains, dependant
on soil conditions
– Vegetables,
dependant on soil
conditions
100
WATER & MINERALS
Minerals
Trace Minerals
Zinc
DIETARY REFERENCE INTAKE VALUE
• RDA
– Males over 14 -- 11 milligrams
– Females over 19 -- 8 milligrams
• UL
– 40 milligrams
2001 data
101
WATER & MINERALS
Minerals
Trace Minerals
Zinc
– Absorption rate ranges from 15 to 40%
depending on a person’s zinc status -- if more is
needed, more is absorbed
– Recommendations assume 20% of dietary zinc
is absorbed
– Fiber and phytates bind zinc, limiting its
bioavailability
– Zinc toothpaste reduces plaque
102
WATER & MINERALS
Minerals
Trace Minerals
Zinc
• Chief functions in the body
– Part of the hormone insulin and many enzymes -more than 70 enzymes require it as a co-factor
– Involved with making genetic material and proteins
– Immune reactions
– Transport of Vitamin A
– Taste perception
– Wound healing
– The making of sperm
– Normal development of the fetus -- protects from
heavy metal poisoning (e.g. lead)
103
WATER & MINERALS
Minerals
Trace Minerals
Zinc
• Deficiency Symptoms -- so pervasive that
generalized malnutrition and sickness are more
likely to be diagnosed
– Growth failure in children (even seen in mild
deficiencies)
– Sexual retardation
– Poor sensitivity to taste of salt
– Anorexia
– Poor wound healing
– Hindered digestion and absorption
– Impaired immune response
– Impairs vitamin A metabolism -- vitamin A
deficiency symptoms may appear
104
WATER & MINERALS
Minerals
Trace Minerals
Zinc
• Toxicity Symptoms
– High doses appear to accelerate the
development of atherosclerosis
– Noted in doses greater than 2 grams
•
•
•
•
•
Vomiting
Diarrhea
Fever
Exhaustion
Muscular pain and incoordination
– Noted in doses just a few milligrams above the
recommended intake (especially when taken
regularly over time)
• Lowers the body’s copper content
105
WATER & MINERALS
Minerals
Trace Minerals
Zinc
Significant Sources
• Protein-containing
foods
–
–
–
–
–
Black Beans: 1.0mg per 1/2 cup cooked
Crabmeat: 3.6mg per 3 oz steamed
Yogurt: 2.2mg per cup
Green Peas: 1.0mg per 1/2 cup
Sirloin Steak: 5.5mg per 3 oz cooked
Oysters: 154mg per 3 oz steamed
Meat
Fish
Poultry
Whole grains
Vegetables
106
WATER & MINERALS
Minerals
Trace Minerals
Others
• Copper
DIETARY REFERENCE INTAKE VALUE
– RDA
• 900 micrograms (male & female over 19)
– UL
• 10,000 micrograms
2001 data
107
WATER & MINERALS
Minerals
Trace Minerals
• Copper
Others
–
–
–
–
–
Is a part of several enzymes
Helps to make red blood cells
Involved in making collagen
Ensures proper utilization of iron
Deficiency is rare -- dietary factors such as phytates and high
intakes of vitamin C, zinc, and iron interfere with copper
absorption
– Zinc competes with copper for absorption, -- people taking
over-the-counter zinc pills may develop copper deficiency
– Best sources -- organ meats, seafood, nuts, seeds
108
WATER & MINERALS
Minerals
Trace Minerals
• Manganese
Others (con’t)
DIETARY REFERENCE INTAKE VALUE
– AI
• Males over 19 -- 2.3 milligrams
• Females over 19 -- 1.8 milligrams
– UL
• 11 milligrams
2001 data
109
WATER & MINERALS
Minerals
Trace Minerals
Others (con’t)
• Manganese
– Cooperates with many enzymes helping to facilitate
many of the different metabolic processes
– Widely distributed in foods -- deficiencies have not
been seen in humans
– Toxicity may be severe
• Symptoms
– Brain disease
– Abnormalities in appearance and behavior
110
WATER & MINERALS
Minerals
Trace Minerals
• Fluoride
Others (con’t)
DIETARY REFERENCE INTAKE VALUE
– AI
• Males over 19 -- 3.8 mg
• Females over 14 -- 3.1 mg
– UL
• 10.0 mg
1998 data
111
WATER & MINERALS
Minerals
Trace Minerals
Others (con’t)
• Fluoride
– Aids in formation of tooth crystals that
strongly resist acid & inhibits the growth of
bacteria
– Where diets are high in fluoride, tooth decay is
reduced
– Drinking water is the most significant source - water with 1 ppm fluoride offers the greatest
protection with virtually no risk of toxicity
112
WATER & MINERALS
Minerals
Trace Minerals
Others (con’t)
• Fluoride
– Excess fluoride
during tooth
development can
cause fluorosis
(discoloration and
pitting of tooth
enamel)
113
WATER & MINERALS
Minerals
Trace Minerals
• Chromium
Others (con’t)
DIETARY REFERENCE INTAKE VALUE
– AI
•
•
•
•
Males under 50 -- 35 micrograms
Males 50 and older -- 30 micrograms
Females under 50 -- 25 micrograms
Females 50 and older -- 20 micrograms
2001 data
114
WATER & MINERALS
Minerals
Trace Minerals
Others (con’t)
• Chromium
– Participates in carbohydrate and lipid metabolism
– Works closely with insulin facilitating the uptake
of glucose into the cells
– Deficiencies unlikely; toxicity unknown as a
nutritional disorder
– Best sources -- unrefined foods
•
•
•
•
•
Liver
Whole grains
Nuts
Brewer’s yeast
Cheeses
115
WATER & MINERALS
Minerals
Trace Minerals
Others (con’t)
• Molybdenum
DIETARY REFERENCE INTAKE VALUE
– RDA
• 45 micrograms (Adults 19 and over)
– UL
• 2,000 micrograms
2001 data
116
WATER & MINERALS
Minerals
Trace Minerals
Others (con’t)
• Molybdenum
– Is a working part of many enzymes
– Deficiencies and toxicity unknown as
nutritional disorders
– Sources are widespread to include
•
•
•
•
•
Legumes
Breads & other grains
Leafy green vegetables
Milk
*****
Liver
117
WATER & MINERALS
Minerals
Trace Minerals
• Nickel
Others (con’t)
– Deficiencies harm the liver and other organs
DIETARY REFERENCE INTAKE VALUE
– UL
• 1.0 milligram
2001 data
****
118
WATER & MINERALS
Minerals
Trace Minerals
Others (con’t)
• Silicon
– Involved in bone calcification in animals
DIETARY REFERENCE INTAKE VALUE
– UL
• Not determined
2001 data
***
119
• Boron
WATER & MINERALS
Minerals
Trace Minerals
Others (con’t)
– May play a role in bone development and prevention
of osteoporosis
DIETARY REFERENCE INTAKE VALUE
– UL
• 20 milligrams
2001 data
**
120
• Vanadium
WATER & MINERALS
Minerals
Trace Minerals
Others (con’t)
– No biological function in humans has been identified
DIETARY REFERENCE INTAKE VALUE
– UL
• 1.8 milligrams (based on adverse effects on laboratory
animals)
2001 data
*
121
WATER & MINERALS
Minerals
Trace Minerals
Others (con’t)
• Cobalt
– Mineral in vitamin B-12
– Is not an essential nutrient
• Tin
– Necessary for growth in animals
122