Minerals
Chapter 7
What are minerals?
•
•
•
•
Inorganic molecules
Essential for human survival
No caloric value
Not degraded by cooking or digestion
Mineral Classification
Major Minerals
• Needed in amounts
>100 mg
• Common examples:
– Sodium
– Potassium
– Calcium
Trace Minerals
• Needed in amounts
<100 mg
• Common examples:
– Iron
– Zinc
– Chromium
Major Mineral: Calcium
• Most abundant mineral
• Functions:
– Blood clotting
– Muscle contraction
– Nerve transmission
– Bone formation
– Teeth formation
– Disease prevention
– Weight management
• AI:
– 1,000 mg/day
– UL = 2,500 mg/day
Source: USDA
Major Mineral: Calcium
(continued)
• Recommendations are
not being met
• Diets can negatively
affect absorption
•
•
•
•
•
Oxalates
Fiber
Phosphorus
Sodium
Animal Protein
Source: USDA
Major Mineral: Calcium
(continued
• Supplementation
–
–
–
–
–
Restrictive diets
Not more than >500 mg
Taken with food
Do not take with other supplements
Watch the type of calcium
Major Mineral: Phosphorus
• Functions:
– Bone and tooth
formation
– Cell membrane
formation
– Enzyme activity+
– Part of ATP and CP
Source: USDA
Major Mineral: Phosphorus
(continued)
• Intake usually well
above RDA
• Concern for
excessive intakes
• Decrease calcium
• Increased risk for
osteoporosis
Source: USDA
Major Mineral: Magnesium
• Functions:
– Bone formation
– Blood clotting
– Regulation of blood
pressure
– Enzyme activity
Source: USDA
Major Mineral: Sodium
• Functions:
– Major electrolyte
– Nerve impulse
transmission
– Muscle contraction
– Regulation of blood
pressure
• RDA:
– 1,500 mg/day (needs
only 500 mg)
– UL 2,300 mg/day
Photo © Photodisc
Major Mineral: Sodium
(continued)
• Athletes need sodium
• ¼ of Adults have HBP
+
(endurance) Na aids in the
• >50% over 60 have HBP
absorption of glucose
• May need supplements for • 1tsp of Salt = 2,300 mg
activities longer than 4
hours
Major Mineral: Chloride
• Functions:
– Major electrolyte
– Nerve impulse
transmission
– Aids digestion (HCl)
(harmful bacteria)
– Fluid balance
– NaCl
• AI:
– 2,300 mg/day
– UL = 3,500 mg/day
Photo © Photodisc
Major Mineral: Potassium
• Functions:
– Major electrolyte
– Nerve impulse transmission
– Muscle contraction
– Blood pressure regulation
– Fluid balance
• RDA:
– 4,700 mg/day
Photo © Digital Stock
Major Mineral: Potassium
(continued)
• Large gap in RDA
and the typical
American diet
• Taking large doses
in the form of
supplements can
lead to heart attack
(>18,000 mg)
Photo © Digital Stock
Major Mineral: Sulfur
• Functions:
– Part of hundreds of sulfur containing
compounds in the body.
• No RDA, EAR, or AI has been established.
Trace Mineral: Iron
Most Common Nutritional Deficiency
• Functions:
–
–
–
–
Oxygen transport and utilization
Component part of hemoglobin and myoglobin
Immune function
Brain development
• RDA:
– 18 mg/day (females aged 19 to 50)
– 8 mg/day (all others)
Why are athletes at increased risk for
iron deficiencies?
• Low dietary intake (Supplements are
suggested)
– Vegetarians beware
– Female athletes
– Distance runners
• Increased demand for hemoglobin and
myoglobin due to training and sport
• Types of foods
• Type of sport
• Loss through sweat
Trace Mineral: Iron
• Signs of deficiency:
– Deficiencies common
– Anemia
– Fatigue
– Cold intolerance
– Decreased performance
• Symptoms of toxicity:
– Nausea, diarrhea
– Rapid heart beat
– Dizziness
If left untreated will cause rapid
death
• UL = 45 mg/day
• Common in children
Source: USDA
Trace Mineral: Iron
• Several types of anemia (table 7-2)
–
–
–
–
Iron
B6
B12
Folate
Trace Mineral: Zinc
• Functions:
– Cofactor in over 200 enzymatic systems
• Wound healing
• Growth and maintenance
• Protein synthesis
• CNS, GI, and reproductive systems
Trace Mineral: Chromium
• Functions:
– Enhances function of insulin
– Decreases cellular insulin resistance
Trace Mineral: Chromium
(continued)
• Those following a very strict diet for
extended periods of time should be
monitored for adequate chromium intakes
• Supplements at high levels over a period of
time could interfere with the iron and zinc
absorption
• Many weight loss seekers were (are)
disappointed
Trace Mineral: Fluoride
• Functions:
– Bone and tooth
mineralization
– Prevents dental caries
– Ligament/tendon
strength
• AI:
– 3 to 4 mg/day
Trace Mineral: Fluoride
• Water - .7 – 2 mg/liter
• Not all communities have
fluorinated water
• Caution with bottle water
Trace Mineral: Copper
• Functions:
– Iron metabolism
– Antioxidant
cofactor
– Enzyme cofactor in
tissue growth and
energy metabolism
Source: USDA
Trace Mineral: Copper
(continued)
• Zinc and iron can interfere with the
absorption
• Menkes Syndrome – deficiency
• Wilson’s Disease - toxicity
Trace Mineral: Manganese
• Functions:
– Enzyme cofactor
• Metabolism
• Antioxidant
• Tissue growth
Source: USDA
Trace Mineral: Manganese
(continued)
• One of the few minerals or vitamins
that seem to absorbed better with
supplements
• Excessive iron, phosphorus and
calcium may inhibit the absorption
Trace Mineral: Iodine
• Functions:
– Assists in synthesis
of thyroid
hormones
• RDA:
– 150 µg/day
Source: USDA
Trace Mineral: Iodine
(continued)
• First trace mineral to be fortified (salt)
Trace Mineral: Molybdenum
• Functions:
– Antioxidant cofactor
– Enzyme cofactor in metabolism of amino
acids containing sulfur
Trace Mineral: Molybdenum
(continued)
• Toxicities and deficiencies are very rare
Trace Mineral: Selenium
• Functions:
– Component of many proteins in body
– Enzyme cofactor
• Immune function
• Thyroid function
• Antioxidant
• RDA:
– 55 µg/day
Trace Mineral: Selenium
(continued)
• Essential nutrient
(1979)
• Keshan Disease
• Along with Vitamin
E as an antioxidant
Source: USDA
Other Trace Minerals