Transcript Chapter 11: Water and the Major Minerals

Chapter 9
Water and
Minerals
Water
 50%-70%
 Muscle
of body weight
contains 73% water
– Fat contains ~20%
 Intracellular
fluid
– Fluid within the cells
 Extracellular
fluid
– Fluid outside the cells
Fluid Balance
Water shifts freely in and out of cells
 Controlled by electrolyte concentration

– Have electrical charges . . .Na, K, Cl, P, Mg, Ca
Osmosis (where an Ion goes, H2O flows)
 Intracellular water volume

– Depends on intracellular potassium and phosphate
concentrations

Extracellular water volume
– Depends on extracellular sodium and potassium
concentrations
where an Ion goes, H2O flows: fig 9:2
Na
Na
Na
Na
Na
H2O
Na
Na
Na
Functions of Water

Body temperature regulation
– Water absorbs excess heat
– Body secretes fluid via perspiration
– Skin is cooled as perspiration evaporates
– Humidity (bad) & fans (good) ~ evaporation

Removal of body waste via urine
– Urea excretion (Nitrogen from Protein breakdown
– Sodium excretion
– Avoid concentrated urine (brownish)

Amniotic fluid, joint lubricants, saliva, bile
Are You Drinking Enough?

Fluid recommendation: 9 cups for women and
13 cups for men as a starting point
Min. 2-4 water bottles/day
Thirst Mechanism
Not reliable
 Concerns for infants, older adults, athletes
 Athletes

– Weigh before and after training session
– Consume 3 cups for every pound lost

Illness (vomiting, diarrhea, fever)
– Get additional water
Ignoring the Thirst Signal
Shortage of water increases fluid
conservation
 Antidiuretic hormone (vassopressin)

– Released by the pituitary gland
– Forces kidneys to conserve water (reduce
urine flow)

Aldosterone
– Responds to drop in blood pressure
– Signals the kidney to retain sodium (water)
Hydration

Loss of 1%-2% of body weight in fluid
– Thirst signal

Loss of 2% or more of body weight causes
muscle weakness (stay hydrated –training)
– Lose significant strength and endurance

Loss of 10%-12%
– Heat intolerance

Loss of 20%
– Coma and death
Too Much Water
 Overburden
 Low
the kidneys
blood electrolyte concentrations
 Blurred
vision
-Confirming your knowledge Q
What is the Minimal amt. of H2O from fluids
that Humans require/day to replace daily loss?

What is the recommended amt. of water from
fluids that women and men require/day?
Minerals
 Various
functions in the body
 Major Minerals
– Require >100 mg /day
– Calcium, phosphorus etc.
 Trace Minerals
– Require < 100 mg/day
– Iron, zinc, selenium etc.
For 5 pts & Make it a Half day???
What do you say?
Go see “Food Inc.” the movie
 Nickelodean theatre (downtown SC)
 3, 5, 7 & 9PM showtimes. . .

– Answer 3 short questions (class website)
– Turn in with TICKET STUB Next Wednesday
– See Trailer
http://www.newsday.com/entertainment/movies/ny-etfood2612909901jun24,0,6046635.story
-Confirming your knowledgeWhat are the 7 Major minerals
required in the body?
1
2
3
4
5
6
7
-Confirming your knowledgeWhat are the 7 Trace minerals
required in the body?
1
2
3
4
5
6
7
Most mineral requirements
are obtained without defic. in
N. American diets
Bioavailability of Minerals


Fe
Mg
Cu
Zn
~Degree of absorption
Affected by binders in plants (oxalic acid, phytic acid)
– Fibrous foods




Animal products are better absorbed
Plants depend on mineral content of soil
Refinement lowers mineral content (i.e. milling Grains)
Mineral-mineral competition (e.g. >>Zinc vs <Copper)
– Avoid mega-supplements (2X RDA): unless prescribed

Vitamins-mineral interactions:
– Iron w/ (Vit C), Calcium w/ (Vit. D) most efficient
Mineral Toxicity
 Trace
minerals are more toxic
– e.g. Fe, stomach irritation
 Result of supplementation
– Presence of contaminants (esp. Lead (Pb))
– Look for the United States Pharmacopeia
(USP)-approved brands (most reliable)
Minerals of Concern in the Diet

Sodium (Na) ~ consume too much >2400mg/day 
Hypertension (HTN) and CVD

Calcium (Ca) ~ not enough, esp. Women  osteoporosis

Iron (Fe) ~ not enough, esp. Women
– Men require
8 mg/day
– Women require 18 mg/ day
 Menstral flow
 Supplements hard to digest ?

All other Major and Trace minerals (ok) ~ balanced diet
– Avoid supplementing to try and balance or optimize
 Leads to mineral competition  deficiencies
Sodium
Table salt (NaCl): 40% sodium, 60% chloride
 95% of ingested sodium is absorbed
 Positive ion in extracellular fluid
 Aldosterone regulates sodium balance
 Key for retaining body water
 Excretion regulated by the kidneys
 Muscle contraction
 Conduction of nerve impulses

Food Sources of Sodium
Most sodium is added by food
manufacturers and restaurants
 Milk and dairy products
 Processed foods
 Sodium content listed on the labels

Sodium Needs
Adequate Intake is 1500 mg for adults
 Body only needs 200 mg to function
 Daily Value is 2400 mg/day
 Upper Level is 2300 mg

 Typical

intake is 4700 mg/day (US)
Sodium-sensitive individuals should restrict
intake (African American)
Calcium
 99%
is in bones and teeth
 Makes
up 40% of all the minerals
present in the body
Absorption of Calcium

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


Amount in body is dependent on amount absorbed
Requires slightly acidic environment and vitamin D
Absorbed in upper part of small intestine
Normally absorb 25% of calcium in food
Increase to ~60% during time of need
– (pregnancy, infancy)
Decreased Absorption of
Calcium
Ca
Rapid intestinal motility
 High fiber intake
(oxalic acid)
 Excess phosphorus
 Vitamin D deficiency
 Polyphenols (tannins) in tea
 Menopause
 Aging
Ca

Ca
Ca
(phytic acid)
Blood Calcium is Regulated
 Blood
level is maintained at the price
of bone calcium
 Blood level can be maintained despite
inadequate calcium intake
 Setting stage for future bone fractures
Functions of Calcium
 Bone
formation and maintenance
 Blood clotting
 Nerve impulse transmission
 Muscle contraction
 Cell metabolism
–Activates various enzymes
Building Higher Bone Mass
Adequate diet
 Healthy body weight
 Normal menses
 Weight-bearing physical activity
 Moderate intakes of protein, phosphorus,
sodium, caffeine
 Non-smoker
 Lower use of certain medications

Food Sources of Calcium
Bone Strength
 Dependent
on bone mass and bone
mineral density
 The
more there is, the stronger the
bone
Calcium Needs
Daily Value is 1000 mg/day
 Adequate Intake is 1000 -1200 mg/day for
adults
 Adequate Intake is 1300 mg/day for
adolescents (9-18 yrs. old)
 Average intake: 800 mg/day for women
and 1000 mg/day for men
 Upper Level is 2500 mg/day

Calcium Supplements
Recommended for people who cannot
incorporate Ca into their diets
 Not recommended with high-zinc meal
 Calcium carbonate (40% calcium)

– For those with ample stomach acid
– Found in antacids (TUMS)

Calcium citrate (21% calcium)
– Enhances absorption due to acidity content
– Recommended for older adults
Osteoporosis - Video

Break
Osteoporosis
 Calcium
deficiency
 “A pediatric disease with geriatric
consequences”
 Leads to ~1.5 million fractures / year
Slender, inactive women who smoke are
most at risk
 “Less bones”

Osteoporosis
Bone Structure
Bone Growth and Mass
Rapid and continual throughout
adolescence
 Peak bone mass
 Determined by gender, race, familial
pattern, other genetic factors
 Bone loss begins ~age 30
 Women experience increased bone loss
after menopause
 DEXA bone scan

Bone Mineral Density
The Trace Minerals
Needed in much smaller amounts
 Essential for health
 Difficult to study

– Only trace amounts in the body
Animal sources of mineral are generally
better absorbed
 Most Important: Iron (Fe)

Iron
Found in minute amounts in every cell
 18% is absorbed
 Heme iron vs. Nonheme iron

– Heme found in animal products better absorbed
than nonheme
– Meat protein factor may aid in nonheme absorption

Vitamin C enhances absorption (nonheme iron)
Absorption of Iron
 Determined
by body’s need
 Iron storage in intestinal cells
 Absorbed in an acidic environment
 Hindered by phytic acid, oxalic acid,
high fiber, high calcium, polyphenols
Ca
(phytic acid)
Ca
Ca
Ca
Functions of Iron

Hemoglobin in red blood cells
– Transports oxygen and carbon dioxide
– High turnover, high demand for iron
Myoglobin in muscle cells
 Electron transport chain
 Enzyme cofactor
 Immune function
 Drug-detoxification pathway

Iron-Deficient Anemia
Most common form of anemia
 Low levels of hemoglobin and hematocrit
 Insufficient intake and stores
 Reduction in

– Production of red blood cells
– Oxygen-carrying capacity
Iron Deficiency Anemia

Most at risk:
– Infant, toddler, chronic blood loss, vegans,
runners, and women of childbearing years

Signs:
– Paleness, brittle nails, fatigue, poor
temperature control, poor growth
– Fatigue, decreased Immune sys.
Food Sources of Iron
Iron Needs
RDA is 8 mg/day for adult male
 RDA is 18 mg/day for female age 19 to 50
 Daily Value is 18 mg
 Average intake exceeds RDA for men; low
for some women
 Upper Level is 45 mg/day

– Take supplements/ cut them down to size
– More easily digested (see product 65mg tab!)
Iron Toxicity
Serious, especially for children
 Signs:

– Diarrhea, constipation, nausea, abdominal pain
– Causes death due to respiratory collapse (shock)

Hemochromatosis
– Genetic disease (5-10% N. Americans)
– Iron deposit that can lead to organ damage
– May go undetected until organ damage at 50-60
Mineral Functions
What is safe and effective food product that
has nearly all of your vitamins/minerals
that is not a supplement?
Get Your Blood work Tested?

Diet Analysis 2 (Due next wed/Friday) includes
– See website
– Ca
– Fe
– Vit E
– Vit C

For next week, organic foods/ food safety
– Please go see Food Inc. –Nickelodian, Downtown
– 5 pts. For class assignment