chapter 12 & 13 the minerals the minerals - an overview inorganic elements retain their chemical...

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

Copyright 2005 Wadsworth Group, a division of Thomson LearningCopyright 2005 Wadsworth Group, a division of Thomson Learning

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


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


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)


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)


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


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


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


Calcium Balance


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


Calcium• Significant sources

– Milk and milk products

– Small fish (canned with bones)

– Tofu (bean curd), greens (broccoli, chard), legumes

– Calcium-fortified products


Calcium• Deficiency symptoms

–Stunted growth in children–Bone loss (osteoporosis) in adults

–Hypertension


Osteoporosis & Calcium8X more common in women due to lower

intakes, smaller body size & less bone mass; loss begins earlier & accelerates after menopause

Osteoporosis & Calcium

• Dietary calcium is the key to prevention

• Other nutrients play a supporting role

• Physical activity and body weight• Smoking and alcohol


Calcium• Toxicity symptoms

– Constipation– Increased risk of urinary stone

formation and kidney dysfunction

– Interference with absorption of other minerals


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


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


Magnesium• 1997 RDA

– 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

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


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


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


Chloride

• Deficiency symptoms– Do not occur under normal

circumstances

• Toxicity symptom– Vomiting


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

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