Identification mineral 7

The Trace Minerals


Objectives
• After reading Chapter 7 and
class discussion, you will be
able to:
–
–
–
–

Identify trace minerals
Define trace minerals
Define hemoglobin and myoglobin
Describe heme and nonheme iron and its
absorption


Objectives
• Identify food sources of iron
• Identify those at high risk for
iron deficiency
• Identify recommendation for
daily iron intake
• Describe iron toxicity symptoms


The Trace Minerals

The Trace Minerals
• Other Trace Minerals
– Chromium
– Molybdenum
– Manganese

-Selenium
-Nickel
-Silicon

• IRON
–
–
–
–
–

Functions
Absorption
Deficiency/Toxicity
Recommendations
Food sources

-Fluoride
-Copper
-Cobalt


Iron: Functions
• Part of the protein hemoglobin,

which carries oxygen in the blood
• Part of the protein myoglobin in
muscles, which makes oxygen
available for muscle contraction
• Necessary for the utilization of
energy as part of the cells’
metabolic machinery


Iron Absorption


Iron: Heme vs. Nonheme


Factors Enhancing
Nonheme Iron Absorption
• MFP factor
• Vitamin C
• Citric acid from
foods & stomach
• Lactic acid from
foods
• HCl from stomach
• Sugars (including
wine)


Factors Inhibiting
Nonheme Iron Absorption

• Phytates – soy products
• Fibers – whole grains, nuts
• Oxalates – spinach, beets, rhubarb
• Calcium
• Phosphorus
• EDTA (food additive, preservative)
• Tanic acid – tea, coffee


Iron Deficiency
• High risk for iron deficiency
–Women in reproductive years
–Pregnant women
–Infants and young children
–Teenagers
–Blood loss


Iron Deficiency
• How is Fe deficiency measured?
• How does Fe deficiency develop?
• Stages of iron deficiency
– Iron stores diminish
– Transport iron decreases
– Hemoglobin production declines


Deficiency Symptoms
Anemia: weakness, fatigue,
headaches

Impaired work performance and
cognitive function
Impaired immunity
Pale skin, nailbeds, mucous
membranes, and palm creases
Concave nails
Inability to regulate body
temperature
Pica


Toxicity Symptoms
• GI distress
• Iron overload: infections,
fatigue, joint pain, skin
pigmentation, organ damage


Recommendations
• 2001 RDA
– Men: 8 mg/day
– Women (19-50 years): 18 mg/day
– Women (51+ years): 8 mg/day

• Upper level for adults: 45
mg/day


Iron: Food Sources
• Significant sources

– Red meats, fish, poultry, shellfish, eggs
– Legumes, dried fruits
– Enrichment



Non-Food Sources of
Iron
• Contamination
iron from iron
cookware
– More acidic the
food
– Longer cooking
time
– Fe content of
eggs can triple
– Poorly absorbed
• 1-2%
absorbed


Iron Supplements
• Form
– Ferrous sulfate or iron chelate
– Less well absorbed so doses high

• Take between meals or
bedtime
• Take on empty stomach

• Take with liquids
– Not milk, tea, coffee

• Take as a single dose


More On Supplements
• No benefit to taking
supplements with orange juice
(Vitamin C)
– Vitamin C converts insoluble ferric iron in
foods to more soluble form of ferrous iron

• Constipation a common side
effect of iron supplementation
– Increase water intake
– Is there a negative impact to increasing
fiber intake?




Objectives
• After reading Chapter 7 and
class discussion, you will be
able to:
–
–
–
–

Identify trace minerals
Define trace minerals
Define hemoglobin and myoglobin
Describe heme and nonheme iron and its
absorption


Objectives
• Identify food sources of iron
• Identify those at high risk for
iron deficiency
• Estimate recommendation for
daily iron intake
• Describe iron toxicity symptoms