lecture 7: minerals Flashcards
major minerals
amounts exceeding 5g in the body
- calcium, phosphorus, potassium, sulfur, sodium, chloride, magnesium
(SNaP CaKCl Mg)
trace minerals
less than 5 grams in the body
- iodine, iron, zinc, selenium, fluoride, chromium, copper, other
calcium roles
integral part of bone structure
bone serves as calcium reserve
regulated by hormones
- other 1% is in body fluids: muscle contraction/relaxation, nerve function, blood clotting
bone formation calcium
hydroxyapatite: calcium + phosphorus = Ca3(PO4)2, add collagen
fluorapatite: displaces “hydroxy” part; fluoride makes bone stronger, resists resorption
calcium absorption
increased when calcium is needed
- amount absorbed in intestine increases
bone loss
happens around 25-30, 10 yrs after peak bone mass/height
osteoporosis
pediatric disease with gerontological effects
how to protect against bone loss
diet rich in calcium in early life
calcium sources
primarily milk and alternatives or fortified beverages
broccoli, leafy greens, legumes
avg canadian does not meet recommendations
calcium deficiency
adult bone loss - osteoporosis
in children - stunted growth, weak bones
calcium toxicity
quite rare
- constipation and kidney stones
phosphorous
2nd most abundant, associated w bones and teeth
phosphorus roles
maintain acid-base balance
part of DNA/RNA
part of metabolism - P in NADP
assists enzymes, vitamins in extracting energy = ATP
part of the phospholipids
phosphorus deficiency
doesn’t rly happen, easily met
phosphorus toxicity
calcification of soft tissues
phosphorus sources
animal proteins are best source
found in cola drinks
magnesium
50% bones, 1% fluid, rest in muscles, heart, liver, soft tissues
blood mg can b reg by taking it from bones or kidney reabsorption
magnesium roles
helps enzymes function
metabolism
muscle function
bone mineralization and resistance to tooth decay
magnesium deficiency
may occur from inadequate intake, vomiting, diarrhea, alcoholism, protein energy malnutrition
or
hospital clients on TPN and poor diets
magnesium sympt
muscle weakness
CVD, heart attack, HTN
symp rare tho inakes often below recommended
magnesium toxicity
may cause diarrhea, acid base imbalance
rare but fatal only w high intakes from supplements, mg salts, laxatives/antacids
magnesium sources
easily washes/peels away from foods in processing
totally unprocessed or slightly processed
vegetarian protein: legumes, nuts
whole grains, dark green veggies, seafood, chocolate
sodium role
fluid/electrolyte balance
acid-base balance
muscle contraction, nerve transmission
sodium deficiency
rare since foods are salty
can result from low sodium, kidney disease, heart failure diets
endurance athletes
hyponatremia: low blood sodium, headache, confusion, stupor, seizures, coma
sodium body maintenance
- absorbed freely byb body and excess excreted by kidneys into urine
- small amount lost in sweat
- amount excreted in day = amount digested per day
RDA intakes for sodium**
AI (adequate intake): 1500mg (age 19-50)
(UL) Tolerable upper intake level: 2300mg
ppl eat more than UL approx 3400mg/day
gen from processed food, soy sauce, MSG, flavouring, bread (surprisingly)
sodium sources
- junk food, bread, processed food, tomato dishes, soups, pasta, cheese (except swiss), meat dishes, sauces (anything seasoned)
75% processed food
blood pressure sodium
- high sodium associated w higher HTN, CVD, cerebral hemorrhage rates
- more salt = higher bp and risk for CV diseases
- some ppl sodium sensitive
reasons to reduce salt
- old ppl w/o HTN can die of stroke
- lowering intake can lower bp to reduce risk of stroke
- can cause congestive heart failure or make kidney problems worse
- potentially cause stomach cancer
potassium
principle +’ve charged ion inside body’s cells
potassium roles
maintenance of:
fluid balance
electrolyte balance
heartbeat
potassium deficiency
reasonable diets provide enough K to prevent dangerously low k
- heart failure from: fasting, severe diarrhea, eating disorders, etc
- can make HTN worse
normal intake is little over 50% of AI
potassium sources
- fresh, whole foods, fruits - processing reduces it
- OJ, bananas, potatoes, tomatoes, avocados, strawberries, spinach, cantaloupes
AVOID if u have chronic kidney disease
potassium toxicity
- SAFE unless u have chronic kidney disease
- if injected to vein stops heart
- OTC KCI pills - don’t take unless doc tells u
chloride
major neg ion in body
chloride role
acid base balance
electrolyte balance
component of HCI
chloride sources
salt; added and naturally occuring
chloride deficiency
not possible
sulfur roles
synthesis of compounds w s
- amino acids w S - cysteine, methionine***
- disulfide bonds w cysteine
- antioxidants
- thiamin, biotin
sulfur sources
protein containing food (in amino acids)
sulfur deficiencies
unknown
sulphur toxicity
diarrhea, not important
iodine
has been added to table salt to meet intakes
iodine roles
require thyroxine (hormone) made by thyroid gland to reg metabolism
iodine deficiencies
- enlarged thyroid - GOITRE***
- severe deficiency during preg - CRETINISM***; retardation
- sluggishness
- weight-gain
iodine toxicity
enlarged thyroid gland but decreased thyroid activity
iodine sources
- iodized table salt
- seafood
- depends on soil which has 1/2 day’s intake since iodine is used to disinfect milking equipment
iron
most in body carried in proteins:
HEMOGLOBIN: o2 carrier protein of RBCs in bloodstream
MYOGLOBIN: o2 carrier protein of muscle cells
iron roles
carries oxygen and helps enzyme use o2
needed to make new cells, amino acids, hormones, neurotransmitters
liver adds iron to new RBC’s from bone marrow; recycled after 3-4 month in liver/spleen
iron loss
can b lost in nail clippings, hair cutting, skin shedding
- significant if you lose from bleeding; GI bleeds
iron gain
only 10-15% from diet actually absorbed but amount can increase/decrease if:
body supply diminished and needs it, or body supply abundant
hard to readily get rid of iron
Free iron is…
a powerful oxidant, can damage cells
iron deficiency
absorption not compensating for loss or low dietary intake, in stages
stage 1: decreased iron stores
stage 2: depleted iron stores
stage 3: iron deficient and anemic
iron deficiency anemia
more severe; depleted iron stores and low blood Hb
microcytic anemia
cells are smaller
hyperchromic
lighter red than normal
pica
craving non-foods; assoc w iron deficiency - you eat clay, soil, air freshener; shits bad for u and will inhibit iron absorption
risk factors of iron deficiency
being women (tend to eat less food and lose iron bc you bleed - menstruating or preg
being an infant that isn’t breastfed anymore, young child, adolescent
most common nutrient deficiency
iron toxicity
hard to excrete once absorbed
- iron overload defended against controlling iron absorption
- genetic component: white ppl tend to continue to absorb iron even in excess
CV
infection: bacteria thrive on iron-rich blood
vit c helps iron absorption
iron sources
preg women need supplement
iron forms: heme-bound (animal flesh) or nonheme (plants)
read meat, fish, poultry, shellfish, eggs - MEAT
legumes, green leafy veggies, dried fruit
iron absorption
MFP factor: meat, fish poultry
Zinc
occurs in very small quantity in body
zinc roles
everything
works w proteins in every body organ
helps over 300 enzymes
taste perception, wound healing, sperm production
zinc deficiencies
often misdiagnosed
mild: impaired immunity, abnormal taste, abnormal vision in dark
severe: affects growth, infections will worsen w malnutrition, wounds heal poorly, alters digestive sys
zinc risk groups
preg, poor, young, old, vegetarians
zinc toxicity
@ risk in supplements
can block copper absorption/lower body’s copper content
can reduce HDL blood concentrations
zinc sources
meat, fish, poultry, milk and milk products
plants not absorbed well; but some legumes and whole grains
selenium roles
antioxidant
selenium deficiencies
prostate cancer
heart disease/keshan disease
selenium toxicity
w long term supplementation (nausea, ab pain, hair loss, nerve abnormalities)
selenium sources
normal diet of unprocessed foods; widely distributed
- meats, shellfish, veggies in selenium rich soil
fluoride
not essential to life per say
fluoride roles
important for teeth - fluorapatite is resistant to decay
fluoride sources
fluoridated drinking water
fluoride deficiency
dental decay where fluoride is mising
fluoride toxicity
Fluorosis: Discolouration, pitting of tooth enamel during tooth development
Irreversible once developed
chromium roles
Blood glucose regulation with insulin; regulate release glucose energy
chromium deficiency
Impaired Insulin Action*; results in diabetes-like condition - fixed with supplements
Supplements however CANNOT cure actual diabetes
chromium sources
Widely distributed in food supply; unrefined foods, whole grains
Meat, whole grains, vegetable oil
copper roles
Forming hemoglobin and collagen
Can handle oxygen - enzymes depend on it, metabolism
Also handles iron
Superoxide dismutase: Unfucks free radical damage, is copper-dependent
copper deficiency
Excess zinc can interfere with copper absorption - deficiency
Menkes disease: Absorbed but not released into circulation
Disturbed growth and metabolism
Impaired immunity, arterial blood flow in adults
rare in severely malnourished infants
copper toxicity
Unlikely from foods; possible from supplementation
Wilson’s Disease: Copper accumulates in liver/brain; treated with Zinc supplements
Copper ring around the eye, pretty cool
copper sources
unimportant
osteomalacia
Vitamin D deficiency disease characterized by overabundance of unmineralized bone protein - Symptoms include bending of spine, bowed legs
osteoporosis
A reduction in bone mass in older people; the bone becomes porous and fragile
1/3 women and 1/5 men suffer from osteoporotic fractures; people w/ fractures may need LTC
Get a diet rich in calcium early on in life to prevent osteoporosis later in life
bone breaks and use of tobacco + alc
Smokers have less dense bones and alcoholism = undernutrition, fall risk
DASH Diet
Dietary Approaches to Stop Hypertension - Can help both salt-sensitive and non-sensitive
Achieves a lower blood pressure than restriction of sodium alone
Involves greatly increased intake of vegetables and fruits
Adequate amounts of nuts, fish, whole grains, low-fat dairy
Occasional small portions of red meat, butter, high-fat foods/sweets
Greatly reduces salt/sodium
Results in progressively lower sodium and lower blood pressure as well
Adding Mg, K, Ca, Protein, Fibre makes this drop even larger
Ex., whole grains, fruits, veggies, seeds, nuts, legumes
Low K intake raises blood pressure
High K intake prevents and corrects HTN
Physical activity also lowers BP
