Transcript Water and Minerals

Water and Minerals
Water
 ~60%


of adult body weight is water
% is higher in kids
More muscle, more water
 Changes
in water level can quickly and
dramatically impact weight
Water
 Functions:

Carries nutrients through the body
• Blood and lymph systems

Carries wastes out of the body
• urine


Lubricant and cushion around joints, eyes,
spinal cord, fetus…
Component of secretions
• Mucus, digestive secretions
Water
 Functions


cont’d:
Aids in regulation of body temp.
Needed for many metabolic reactions
• Digestion of proteins, fats and starches

All hydrolysis reactions require the input of water
Water
Maintaining water balance


Goal is to balance water output and input
Water Loss:

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
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
Urine
Feces
Sweat (kids and elderly sweat less)
Exhale moist air
Water
 Water




Input
Water
Other fluids
Water in foods
Water made in metabolism
Water Sources
 Good

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


sources of water
Water
Juice
Sports drinks
Soups
Fruits and vegetables
Water Sources
 Poor


Sources – all are diuretics
Caffeine containing coffee, tea, sodas
Alcohol
Water Intake
 Recommend

text 11-15 cups
 Amount


~8-12 cups/day
needed depends upon:
Calories eaten, more calories, more water
Level of exercise
• Impacts ______ and _______
• Recommend 3 cups water/lb loss sweating

Climate
Blood Volume

Blood volume is regulated by the brain and
kidneys
 When blood volume is low:
 Ion concentrations rise
Decreased Blood Volume
Consequences low blood volume:

Urine production is reduced

Dark yellow urine

Blood vessels narrow to raise blood pressure
 Hypothalamus triggers thirst response


Thirst response ALWAYS lags behind the need for
water
Thirst response diminished in elderly
Dehydration

When a water deficiency develops slowly thirst
usually takes care of it
 When water deficiency occurs quickly
dehydration occurs  VERY SERIOUS
Dehydration
 Symptoms
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of mild dehydration:
Thirsty
Tired and weak
Impaired performance
Impatient and irritable
Flushed skin
Decreased urine output
Dry mouth
Dehydration
 Severe
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Dehydration – SERIOUS
Skin pale and dry
Headache, can’t concentrate
Shallow rapid breathing
Increased heart rate
Dizziness, delirium, collapse
Stop sweating
• Overheat ….VERY SERIOUS
Dehydration and Over-Heating
– athletes and babies die
from this every year (others too)
 Symptoms, in addition to dehydration:
 Over-heating


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Shock
Seizures
Coma
Death
Hyponatremia
 “Water



intoxication”
Fairly rare
Most often occurs with rapid water
consumption combined with heavy sweating
Results in a potentially deadly drop in blood
levels of sodium.
Electrolytes
 Electrolytes
are dissolved ions in body
fluids
 Ion = charged particle

Ions attract water
Electrolytes
 Major
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
Sodium Na+
Chloride Cl -
 Major
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extracellular ions:
Na+
intracellular ion:
Potassium K +
Cl -
K+
Sodium – Na+
 Major
ion outside of cells
 Functions:
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Primary regulator of extracellular fluid volume
Helps maintain acid-base balance
Essential for nerve and muscle contraction
Sodium – Na+
 Absorption
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Absorbed in SI into capillaries
 Recommended
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intake
Minimum 500 mg/day
Maximum 2400 mg/day
• A little more than 1 teaspoon
Sodium – Na+
 Food


sources
Primary sources of sodium are processed
foods, not the salt shaker
Examples of high sodium foods:
Sodium – Na+
 Control
of high blood Na+ levels:
 Goal is to readjust the sodium to water
levels to normal

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Thirst mechanism triggered
Drink more water
Kidneys filter the Na+ out and excrete it in the
urine (if enough water)
Sodium – Na+
 Low

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
blood Na+ levels:
First ion (with Cl-) to be lost with sweating,
bleeding, vomiting, diarrhea….
In response to low Na + levels, kidneys keep
Na+ and excrete more K+
When Na+ levels drop in these ways you need to
replace both the ions and the water
Sodium – Na+
 Can
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raise levels of Na+ and water by:
Ingesting sports drinks
• Drinking dilute juices (add a little salt)
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Combining salt containing foods with fluids
 Salt
pills are never recommended
 Pure water may not be the answer
either….
Sodium – Na+
 Sodium


and Hypertension
High sodium intake is associated w/
hypertension in many people (salt sensitive)
Populations at risk
•
•
•
•
•
African descent
Family or personal history of hypertension
Over 50
Diabetic or obese
Chronic kidney disease
Sodium – Na+
 Lowering

blood pressure
Reduce sodium intake and increase
potassium intake
• Reduce intake of processed foods, increase intake
of fresh foods
• DASH Diet

Lose weight
Sodium – Na+
Na+ intake is associated with
increased calcium excretion
 High

May contribute to osteoporosis
Potassium - K+
 Major
electrolyte inside cells
 Functions:
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Plays a major role in maintaining fluid and
electrolyte balance
Needed for nerve and muscle contraction
Required for a steady heart beat
Plays a role in carb and protein metabolism
Potassium - K+
– occurs in SI  blood
 Recommended intake
 Absorption

Minimum 4700 mg/day
Potassium - K+
 Food

sources
Fresh foods (intact cells)
• Fresh fruits and vegetables
• See page __________

Processing lowers K+ levels and raises Na+
levels
Potassium - K+
 Potassium

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and Health
Low K+ intake is associated with increased
blood pressure
High K+ intake may reduce or help prevent
hypertension
High K+ intake may lower risk of stroke
Potassium - K+
 Potassium


deficiency
Most common electrolyte imbalance
Occurs most often due to excessive losses
not a low intake
 Symptoms


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Muscular weakness (first symptom)
Confusion
Paralysis
Heart failure may occur
Potassium - K+
 Potassium
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Toxicity
Body excretes excess in urine
Any toxicity will come from supplements, not
foods
• Muscle weakness and vomiting
A
shot of potassium into a vein can cause
the heart to STOP = death
Calcium – Ca+2
 Ca
is the most abundant mineral in the
body

99% in bones and teeth as hydroxyapatite
• On a collagen matrix

1% in blood as Ca+2
• Blood level of calcium is tightly controlled
Calcium
 Absorption


Occurs in the SI
Occurs best in an acidic environment
• Best absorption in first section of SI

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To be absorbed the Ca must bind to a Ca
binding protein
Vit D activates the binding protein
Calcium
%
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Absorption
Adults: ~30%
Kids: ~ 50-60%
Pregnancy: ~50%
Calcium – Ca+2
 Functions

Bones
• Key component (along with P) of bone
structure
• Serve as a calcium bank for the blood
Calcium – Ca+2
 Functions



- In Blood
Regulates muscle contraction
Needed for nerve function
Plays a role in blood clotting
Calcium – Ca+2
 Functions



– In Blood
Plays a role in hormone secretion
Activates some enzyme reactions
Activates protein (calmodulin) that helps
regulate blood pressure
Calcium Balance
 Calcium


Balance
Calcium is constantly moving in and out of
bones
Intake must be adequate to replace all Ca
taken out of bones
Calcium Balance
 When


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blood calcium levels go up:
Hormones and vit D promote deposition of Ca
into bones
Key hormone for lowering blood Ca is
calcitonin
Key hormone for raising blood calcium is
parathyroid hormone (PTH)
Calcium Balance
 Calcitonin

– lowers blood Ca
Inhibits vit D activation
• Less Ca absorbed

Prevents Ca reabsorption in kidneys
• More Ca excreted in the urine

Slows breakdown of bones
Calcium Balance
 When

blood calcium levels are low:
Key hormone in raising Ca levels is
parathyroid hormone
• Calcium absorption goes up in SI

assuming Ca in diet and vit D present
• Bones release more Ca into blood
• Kidneys excrete less Ca
Calcium Requirements
 Calcium
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Adequate Intake
Adults 19-50: 1000 mg/day
Adults 51+: 1200 mg/day
Pregnant or lactating: 1000 mg/day
Kids/teens: 1300 mg/day
Calcium Sources
 Food
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Sources
Dairy products – great source of Ca
• Many also contain vitamin D
• Drawback - many are high in fat and cholesterol
Calcium Sources
 Food

Sources
Dark green leafy vegetables
• Fairly good = mustard greens, kale, broccoli
• Not as good = spinach and Swiss chard
 Contain oxalates and phytates which lower the
bioavailability of the Ca
 8 cups of spinach = 1 glass milk
Calcium Sources
 Food

Sources
Nuts and legumes (limited calcium)
• Soy milk is often Ca enriched

Calcium fortified products
• Orange juice
• Soy and rice milk
• Cereals…..
Calcium Sources
 Food

Sources
Other sources
•
•
•
•
Sardines (eat the bones!)
Oysters
Molasses
??? Maple sugar water
Calcium Sources
 Food
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Sources
Asians cook with a stock made by boiling
bones in vinegar
• 1 T = 100 mg Ca

Navajo use juniper ash in cooking
• 1 t = 300 mg Ca (wow)
Calcium
 Acute
low/high blood levels of Ca is
generally vitamin D related

Acute low blood Ca  tetany
• Uncontrolled muscle contraction

Acute high blood Ca  rigor
• Muscles contract and won’t relax
Calcium Deficiency
 Chronic

low calcium intake
Blood calcium levels are maintained at a safe
level
• Bones serve as a source of Ca to keep blood
levels safe
• Overtime this leads to osteoporosis
 “porous bones”
Osteoporosis
Osteoporosis
 Peak
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Impacted by intake of Ca and vitamin D
 Bone
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bone mass is reached by age 30
loss begins after age 30
Bone loss accelerates:
• First 6-8 years after menopause
• Estrogen reduces bone loss
Osteoporosis
 In
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general, lower bone density in:
Women vs. men
Asians, Hispanics, Mexican Americans
Caucasians vs. African American
Smokers
Alcoholics
Low body weight
Over age 50
Maximizing Bone Mass
 Adequate

intake
Especially during peak bone building years
 Weight
bearing exercise
Calcium Supplements
 Good

supplements
Contain no more than 500 mg Ca
• An Intake of over 500 mg reduces absorption
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Also contain vitamin D
Dissolve well
Calcium Supplements
 Good
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supplements include:
Calcium carbonate
Calcium citrate
Calcium gluconate,
Calcium acetate
Calcium chelated amino acids
Others….
Calcium Supplements
 Avoid:
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Bone meal (dolomite)
• May contain heavy metals
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Oyster shell
• Calcium is not well absorbed

Antacids with magnesium or aluminum
Phosphorus
 Second
most abundant mineral in the
body


85% in bones and teeth
Found in ALL cells
Phosphorus
 Functions:
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Structural component of bones and teeth
Part of DNA and RNA
• Need to make new cells
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Part of phospholipids
Part of ATP
Activates many enzymes and B vitamins
Plays a role in acid/base balance
Phosphorus
 Recommended


700 mg/day
Most meet this easily
 Food

Intake:
Sources:
Foods rich in proteins
• Animal proteins are the best sources
• Seeds, legumes

Processed foods (from additives)
Iron
 Trace
mineral
 Other trace minerals include:

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Zinc
Iodine
Selenium
Fluoride
Chromium….
Iron
 Functions:
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Every cell contains iron
• Need to make new cells

Part of enzymes involved in energy
metabolism
Iron
 Functions:

Oxygen carrying component of hemoglobin
• Need to make RBC

Component of the protein myoglobin
• Holds oxygen in muscle cells
Iron
 Most
iron is recycled by the liver and the
spleen

Therefore, needs are low.
 Needs


go up when:
Significant blood loss
During pregnancy
Iron
 Recommended




Intakes:
Adult males: 8 mg/day
Females 19-50: 18 mg/day
Females 51-70+: 8 mg/day
Pregnant: 30 mg/day
 UL:
45 mg/day
Iron
 Sources

of iron – 2 forms
Heme iron – from animal sources
• Absorbed better than nonheme iron

Up to 25% absorbed
• Meat, poultry, fish
 All contain MFP
 MFP enhances iron absorption
Iron
 Nonheme



sources
All plant sources of iron are in the nonheme
form
Animal sources contain both heme and
nonheme iron
Nonheme iron is poorly absorbed
• 2-20% (10% on average)
Iron
 Nonheme





food sources include:
Grains
Legumes
Fortified cereals and grains
Dried fruits
Vegetables
• Many are poor sources due to phytates and
oxalates (same issue as seen w/ calcium)
 Cooking
in iron pans enhances iron
content of food!
Iron
 Iron



Absorption:
Vitamin C enhances Fe absorption
MFP factor raises Fe absorption
Heme sources better absorption
-------------------------------------------------------
Oxalates and phytates decrease absorption
• In dark green leafy vegetables


Tannins in tea and coffee lower absortption
High calcium intake may interfere with
absorption
Iron Deficiency
 Iron


deficiency = reduced iron stores
Not detected with a simple blood test
Occurs often in children
• Affects their ability to be successful in school
• Easily corrected through diet
• Often overlooked

Associated with pica
Iron
 Symptoms

of iron deficiency:
Weak, tired
• low energy
• apathetic



Restless
Irritable
Less productive
Iron
 Iron



Anemia
More serious than iron deficiency
Iron stores depleted
Not enough iron to make hemoglobin
 Symptoms

of Iron Anemia:
All symptoms of Fe deficiency are intensified
Iron Anemia
 Other

symptoms:
Pale
• Can be hard to see in dark skinned individuals




Cold
Headaches
Exhausted, listless
Weak
Anemia
 DO

NOT self diagnose/treat iron anemia
May be a sign of a more serious underlying
health issue
Iron Toxicity
 Often
occurs when a child ingests too
many iron supplements

CAN BE LETHAL
• SEEK IMMEDIATE MEDICAL HELP
Do not call vitamins/medicine candy
Iron Toxicity
 Symptoms





acute iron poisoning:
Nausea, vomiting, diarrhea
Rapid heartbeat
Dizziness
Confusion
Death
Iron Overload
 Iron
overload is more common in males
than females

Deficiency is more common in females
A
common genetic disease called
hemochromatosis results in overabsorption of iron

 iron toxicity
Iron Overload (toxicity)
 Symptoms:

Apathy, lethargy, fatigue
• Same symptoms as in deficiency

Liver damage
• May also become enlarged

Increased infection
• Bacteria love iron

Hair loss
Iron Overload (toxicity)
 Symptoms:



Amenorrhea
Impotence
Increases risk of:
• Diabetes
• Liver cancer
• Heart disease (?)
Anemia
 Many
nutritional deficiencies can lead to
anemia

Nutritional anemia is a HUGE problem
worldwide