Chapter 10: Micromineral (Iron) Flashcards
an adult male contains _____ mg of iron per kg body wt
40-50 mg
adult female contains _____ mg of iron per kg body wt
30-50 mg
more than 2/3 of the body iron is in the form of functional iron (perform specific role), which is bound within the _____ (Hb) molecule or within the _____ in the muscle tissues
hemoglobin and myoglobin
_____ (storage form) is found in the liver, spleen, and bone marrow
non-functional iron
non-functional iron (storage form) is found in the (3)
liver, spleen, and bone marrow
iron - functions
plays a key role in _____ and _____
oxygen transport and cellular respiration
iron - functions
as part of the Hb and myoglobin, iron bind to oxygen and transports o2 through the _____ (in Hb) or stores o2 within the _____
blood, muscles
iron - functions
as part of Hb, it is involved in the formation of _____ (RBCs)
red blood cells
iron - functions
a co-factor of non-heme enzymes and other chon
-
iron - absorption and metabolism
available to the body either in the _____ form (present only in animal products) or _____ form (iron in plants)
heme form
non-heme form
heme form is available in
animal products
non-heme form is available in
iron in plants
iron - absorption and metabolism
absorption occurs primarily in the _____ (2)
duodenum and jejunum
iron - absorption and metabolism
variety of factors influence iron absorption:
the higher the intake of iron, the lower the percentage of iron absorbed
size of dose
iron - absorption and metabolism
variety of factors influence iron absorption:
those deficient in iron absorb more of the mineral
body needs
iron - absorption and metabolism
variety of factors influence iron absorption:
ferrous form (Fe 2+) is better than ferric form (Fe 3+)
forms of iron
which iron is better?
in ferrous form (Fe 2+) or in ferric form (Fe 3+)
ferrous form (Fe 2+)
iron - factors enhancing the absorption of non-heme iron
increased acidity
animal tissue chon
-
factors inhibiting the absorption of non-heme iron:
-low gastric acidity
-high dietary calcium and phosphorous intakes
-high manganese intake
-dietary fiber
-certain chons
-phytates and oxalates
-polyphenols
-
iron - absorption and metabolism
after absorption, iron is carried to the blood bound to the _____
protein transferrin
iron - absorption and metabolism
iron is absorbed in the _____ in the form of ferritin and hemosiderin
liver
iron - absorption and metabolism
iron is absorbed in the liver in the form of _____
ferritin and hemosiderin
iron - absorption and metabolism
90% of iron is released in the breakdown of cells
-
iron - interrelationship with other nutrients
enhances iron absorption by acting as a reducing agent and forms a chelate with non-heme ferric iron at a lower pH
the chelate remains soluble in the small intestine, thus improving intestinal absorption of non-heme iron
vitamin c
iron - interrelationship with other nutrients
vitamin c enhances iron absorption by acting as a reducing agent and forms a _____ with non-heme ferric iron at a lower pH
the chelate remains soluble in the small intestine, thus improving intestinal absorption of non-heme iron
chelate
the chelate remains _____ in the small intestine, thus _____ intestinal absorption of non-heme iron
soluble; improving
iron - deficiency
results in low Hb stores, fatigue, weakness, pallor, poor resistance to cold temperature, and apathy
microcytic, hypochromic anemia
iron - toxicity
a condition with large deposits of iron deposit, hemosiderin in the liver
hemosiderosis/siderosis
iron - toxicity
a genetic disorder that enhances iron absorption
hemochromatosis
iron - recommended intake
this would cover the _____ losses plus growth in children and _____ losses for women of reproductive age
basal losses; menstrual losses
iron - recommended intake
for infants: iron provided by breastmilk is adequate to meet the iron needs of infants exclusively fed human milk from birth to 6 months of age
-
iron - recommended intake
the consumption of _____ and _____ foods is recommended for women from adolescence onwards
iron-rich and iron-fortified foods
iron - recommended intake
_____ recommended to meet the needs of pregnant and lactating women
iron supplementation
iron - recommended intake
the estimated requirement during the 1st trimester of pregnancy and the 1st 6 months of lactation are _____ than the requirement for menstruating non-pregnant and non-lactating to allow for build-up of iron stores during these periods
lower
iron - recommended intake
for adults (19 - >70 y/o) male
12 mg
iron - recommended intake
for adults (19-49 y/o) female
28 mg with supplements and intake of iron-rich and iron-fortified foods
iron - recommended intake
for adults (50 - >70 y/o) female
10 mg
iron - recommended intake
for pregnant
(+10)
with supplements and intake of iron-rich and iron-fortified foods
iron - recommended intake
for lactating
+2
