ch 9 - minerals Flashcards
macrominerals
found in large amounts
micromineral
found in small amounts (trace)
proper bone formation minerals
calcium, phosphorus, magnesium, fluoride
electrolyte minerals
sodium, potassium, chloride
enzyme related function minerals
iron, zinc, selenium, copper
macrominerals list
calcium, phosphorus, sodium, potassium, chloride, sulfur
intake values for some minerals are ___ ___ for both gender of the same age
the same
mineral balance is maintained by
adjusting absorption and excretion
if mineral storage is high…
absorption decreases
if mineral storage is low…
absorption increases
mechanisms of mineral balance
hormones
altered metabolism
storage capacity
influence of age on mineral absorption
decreases w age
influence of sex on mineral absorption
varies with the mineral
influence of life cycle stage on absorption
growth states generally increase absorption; growth states include infancy and childhood growth, puberty, and pregnancy
influence of genetics on absorption
varies with the individual, absorption could be low, normal, high, or excessive
general and GI health effects on absorption
poor health generally results in poorer absorption
presence of a deficiency state effect on absorption
generally results in inc absorption
amount consumed influence on absorption
in food, higher intakes usually result in greater absorption
presence of other minerals effect on absorption
in food, reduces absorption to a small degree, large amounts found in supplements may reduce absorption of competing minerals to a large degree
presence of food in the GI tract influence on absorption
enhances absorption
compounds found in food influence on absorption
- phytic acid, oxalate, and insoluble fiber are known to inhibit absorption
- soluble fiber enhances absorption
chemical form of the mineral effects on absorption
most minerals have a chemical form that results in greater absorption
food-drug interactions effect on absorption
some medications such as antacids, h2, receptor blockers, and proton pump blockers can increase the pH of the GI tract, which can decrease absorption
iron deficiency without anemia prevelance
estimates for female adolescent and adult athletes are in the 25-36 percent range
osteopenia
subclinical calcium deficiency
low bone mineral density
subclinical zinc deficiency
not likely to be detected in lab tests
iron deficiency anemia
results in fatigue and impairs performance by reducing aerobic capacity and endurance
osteoporosis
clinical calcium deficiency
amenorrhea
low energy availability cessation of menstruation
Calcium bone loss is exacerbated in women when
estrogen production declines; typically associated with menopause.
role of bones in the body: mineraols
maintenance of mineral homeostasis and acid base balance
____ minerals involved in bone formation and healtb
eight
two types of bone
cortical and trabecular
Of the mineral content of bone, 80 to 90 percent consists of
calcium and phosphorus
cortical bone, which is found in the
shafts of the long bones and on the surface of the bones.
trabecular bone is found at
the ends of the long bones and below the surface.
calcitrol
increases calcium absorption in the intestines
osteoblasts
responsible for forming bone
osteoclasts
responsible for resorbing bone
parathyroid hormone
responsible for controlling calcium
at what age is recommended calcium intake the highest
9 and 18
Hemoglobin (heme 5 iron, globin 5 protein) is an _____-containing protein found in the ___ ___ ___ that can bind ____and consists of four polypeptide chains
iron; red blood cells; oxygen
nutritional anemias
- iron deficiency anemia
- vitamin b12 deficiency anemia
- folate deficiency anemia
- anemia due to a deficiency of any nutrient needed for RBC production
nonnutritional anemia
- aplastic anemia
- hemolytic anemia
- sickle cell anemia
The general term anemia refers to a reduced oxygen-carrying capacity and is reflected in a hematocrit of approximately
30 percent
factors that affect iron status in athletes
- sex
- age
- medications
- diet
- exercise induced hemolysis
how does diet affect iron status
- low cal intake
- low or absent animal protein intake
- high intake of iron inhibitors
the immune system is suppressed by
rigorous training, prolonged exercise
the immune system is impaired by
inadequate intake of zinc, magnesium, or selenium
excessive intake of zinc or iron
zinc deficiency causes
decreased production and function of lymphocytes
selenium intake from dietary source
advised to avoid pro-oxidant effects
iron helps to regulate
cytokines
iron and calcium are good predictors of
other mineral intakes
adequate intake of ____ is one of two factors most associated with proper immune system function
protein
t or f: Macrominerals include calcium, phosphorus, and magnesium because they are large in size, whereas microminerals include iron and manganese because they are smaller in size.
false
t or f: To maintain mineral homeostasis, the body can increase or decrease absorption.
true
t or f: Because absorption is low for most minerals, toxicity is not a concern.
false
t or f: Calcium, vitamin D, and protein are important nutritional factors for bone health as well as weight-bearing exercise to achieve peak bone mineral density.
true
t or f: The only way to increase dietary calcium is through dairy product consumption.
false
calcium-fortified foods like…
orange juice and non-dairy milks.
t or f: Individuals with iron deficiency without anemia have low hemoglobin and hematocrit levels, resulting in reduced oxygen transport.
false
Individuals with iron deficiency without anemia (that is, subclinical iron deficiency) have…
normal hemoglobin and hematocrit concentrations, and the effect of this deficiency and subsequent iron supplementation on exercise capacity and performance is less clear.
t or f: Heme iron, which is found in animal foods, has a lower absorption than nonheme iron, found in plant foods and animal tissues.
false
heme iron, which is found in animal foods, has an estimated absorption rate of
15-35%
nonheme iron, which is found in plant foods (as well as animal tissues), has a much lower absorption rate of
2 to 20 percent.
t or f: Zinc, magnesium, and selenium are involved in proper immune system function; however, excessive levels of zinc and iron can impair the immune system.
true
t or f: Consumption of calcium and iron, when obtained from naturally occurring food sources, is a fairly good predictor of the intake of the other minerals.
true
t or f: Although a single supplement may provide more than enough of that particular mineral, there are concerns that a single supplement, especially one containing a high dose, may be detrimental to the absorption of other nutrients.
true
Which of the following is NOT a basic function of minerals?
building body tissue
regulating physiological processes
providing energy for metabolism
maintaining fluid balance
providing energy for metabolism
Which of the following is NOT classified as a macromineral?
calcium
sodium
potassium
iron
iron
A mineral that is under substantial hormonal control is:
zinc.
iron.
calcium.
selenium.
calcium
In the absence of a deficiency, as mineral consumption increases, the amount absorbed:
decreases
The age at which peak bone mineral density occurs is
35 to 60 years
The two factors that best explain the increased risk for osteoporosis in elite female distance runners are
low energy intake and low estrogen.
Why is iron not well absorbed from the intestinal tract?
Overabsorption of iron has potentially harmful physiological effects.
what effect does iron deficiency anemia have on performance?
decline in aerobic capacity
decline in endurance capacity
decline in oxygen utilization
Which of the following is likely true regarding athletes and upper respiratory tract infections (URTIs)?
Prolonged exercise increases risk for URTIs.
What is the potential problem with consuming excess supplemental zinc?
interference with iron absorption
What is the potential problem with mineral supplements that have high bioavailability?
excess absorption
