nutr exam 3- trace minerals

where are trace minerals absorbed, what source is best absorbed

absorbed in small intestine, animal sources are generally better absorbed

what are the trace minerals

iron, iodine, zinc, copper, fluoride, selenium

what is trace mineral bioavailability influenced by

genetics, nutritional status, nutrient interactions, aging

true or false: trace mineral deficiences and toxicities are rare

true

what is the typical result of trace mineral deficiences

the failure to thrive and grow

where are trace mineral toxic levels usually at

not far above the estimated requirements

daily trace mineral intake

daily dietary needs are less than 100 mges

chromium and iodine essential function

help certain hormones

iron essential function

helps to maintain healthy red blood cells

fluoride essential function

protects teeth

iron, zinc, copper, manganese, and molybdenum essential functions

cofactors that work with enzymes in critical chemical reactions

iron

most abundant trace mineral in the body
absorption increased by vit C intake, decreased by tannic acid (tea, coffee) and calcium in milk
need more when pregnant or in childhood
absorption is influenced by iron stores- it increases if body stores are low
body only absorbs 10-15% of iron consumed

two forms of iron in food

heme iron and nonheme iron

heme iron

more easily absorbed, found in animals

nonheme iron

found in plants and animal foods, poorly absorbed

iron function

hemoglobin in red blood cells transports oxygen from lungs to tissues and picks up carbon dioxide wast from cells
myoglobin transports and stores oxygen in muscle cells
aids in brain function by helping enzymes that make neurotransmitters

daily iron intake

females 19-50: 18mg/day
females after menopause: 8mg/day
males: 8mg.day

iron UL

45 mg/day

iron sources

meat, fish, enriched grains and cereals, green leafy veggies

iron deficiency

anemia, women and vegans at higher risk, often due to blood loss

iron toxicity

hemochromatosis- most common genetic disorder in the US, causes the body to absorb too much iron and leads to lvier damage and infections

iodine function

needed by thryroid to make essential hormones, about 60% of thyroid hormones are iodide
synthesis of T4--> development of CNS

iodine intake

150 ug/day

sources of iodine

iodized salt, salt water fish
amount in foods is low

iodine deficiency

goiter- englarged thyroid gland
in fetal development- can cause cretinism (congenital hypothyroidism)

iodide

the ionic form of iodine
an essential mineral

zinc function

an essential trace mineral involved in gene expression, immune function, and cell growth
cofactor for many enzymes- in RNA synthesis, alcohol metabolism
wound healing, antioxidant, taste acuity, sexual development

zinc sources

chocolate, shellfish, meats, poultry, liver, whole grains

zinc absorption

reduced by nonheme iron in intestinal tract, high-fiber diet, phytates
enhanced by animal protein consumption

zinc intake

females: 8mg/day
males: 11mg/day

zinc UL

40mg/day

zinc deficiency

hair loss, delayed growth in children, loss of appetite, impaired sense of taste, diarrhea, delayed sexual maturation, impotence, skin rash
seen especially in pregnant women, children, elderly, and poor

copper function

cofactor for nine enzymes involved in redox reactions
- ATP production, iron metabolism, neural function, antioxidant function, connective tissue synthesis

two forms of copper

cupric (Cu2+): oxidized
cuprous (Cu+): reduced

copper sources

organ meats, shellfish, whole-grains, mushrooms, nuts, legumes

what causes copper bioavailability to decrease

antacids, iron

copper intake

900ug/day

copper UL

10,000ug/day

copper deficiency

usually consequence of high zinc suppliements
normocytic, hypochromic anemia
rare genetic disroder affects Cu status- Menkes disease

copper toxicity

wilsons disease- accumulates copper in the liver, brain, kidneys, and cornea leading to premature death if left undetected
excess copper can cause stomach cramps, nausea, diarrhea, vomiting, liver damage

fluoride function

not classified as essential bc the body does not require it for normal growth and development
maintains healthy teeth and strong bones- increases bone mineral density, reduced incidence of osteopororsis

fluorise absorption

in small intestine

fluoride sources

found naturally in plants and animals, often added to water supply
foods are not the best source- better to get from fluoridated drinking water and other beverages with it

fluoride deficiency

increased risk of dental cariesfl

fluoride toxicity

flurosis in teeth and bones
prevalent
GI upset, excessive production of saliva, watery eyes, heart probs, coma

selenium function

antioxidant, makes thyroid hormone active

selenium deficiency

may increase risk for heart disease

selenium sources

meats and other animal products, whole grains