Transcript Minerals

Chapter 12 & 13
THE MINERALS
The Minerals - An Overview
• Inorganic elements
• Retain their chemical identity in the
body
• Can be toxic if taken in excess
• Variable bioavailability
–Binders that prevent absorption
•Phytates
•Oxalates
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The Minerals
Sodium
• Chief functions in the body
-Principal extracellular cation
–Maintains normal fluid and
electrolyte balance
–Assists in nerve impulse
transmission and muscle
contraction
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Sodium
• 1989 estimated minimum requirement for
adults: 500 mg/day
• Daily Value (used on food labels): 2400
mg/day
• Sources:
-Table salt: 1 tsp. NaCl=~2 gm Na
-Large amounts in processed or cured
foods
-Soy sauce
-Moderate amounts in meats, milks,
breads, and vegetables
Sodium
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Sodium
• Deficiency symptoms
– Muscle cramps, mental apathy, loss of
appetite
• Toxicity symptoms
– Edema, acute hypertension
• High intake may contribute to high
blood pressure
• High intake also associated with
calcium/bone loss (osteoporosis)
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Potassium
• Principal intracellular cation
• Chief functions in the body
– Maintains normal fluid and electrolyte
balance
– Regulates acid-base balance
– Facilitates many reactions
– Supports cell integrity
– Assists in nerve impulse transmission
and muscle contractions (especially
heart)
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Potassium
• 1989 estimated
minimum requirement
for adults:2000
mg/day
• Recommendation:
3500 mg/day
• Significant sources
– All whole foods
– Meats, milks, fruits,
vegetables, grains,
legumes
– Salt substitutes
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Copyright 2005 Wadsworth Group, a division of Thomson Learning
Potassium
• Deficiency-usually results from
excessive losses due to diabetic
acidosis, dehydration, prolonged
N/V, certain medications (diuretics,
cathartics, steroids)
• Symptoms:
– Muscular weakness
– Paralysis
– Confusion
– Associated with high blood pressure
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Potassium
• Toxicity-unlikely unless supplement
abuse or kidney disease
• Symptoms
– Muscular weakness
– Vomiting
– If given into a vein, can stop the heart
Calcium
• Most abundant mineral in the body
• Chief functions in the body
– Mineralization of bones and teeth
– Involved in muscle contraction and
relaxation, nerve functioning, blood
clotting
– Blood pressure, immune defenses
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Calcium Balance
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Calcium
• 1997 adequate intake (AI)
– Adults 19-50 years: 1000 mg/day
– Adults 51 & older: 1200 mg/day
-Postmenopausal women:
1500 mg/day
• Upper level for adults:
2500 mg/day
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Calcium
• Significant sources
– Milk and milk
products
– Small fish (canned
with bones)
– Tofu (bean curd),
greens (broccoli,
chard), legumes
– Calcium-fortified
products
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Calcium
• Deficiency symptoms
–Stunted growth in children
–Bone loss (osteoporosis) in
adults
–Hypertension
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Osteoporosis & Calcium
8X more common in women due to lower
intakes, smaller body size & less bone
mass; loss begins earlier & accelerates
after menopause
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Osteoporosis & Calcium
• Dietary calcium is the key to
prevention
• Other nutrients play a supporting
role
• Physical activity and body weight
• Smoking and alcohol
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Copyright 2005 Wadsworth Group, a division of Thomson Learning
Calcium
• Toxicity symptoms
–Constipation
–Increased risk of urinary stone
formation and kidney
dysfunction
–Interference with absorption of
other minerals
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Phosphorus
• 2nd most abundant mineral in the body
• Chief functions in the body:
– Mineralization of bones and teeth
– Part of every cell
– Important in genetic material, part of
phospholipids
– Used in energy metabolism
– Used in buffer systems that maintain
acid-base balance
– Phospholipids – transport of fats
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Phosphorous
• 1997 RDA for adults:
700 mg/day
• Upper level for adults (19-70
years): 4000 mg/day
• Significant sources
–All animal tissues (meat, fish,
poultry, eggs, milk), whole grains,
legumes
Phosphorous
• Deficiency symptoms
–Muscular weakness, bone pain
• Toxicity symptoms
–Calcification of nonskeletal tissues,
particularly the kidneys
Magnesium
• Chief functions in the body
– Bone mineralization
– Component of teeth
– Critical to enzymes for energy/protein
metabolism
– Muscle relaxation/contraction
– Nerve impulse transmission
– Building of protein
– Functioning of immune system
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• 1997 RDA
Magnesium
– Men (19-30 years): 400 mg/day
– Women (19-30 years): 310 mg/day
• Upper level for adults: 350 mg nonfood
magnesium/day
• Significant sources
–
–
–
–
–
–
Nuts, legumes
Whole grains
Dark green leafy vegetables
Seafood
Chocolate, cocoa
“Hard” water
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Magnesium
• Deficiency can result from vomiting &
diarrhea, alcoholism, protein
malnutrition, diuretic use, renal failure
• Deficiency symptoms
– Weakness
– Confusion
– If extreme, convulsions, tetany (rigidity
especially of eye and face muscles),
hallucinations, and difficulty in swallowing
– In children, growth failure
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Magnesium
• Toxicity: possible in elderly who may
abuse Mg-containing
laxatives & antacids
• Toxicity symptoms
– From nonfood sources only
– Diarrhea, alkalosis, dehydration
Chloride
• Chlorine (Cl2) vs. chloride ion (Cl-)
• Roles in body
–Principal extracellular anion
• Chief functions in the body
– Maintains normal fluid, electrolyte, and
acid-base balance
– Part of hydrochloric acid found in the
stomach, necessary for proper digestion
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Chloride
• 1989 estimated minimum
requirement for adults:
750 mg/day (no RDA established)
• Significant sources
– Table salt, soy sauce
– Moderate amounts in meats, milks,
eggs
– Large amounts in processed foods
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Chloride
• Deficiency symptoms
– Do not occur under normal
circumstances
• Toxicity symptom
– Vomiting
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Sulfur
• Chief functions in the body:
-Occurs as part of thiamin & certain
amino acids
-Role in protein structure
-Concentrated in skin, hair, & nails
• Sources: all protein foods
• Deficiency: only in severe protein
deficiency