chapter 15 - trace minerals Flashcards
trace mineral definition
required in amounts under 100mg
iron types
- heme: a protein, found in meat
- non-heme: found in both meat & plants
heme iron absorption
easily absorbed
transferrin transports iron into bloodstream
non-heme iron absorption
only absorbed when body LACKS iron
converted to heme iron before being picked up by transferrin
ferritin
transport protein that helps the body absorb iron by transporting it to the bloodstream
it is made OUT OF iron only when the body has enough iron
when ferritin is being made, it blocks more iron from being absorbed
MOST iron in body = hemoglobin, NOT ferritin
iron bioavailability
heme = readily absorbed
non-heme = limited absorption
- enhanced by MFP factor and Vit C
- inhibited by phytates and tannins
things that enhance iron absorption
- vitamin C
- heme iron
- leavening bread
- fermentation
- soaking beans or grains
- cast-iron pans
things that inhibit iron absorption
- high calcium with iron-containing food
- meds that reduce stomach acidity (antacids)
- oxalic acid (from foods like spinach)
- phytic acid (from foods like whole grains)
- soy protein (from foods like tofu)
- polyphenols (from tea)
ferritin
major storage form of iron
we use ferritin serum concentrations to assess iron status
stored in the liver, spleen, & bone marrow
transferrin
protein that transports iron to the bloodstream
anemia definition
condition where number of red blood cells are reduced/altered so they can’t carry enough oxygen
most common health problem in US & the world
anemia causes
blood loss
chronic low intake of iron OR low intake during critical periods (puberty, pregnancy)
populations at risk: females, vegans
microcytic anemia
anemia that comes from iron deficiency: comes from lack of red blood cells OR red blood cells don’t have enough hemoglobin
microcytic anemia consequences
alters:
1. normal growth
2. behavior
3. immune system function
4. energy metabolism
microcytic anemia symptoms
- fatigue/weakness
- shortness of breath
- dizziness/headache
- coldness in hands & feet
- pale skin
hereditary hemochromatosis
genetic defect that makes people absorb too much iron
symptoms = fatigue, lack of energy, abdominal pain
zinc sources
meat (pork, beef, lamb)
seafood
enriched/fortified cereal
dairy
legumes
things that enhance zinc absorption
low zinc intake/zinc deficiency
certain amino acids
things that inhibit zinc absorption
excessive intake
phytic acid/fiber (from whole grains)
high nonheme iron intake
zinc deficiency consequences
delayed growth
delayed sex organ maturation
impaired vit A function
impaired immune function
zinc toxicity
symptoms/consequences =
diarrhea/cramps
nausea/vomiting
depressed immune system
interference with copper absorption and metabolism
iodine functions
component of thyroid hormones - maintains thyroid hormone metabolism (BMR)
thyroid hormone functions
regulates basal energy expenditure & macronutrient metabolism
regulates brain & nervous system development
iodine sources
iodized salt
animal products
seaweed
endemic goiter
enlarged thyroid caused by iodine deficiency
endemic cretinism
impaired development caused by iodine deficiency
hypothyroidism
low basal metabolic rate
caused by iodine deficiency
fluoride unique function
development of teeth & bone
fluoride sources
tea
seafood
fluoridated drinking water
seaweed
fluoride deficiency
susceptibility to dental caries (cavities)
leads to nutritional problems due to issues with chewing
fluorosis
fluoride toxicity - causes dark spots on teeth
selenium unique function
converts thyroid hormone T4 to T3
these hormones help maintain BMR
selenium sources
meat, eggs
wheat germ
Brazil nuts & sunflower seeds
selenium deficiency
changes in thyroid hormone metabolism
increased cancer risk
Keshan disease
selenosis
selenium toxicity - impairs sulfur & protein metabolism
symptoms: nausea, diarrhea, hair loss, fatigue
malignant cells
cancerous cells:
divide repeatedly & frequently
don’t die
don’t perform their specialized function
cancer
group of chronic diseases characterized by cells that have MUTATED
cancer development & progression
- repeated damage to an abnormal cell causes it to DIVIDE uncontrollably
- abnormal (malignant) cells form a TUMOR
- one malignant cell in the tumor becomes INVASIVE
- malignant cells BREAK AWAY from tumor and enter circulatory or lymphatic systems (metastasize)
- malignant cells form NEW tumors in other parts of the body
- tumor stimulates development of its own blood supply, DEPRIVING the rest of the body of nourishment
cancer risk factors
- aging
- genes/family history
- tobacco use
- radiation exposure
- exposure to certain environmental substances
- certain viral or bacterial infections
- elevated levels of certain hormones
- consuming alcohol or certain foods
- physical inactivity and excess body fat
role of diet in cancer development
substances in food/beverages that promote cancer:
1. alcohol
2. certain molds that grow on nuts/grains
3. processed/red meats
4. fried, grilled, broiled meats
also: excessive energy intake
cancer prevention guidelines
- eat a variety of veg, fruit, & whole grains
- don’t rely on supplements
- maintain a healthy weight & be active
- don’t drink much alcohol
- eat low-salt foods
- avoid sugary drinks/processed meat
- limit red meat intake
- only breastfeed for 6 months
iron functions
- oxygen transport: hemoglobin & myoglobin
- energy metabolism
- cell division (DNA production)
- immune system (makes white blood cells)
- nervous system (maintains myelin sheath covering certain nerve cells)
zinc functions
- cofactor for over 300 enzymes
- heme synthesis
- DNA & RNA synthesis
- growth & development, reproduction
- bone formation
- immune function
- antioxidant
antioxidant trace minerals
zinc & selenium
selenium SPARES Vit E
anemia types
pernicious anemia = Vit B12 deficiency
macrocytic anemia = Vit B12 & folate deficiency
microcytic anemia = iron deficiency
tumor types
invasive = spread to other parts of body
malignant = cancerous
