Module 10: Minerals Flashcards
define minerals
- inorganic nutrients
- essential in diet
define macrominerals
- present in greater amounts in the body
- intake of over 100mg a day
define microminerals (trace minerals)
- present in lesser amounts in the body
- intake of less than 100mg a day
examples of macrominerals
- calcium
- phosphorous
- potassium
- sulfur
- sodium
- chloride
- magnesium
examples of microminerals
- iron
- copper
- manganese
- iodine
what is the most abundant mineral in the body
calcium
where is calcium in the body
- 99% in skeleton/bones and teeth
- 1% in blood, extracellular fluids, muscle, and other tissues
what regulates blood levels of calcium
- vitamin D
- parathyroid hormone
functions of calcium
- building and maintenance of bone
- muscle contractions
- conduction of nerve impulses
- hormone regulation
- blood clotting
what protein is the structural framework of bones
collagen
what are the primary minerals in bones
- calcium
- phosphorous
what is hydroxyapatite
- crystal in bones that provide bone strength
- made mostly from calcium
- also includes magnesium, sodium, phosphorous, and fluoride
how does calcium affect muscle contractions
calcium binds to protein tryponan to initiate contraction
does muscle contraction require energy
- no
- muscle relaxation requires energy
where is calcium stored
sarcoplasmic reticulum
how does calcium affect nerve impulses
- calcium allows the release of neurotransmitters
- regulates levels of Na+ and K+ ions across the nerve membrane
how often do bones remodel/turnover
constantly breaking down and rebuilding bone
what is the central cause of the loss of structure and density of bone (osteoporosis)
bone loss exceeds bone gain/maintenance
is there a cure for osteoporosis
no
people at what age are more liekly to develop osteoporosis
those over 50
who is at the highest risk for osteoporosis
post-menopausal women
what can you do to prevent osteoporosis
- eat balanced diet with calcium and vitamin D
- exercise regularly
- avoid smoking
- limit alcohol intake
what is the effect of calcium on hormones
magnifies the effect of hormones
describe calcium’s role in hormone regulation
- hormone binds to cell surface
- triggers release of calcium in the cell
- calcium amplifies the hormone’s message (like a second messanger)
why is calcium essential to blood clotting
needed to convert prothrombin to thrombin (which converts fibrinogen to fibrin)
how does calcium affect blood pressure
can help lower blood pressure
define pre-eclampsia
- high blood pressure during pregnancy
- often need in women who are overweight, teenage pregnancies, or women with low calcium levels
what happens when blood calcium levels are low
- increased PTH release
- triggers conversion of vitamin to active form: calcitriol
how does calcitriol and PTH affect calcium level
- increase absorption in intestine
- increase resorption in kidneys
- release calcium from bone
what compounds in foods can decrease absorption of calcium
- phytates
- oxalate
describe phytates
- decrease calcium absorption
- storage form of phosphorous in plant foods
- binds to certain minerals making them unavailable to cells
what minerals do phytates bind to
- calcium
- zinc
- iron
what are the best calcium sources
- dairy products
- sardines/salmon
- broccoli
what is the second most abundant mineral in the body
phosphorous
where is phosphorous in the body
- 85% in bones
- 15% in soft tissues like muscle
how is phosphorous usually found in the body
- with 4 oxygen atoms
- phosphate
what are the functions of phosphorous
- part of bones and teeth
- facilitates enzyme function (turning on and off)
- ATP component
- DNA and RNA component
- phospholipid component
- acid-base balance
which macromineral is found in the smallest amount in the body
magnesium
about how much magnesium does the human body contain
35 g
where is magnesium in the body
- 50% in bone
- 49% in soft tissue
- 1% in body fluids/blood
what are the functions of magnesium
- component of bone (hydroxyapatite)
- maintenance of DNA and RNA integrity
- ATP stabilization
- facilitates muscle relaxation
- cofactor for enzymes
describe how magnesium stabilizes ATP
- ATP exists with 3 negatively charged phosphorous atoms
- Mg 2+ attaches to furthest phosphorous atoms to stabilize the molecule
- Mg 2+ shifts to closest phosphorous atoms when the last phosphorous is ready to be broken off and energy is released
what is the 7th most abundant mineral in the body
sulfur
what is the primary storage site for sulfur in the body
2 amino acids: methionine and cysteine
what causes some people to have curly hair
sulfur in cysteine amino acid bonded to another cysteine
functions of sulfur
- component of amino acids methionine and cysteine
- element in glutathione (antioxidant)
how much iron is stored in the body at once
2-4 g
what is the most common and widespread nutrient deficiency wordlwide
iron deficiency
what is the primary role of iron
in hemoglobin to deliver oxygen to tissues and cells
how many oxygens can one hemoglobin carry
4
how many RBCs does the bone marrow produce every second
2.5 million
define anemia
clinical condition in which hemoglobin levels are low
what lab tests can be used to screen for anemia
- hemoglobin
- hematocrit
- ferritin
- transferrin saturation
what is the hematocrit lab test
percentage of blood that is composed of RBCs
what is the ferritin lab test
identifies ferritin: storage protein for iron
what is the transferrin saturation lab test
identifies the amount of iron transferrin is transporting in the blood
what are common causes of anemia
- low iron intake or absorption
- deficiency of vitamin B6, vitamin B9, or vitamin B12
what are the two forms of iron in our diet
- heme iron
- non-heme iron
define heme iron
- form found in hemoglobin
- only found in meats, fish, and poultry
- most readily absorbed in body
define non-heme iron
- elemental form of iron
- found in plant-based and enriched foods
- less readily absorbed in body
define hemochromatosis
genetic disorder that can cause iron toxicity by inability to regulate iron absorption
is zinc deficiency common worldwide
yes
what are the functions of zinc
stabilize transcription factors for gene expression
what are signs of zinc deficiency
- dwarfism
- poor sexual development
- deformed bones
- poor wound healing
how much zinc is absorbed in the small intestine
40%
what are the functions of copper
- cofactor for enzymes
- absorption, storage, and metabolism of iron
what is selenium content of foods dependent on
selenium content of soil
what is the most important role of selenium
supports body’s antioxidant defense system
what is the only tissue that utilizes iodine
thyroid
what is the primary function of iodine
facilitates production of thyroxine hormone in the thyroid gland
effects of iodine deficiency
goiters
describe goiters
- due to iodine deficiency
- enlarged thyroid gland to try and absorb more iodine
what are the effects of iodine deficiency in pregnant women
cretinism in infants
what is the primary function of fluoride
- strengthens hydroxyapatite in bones
- creates healthy teeth by hardening tooth enamel and preventing tooth decay
define fluorosis
- excessive fluoride intake
- discoloration and mottling of the teeth
what is the primary function of chromium
facilitate glucose uptake by improving the function of the hormone insulin
