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Chapter 8
The
Minerals
and Water:
A Functional
Approach
Ask yourself:
True or False:
1. Water accounts for about 60 percent of an
adult’s body weight.
2. Milk is necessary for children, but adults
can find replacements for it.
3. It is generally harder for women than for
men to obtain diets that are adequate in
iron.
4. Sodium is bad for the body and should be
avoided.
5. When a person becomes deficient in iron,
the very first symptom to appear is anemia.
6. Zinc is toxic in excess.
7. Both too little and too much iodine in
the diet can cause swelling of the
thyroid gland, known as goiter.
8. A diet high in salt is associated with
high blood pressure in some
individuals.
9. Osteoporosis is a disease that can
affect men and women at any age.
10. Bone damage is associated with
smoking cigarettes.
The Minerals
• Do not contribute calories.
• Have diverse functions in the body and
work with enzymes to facilitate chemical
reactions.
• Required in very small amounts.
• Are inorganic compounds occurring
naturally in the earth’s crust.
• Contribute to the building of body
structures.
Two Classifications of Minerals
The Major Minerals
• Calcium
• Phosphorus
• Magnesium
• Sodium
• Chloride
• Potassium
• Sulfur
The Trace Minerals
• Iodine
• Iron
• Zinc
• Copper
• Fluoride
• Selenium
• Chromium
• Molybdenum
• Manganese
Two Classifications of Minerals
• Major minerals
Occur in large quantities in the body and
are needed daily in the diet in large
amounts.
• Trace minerals
Occur in minute quantities and are needed
in smaller amounts in the daily diet.
Be sure to study Table 8-1 A Guide to the
Minerals
Good Sources of Minerals in the USDA MyPlate
Food Guide
Minerals for Healthy Bones
• Calcium
• Phosphorus
• Magnesium
• Fluoride
Vitamins important
in healthy bone:
• Vitamin C
• Vitamin D
• Vitamin K
Minerals for Healthy Bones
• Bones are made up of
complex living tissue
based on the protein
collagen
• Crystals of calcium and
phosphorus (and some
other minerals) are
deposited into this matrix
• Two forms:
– Trabecular (lacy
portion)
– Cortical (outer portion)
A Bone’s Life: Bone is living tissue that continuously remodels itself.
Lacy, spongy trabecular bone
The bone marrow within bones
serves to produce new blood cells.
Hard, compact cortical bone
Blood vessels supply bones with
nutrients and oxygen vital for
their health.
Peak bone mass occurs at ~30 years of age. Afterwards, bone loss
starts to outpace bone deposition.
Minerals for Healthy Bones
Calcium
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Bones store 99% of the body’s calcium, which
plays two roles:
Supports and protects soft tissues.
Serves as a calcium bank, providing calcium to
the body’s fluids.
About 1% is in body fluids
Essential for nerve impulses, muscle contraction,
heartbeat, maintenance of blood pressure, &
blood clotting.
Calcium serves as a cofactor for several
enzymes.
Cofactor
A mineral element that, like a coenzyme, works
with an enzyme to facilitate a chemical reaction.
Minerals for Healthy Bones
Calcium
• Needed to support the growth of teeth and
bones.
• A deficit during growing years and in
adulthood can contribute to
osteoporosis.
• Osteoporosis
• Also known as adult bone loss; a disease
in which the bones become porous and
fragile.
– osteo = bones
– poros = porous
Minerals for Healthy Bones
Reasons for Loss of Bone Density:
Poor calcium intake
Fluoride and/or vitamin D deficiency
Heredity
Abnormal hormone levels
Alcohol consumption
Some prescription medicines or other
drugs
• Lack of exercise, especially weight-bearing
exercise
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Calcium Recommendations
Calcium appears in 3 classes of foods:
1. Milk and milk products
2. Green vegetables
3. A few fish and shellfish
• Milk and milk products tend to contain the most
calcium.
 Milk contains both vitamin D and lactose
which enhance calcium absorption and
promote bone health.
• Green vegetables and some other foods may
contain binders which can decrease calcium
absorption.
• Binders
• In foods, chemical compounds that can
combine with nutrients (especially
minerals) to form complexes the body
cannot absorb. Examples are:
Phytic acid: renders the calcium, iron,
zinc, and magnesium in certain foods
less available than they might be
otherwise.
Oxalic acid: also binds calcium and
iron.
• A high fiber intake can also diminish
calcium absorption.
Minerals for Healthy Bones
• Calcium-fortified foods are available for those who
cannot take milk products.
• Milk allergy: the most common food allergy;
caused by the protein in raw milk.
• Lactose intolerance: an inherited or acquired
inability to digest lactose as a result of a failure to
produce the enzyme lactase.
Minerals for Healthy Bones
Phosphorus
• Combined with calcium
to form calcium
phosphate; gives
rigidity to bones and
teeth.
• Part of DNA and RNA;
necessary for all
growth; genetic code.
• Plays major role in
energy production as a
component of enzymes
and B vitamins.
• Transports nutrients.
Minerals for Healthy Bones
Sources of Phosphorus
Phosphorus is found in virtually all foods and the requirement is easy
to meet. A high intake of phosphorus can interfere with calcium
absorption.
Minerals for Healthy Bones
Magnesium
• Acts in all cells of
muscle, liver, heart
and other soft tissues.
• Helps relax muscles
after contraction.
• Bone magnesium is a
reservoir.
• Deficiency not likely
but can occur in
certain conditions.
Minerals for Healthy Bones
Sources of Magnesium
Minerals for Healthy Bones
Fluoride:
• Only a trace amount is found in the body but
its continuous presence is desirable:
– Protects teeth from decay.
– Makes bones of older individuals more
resistant to bone loss (osteoporosis).
• Drinking water is the usual supply of fluoride
and is an effective means to prevent dental
cavities.
Minerals for Healthy Bones
Alternatives to water
fluoridation:
Fluoride toothpastes
Fluoride treatments for
teeth
Fluoride tablets & drops
In some communities, the
natural fluoride
concentration may be
high.
Fluorosis
Discoloration of the
teeth from ingestion
of too much fluoride
during tooth
development.
Fluoridation in the United States
Minerals for Healthy Blood
• Iron
• Zinc
• Copper
All associated with hemoglobin
Minerals for Healthy Blood
Iron
• The body’s oxygen carrier:
Bound into the protein hemoglobin
in red blood cells.
Hemoglobin
The oxygen-carrying protein of the
blood; found in the red blood cells.
Iron helps transport oxygen from
lungs to tissues and thus aid the
release of energy from fuels to do the
cell’s work.
Minerals for Healthy Blood
Iron
• When the iron supply is too low, irondeficiency anemia occurs.
• Iron-deficiency anemia: a reduction of the
number and size of red blood cells and a loss
of their color because of iron deficiency.
• Symptoms of iron-deficiency anemia include:
 Weakness and/or fatigue
 Apathy
 Headaches
 Increased sensitivity to cold
 Paleness
Minerals for Healthy Blood
Two Forms of Iron:
• Heme iron:
Bound into iron-carrying
proteins like hemoglobin.
 Found in meat, fish, and
poultry.
 More reliably absorbed.
• Nonheme iron: found
in plant and animal
foods.
 Not as reliably absorbed.
You can combine foods to achieve maximum iron absorption--the heme
iron in the meat and the vitamin C in the tomatoes in this chili help you
absorb the nonheme iron from the beans.
Minerals for Healthy Blood
Enhance iron
absorption:
• Heme iron
• Vitamin C
Interfere with iron
absorption:
• Foods containing phytic
acid (occurs in some
fruits, vegetables, and
whole grains)
• Tannins (occur in black
tea, cola, coffee,
chocolate, and red
wine)
• Fiber—resulting in
increased transit time
of foods through
intestines
Minerals for Healthy Blood
• Contamination Iron:
 Iron obtained from
cookware or soil can
increase iron intake
significantly.
• Iron Toxicity:
 Large amounts of iron
can be toxic.
• Iron overload: a
condition in which the
body absorbs excessive
amounts of iron; tissue
damage can occur.
Minerals for Healthy Blood
Minerals for Healthy Blood
Zinc
• Found in every cell of the body and present in
enzymes that regulate:
 Cell multiplication and growth.
 Metabolism of protein, carbohydrate, fat, and
alcohol.
 Disposal of free radicals.
• Involved in utilization of vitamin A, taste
perception, thyroid function, wound healing.
 Zinc’s role in preventing colds has been
inconclusive.
Minerals for Healthy Blood
Sources of Zinc
Zinc is highest in foods of high protein content. Two servings of animal
protein per day will generally provide most of the zinc needed daily.
Excess zinc through supplementation should be avoided.
Minerals for Healthy Blood
Zinc Deficiency:
• Symptoms include:
 Night blindness
 Hair loss
 Poor appetite
 Susceptibility to
infection
 Poor wound healing
 Decreased sensitivity to
taste and smell
 Poor growth in children
The Egyptian boy in this picture is 17
years old but he is only 4 feet tall
Minerals for Healthy Blood
Copper
• A trace mineral involved in a variety of
metabolic and physiologic processes
including:
Making red blood cells.
Manufacturing collagen.
Healing wounds.
Maintaining the sheaths around nerves.
• Good food sources include whole grains,
nuts, seeds, legumes and shellfish
Minerals for Energy Metabolism
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Iron
Zinc
Iodine
Chromium
Sulfur
Selenium
Minerals for Energy Metabolism
Chromium
• This trace mineral works closely with the
hormone insulin to help cells take up
glucose and break it down for energy.
• Good food sources include dark chocolate,
nuts, mushrooms, asparagus and whole
grains.
Minerals for Energy Metabolism
Sulfur
• Present in some amino acids and all
proteins.
• No recommended intake.
• No known deficiencies unless the
person is protein deficient.
Minerals for Energy Metabolism
Iodine:
• Part of thyroid hormone, which regulates body
temperature, metabolic rate, reproduction, and
growth.
• Controls the rate at which cells use oxygen and
energy.
• Present in soil in coastal areas of the country.
• Iodized salt was introduced as a preventative
measure to prevent deficiency diseases.
– A recent emergence of goiter in the U.S.
indicates the importance of continued use of
iodized salt.
Minerals for Energy Metabolism
Iodine
• Goiter
• Enlargement of the
thyroid gland caused
by iodine deficiency.
• Cretinism
• Severe mental and
physical retardation of
an infant caused by
iodine deficiency
during pregnancy.
Minerals for Energy Metabolism
• Amount in food
reflects amount in
the soil where
plants are grown
or animals are
raised
• ½ teaspoon iodized
salt meet the daily
requirement
Minerals for Energy Metabolism
Selenium:
• A trace mineral found in the soil.
• Necessary for synthesis of thyroid hormone
that regulates body’s metabolic processes
• Functions as part of the antioxidant enzyme
system that defends the body from free radical
formation.
• Deficiency found in areas with little selenium in
the soil
• Good sources include whole grains, meat,
seafood, and fruits and vegetables
Water, Minerals, and Fluid Balance
• Water is
indispensable for life
and essential for
health.
• Nutrient most
needed by the body.
• A combination of
hydrogen and
oxygen atoms.
• Makes up part of
every cell, tissue,
and organ in the
body.
• Accounts for about
60% of body weight.
Life begins in water
Water, Minerals, and Fluid Balance
30 lb
Protein
Carbohydrate
Vitamins
Minerals
30 lb
Fat
90 lb
Water
150-lb Man
Minerals for Fluid
and Electrolyte Balance
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Sodium
Chloride
Potassium
Phosphorus
Water, Minerals, and Fluid Balance
Fluid Balance
• About 40% of the body’s water is inside the cell,
about 15% is outside the cell, and the remainder
is in blood vessels.
• Cells maintain water balance by pumping minerals
across their membranes and water follows the
minerals.
• Minerals used for this purpose are called ions or
electrolytes.
 Ions: electrically charged particles, such as
sodium and chloride.
 Electrolytes: compounds that partially dissociate
in water to form ions; examples are sodium,
potassium, and chloride.
Water, Minerals, and Fluid Balance
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Electrolytes
Sodium, potassium, and
chloride are examples of
body electrolytes.
Potassium, which is
usually found in the
fluids inside the cells,
carries a positive charge.
Sodium and chloride are
usually found in the
fluids outside the cells.
Sodium carries a positive
charge.
Chloride carries a
negative charge.
Na+ Cl–
Na+ Cl–
Na+ Cl–
Na+ Cl–
Na+ Cl–
Fluid
Na+ Cl–
inside
cells is rich in
potassium (K ).
Fluid outside
cells is rich in
sodium (Na )
and chloride (Cl ).
Water, Minerals, and Fluid Balance
• Maintaining healthy concentrations of
electrolytes is vital to life so that cells
can do their work such as:
Nerve-to-nerve communication
Heartbeat
Muscle contraction
• Electrolytes are lost in sweat, blood and
urine.
– Fluid losses must be replaced to
prevent dehydration and heat stroke.
Water, Minerals, and Fluid Balance
Sodium
• Found naturally in many foods.
• Component of sodium chloride (table salt), a
food seasoning and preservative.
• The use of highly salted foods can contribute to
high blood pressure (hypertension) in those who
are genetically susceptible.
• Hypertension: sustained high blood pressure.
 hyper = too much
 tension = pressure
• Dietary Guidelines for Americans recommend
consuming little sodium and salt and staying
below the upper limit of 2300 mg of sodium per
day.
Water, Minerals, and Fluid Balance
• In general, the more processed a
food is, the more sodium it contains.
– Up to 75% of salt in the U.S. diet has
been added by food processors.
– The salt shaker adds only about 15% of
the total salt consumed daily.
• Many whole foods are low in sodium
and high in potassium.
Choose & Prepare Foods with Less Salt
• At the Supermarket:
 Read the Nutrition
Facts…
 Limit your intake of
cured foods &
condiments
 Cut back on your
intake of prepared
products
 Buy fresh, natural
foods more
frequently
Choose & Prepare Foods with Less Salt
• At Home:
 Flavor foods with herbs, spices, etc…
 Cook without or with less salt
 Rinse canned foods
 Consult the DASH eating plan
• When Eating Out:
 Ask how foods are prepared and if possible,
ask them to not add salt
 Move the salt shaker away
 Limit condiments
 Choose fruits or vegetables instead of salty
snack foods
Water, Minerals, and Fluid Balance
Sources of Sodium
Water, Minerals, and Fluid Balance
Potassium
• Critical to maintaining the heartbeat.
 Sudden deaths that occur due to fasting, severe
diarrhea, or severe vomiting are thought to be due
to heart failure due to potassium loss.
• As the principal positively charged ion inside body
cells, potassium plays a major role in maintaining
water balance and cell integrity.
• Potassium deficiency is dangerous.
 Potassium is lost in dehydration.
 Some diuretics taken to increase water loss also
cause loss of potassium.
 Diuretics
Medications causing increased water excretion.
• dia = through
ouron = urine
Water, Minerals, and Fluid Balance
• Some physicians will prescribe a
potassium supplement for people
taking diuretics.
• Potassium supplementation should
be medically supervised and never
self-prescribed.
Toxicity is the concern rather than a
deficiency
Water, Minerals, and Fluid Balance
• The relationship of potassium and
sodium in maintaining blood pressure is
not clear.
• Increasing potassium in the diet can
promote sodium excretion and may
lower blood pressure.
• A lifelong intake of low-sodium and
high-potassium foods protects against
hypertension.
• A dietary
deficiency of
potassium is
unlikely but highsodium diets that
are also high in
processed foods
and low in fresh
fruits and
vegetables can
make it a
possibility.
Water, Minerals, and Fluid Balance
Sources of Potassium
Water, Minerals, and Fluid Balance
Chloride
• This negative ion accompanies sodium in
the fluids outside the cells.
• It crosses membranes freely and can also
be found inside the cells.
• Helps in maintaining acid–base balance.
• Nearly all dietary chloride comes from salt
or sodium chloride.
Diet & Blood Pressure
RISK FACTORS
• Obesity
• Family history
• Race (African
American)
• Age (increased)
• Excess alcohol
consumption
• Sedentary
lifestyle
Are Your Numbers Up?
Hypertension has been called a “silent killer” because it
cannot be felt and may go undetected for years.
Diet & Blood Pressure
• Diagnosis of hypertension requires at least two
elevated readings.
• Individuals with prehypertension are at increased
risk for progression to hypertension and should
make lifestyle changes such as:
 Losing weight
 Lowering sodium intake
 Decreasing alcohol consumption to moderate
amounts
 Exercising more
An Eating Plan to Reduce High Blood
Pressure
• DASH Diet: Dietary Approaches to Stop Hypertension
• The DASH diet eating plan has been effective in
reducing blood pressure.
• Choose low-fat dairy products, smaller portions of
meat, plenty of fruits and vegetables, and ample
servings of high-fiber, whole-grain products.
 This diet is high in fruits, vegetables, whole
grains, and low-fat dairy products.
 The diet is lower in total fat, saturated fat, and
cholesterol.
 May reduce risk for heart disease, hypertension,
diabetes, osteoporosis and cancer.
Tips to Reduce Hypertension Risk
1. Adopt an eating pattern rich in fruits, vegetables,
legumes, and low-fat-dairy products—similar to the DASH
diet—with reduced saturated fat content.
2. Maintain a normal weight. Lose weight if you’re
overweight; even losing just a few pounds can reduce
blood pressure if you’re overweight.
3. Keep your sodium intake at or below recommended
levels—not more than 2,300 milligrams a day.
4. Pursue an active lifestyle: Walk briskly, swim, jog, cycle,
or other moderately paced aerobic activities. Aim for at
least 30 minutes of activities daily.
5. If you drink, use moderation—no more than one drink a
day for women, and no more than two drinks a day for
men.
6. Don’t smoke. Cigarette smoking raises blood pressure and
increases risk for heart disease.
Osteoporosis
The Silent Stalker of the Bones
• Women generally have less bone mass than men.
• Women typically have lower calcium intakes than men.
• Women more often use weight-loss diets, which tend
to be low in calcium and lead to bone loss.
• Bone loss begins earlier in women because of women’s
different hormonal makeup, and the loss is
accelerated at menopause, when their protective
estrogen secretion declines.
• Pregnancy and lactation decrease the calcium reserves
in bones whenever calcium intake is inadequate.
• Women live longer than men, and bone loss continues
with aging.
Risk Factors
Age (older)
Gender (female)
Age-Related Decline in Hormones
Abnormal absence of menstrual periods
Family History
Race/Ethnic background (Caucasian, Asian)
Body build (thin, small framed, petite)
Sedentary Lifestyle
Smoking and Alcohol
Medical Conditions (often due to prescription
meds)
• Lack of a bone healthy diet including calcium,
vitamin D and other nutrients
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Prevention
• Maximize peak bone mass and be
vigilant about keeping the bones well
supplied with calcium.
• Consume alcohol only in moderation, if
at all, and avoid cigarettes altogether.
• Exercise regularly, because exercise
can reduce the risk of developing
osteoporosis by making bones stronger
and increasing their ability to absorb
calcium.
• For women at or nearing menopause,
talk to your health care provider about
bone loss after menopause