Chapter 11 12 Flashcards
classifying minerals
- essential
- need small amounts
- major and trace minerals
understanding minerls
- inorganic (no c)
- involved in body structure and regulation
found in plant and animal foods - not destroyed by extreme conditions
calcium - bone
- synthesis and maintemance
- constant turnover (bone formation and resorption)
- storage place for calcium
importance of calcium and vit d
- prevent osteoporosis
- youth and adolescent intake is critical
osteoporosis
- bones break with low energy
- poor bone density and structure
- due to lack of bone accrual during growth or bone loss with age or meds
nutrients that benefit bone health
- calcium - hydroxyapatite formation
- vitamin d - preserves Ca
- protein - important for strong collagen
- magnesium and vit K
calcium functions
- bone structure
- blood clotting
- nerve impulse transmission
- muscle contraction
calcium regulations
- homeostatic control in blood
- hypocalcemia results in raiding bone for Ca
regulation of blood calcium
- high blood calcium: thyroid gland –> calcitonin –> inhibits calcium release from bone –> normal
- low blood calcium: parathyroid gland –> parathyroid hormone –> stimulates calcium release by bone, calcium reabsorbed by kidney, activates vit d –> increases intestinal calcium absorption –> normal
calcium dri
- adolescent: 1300mg
- adults <50: 1000mg
- adults >51: 1200mg
fractional ca absorption
- inversely proportional to Ca status
- if you have good Ca you will absorb less
factors that increase risk of low bone strength
- high sodium intake
- phytate (interferes w absorption)
- oxalate (interferes with absorption)
- fluoride
food sources of calcium
- milk and dairy
- fortified foods
- fish bones
- green veg
- tofu
- supplements
calcium requirements are controversial
- is loading through exercise more important
- does harm occur if a growing teen consumes less than 1300mg per day
- if youre loading your bones is a low Ca diet ok
- high impact moves good
magnesium
- part of reactions: cardiac function, enegy metabolism
- stored in bone
- 50% consumed absorbed
- high in plant based foods
magnesium deficiency
- causes: intake, dieting, high meat low veg
- malabsorption
- excessive excretion
- hard to detect bc mg is in bone
- method of detection: serum magnesium
- low serium levels have little correlation with total mg levels
iron
- oxygen transport: heme part of hemoglobin and myogloin
- cofactor for enzymes
- needed for normal brain
- needed for immune function
iron food sources
- red meat
- liver
- seafood
iron deficiency
- causes anemia; fatigue
- babies: milk low in Fe
- blood loss, parasites, poor absorption, low intake
iron absorption
- absorb 1-50%
- usually absorb 5-15%
- absrob more with vitc and less with Ca
- aging: stomach acid decreases so need more fe
iron toxicity
- children: due to poisoning
- adults: hemochromatosis - hereditary, liver disease, blood letting reduces toxic fe
iron deficency and dental caries
- iron supplements reduce dental caries in rats
- fe deficiency: saliva promotes colonization of s mutans
- low serum iron in kids with high early childhood dental caries
zinc functions
- cofactor for enzymes
- gene regulation
- immune health
zinc food sources
- red meats, seafood
zinc deficiency
- poor growth, delayed development, infections, skin lesions
zinc toxicity
- can cause copper deficiency
- competitive with some other divalent cations
- high amounts tolerated
zinc veg
- vegetarians need 50% more
zinc rda, ul, toxicity
men: 11mg, women: 8mg
- ul: 40mg
- toxicity: 2000-4000mg
zinc needed for
- wound healing
- taste
- vitamin a metabolism
selenium absorption
- enhanced by vitamin a, c, e
- absorption decreased by phytate
selenium deficiency
- results in increased susceptibilyt to some infections
- musclular discomfort and weakness
selenium toxicity
- brittle hair and nails, fatigue
- ul: 400g
- may develop keshan disease
selenium functions
- part of antioxidant enzyme
- works with vit e
- important in thyroid metabolism, immune function
se food sources
- brazil nuts, oysters, organs, fish, seafood, grains
selenium supplement
- se and vit e taken together
- early testing: se supplements increased risk of prostate cancer
- vit e was factor that most increased risk of prostate cancer, se had no portestive effect
- no correlation wiht se and cancer
iodine funcitons
- thyroid hormone production
- temp regulation
- regulation of metabolic rate
iodine food sources
- saltwater seafood
- iodized salt, dairy products
- seaweed
- i containing disinfectants
goitrogens
- substances that interfere with iodine uptake in thyroid gland
- decreased production of thyroid hormones
- cmmunicates to pituatry to release thyroid stimulating hormine
- leads to goiter
- cabbage, brussle sprouts, turips, radishes, kale etc
low iodine
- low metabolic rate, fatigue, weight gain
- goiter, enlargement of thyroid hormone
- maternal deficiency can result in cretinism - mental retardation
iodine excess and rda
- goiter
- rda: 150 ug for adults, 220 during pregnancy, 290 for breastfeeding women
- ul: 1100
copper functions
- melanin, collagen, elastin production
- immune function
- antioxidant enzyme systems
- iron metabolism
copper foo sources
- beef liver, shellfish, nuts, legumes
coper deficiency or toxicity
- uncommon
fluoride functions
- tooth structure, decreases dental caries
- makes bones more dense but not stronger
fluoride food sources
- fluoridated water
fluoride excess
- can cause fluorosis: discolouration of teeth, kidney disorder
chromium functions
- glucose metabolism
chromium foo sources
- mushrooms, chocolate, nuts, whole grains, asparagus, prunes
chromium deficnecy and toxicity
- deficiency: long term parenteral feeding
toxicity: airporne sources
toxic minerals: arsenic
- causes cancer
- water sources common in canada - high on south shore
- food sourceS: high levels in rice and seaweed
toxic minerals: cadmium
- mostly food sources
- induces apoptosis in human osteoblast
- avoid kidney and liver from moose
toxic minerals: lead
- often airborne sources
- high in canadian drinking water
