Trace Minerals Flashcards
what are trace minerals
Essential mineral nutrients the human body requires in relatively small amounts (< 100 mg daily)
what are some trace minerals
Iron, Zinc, Iodine, Selenium, Copper, Manganese, Fluoride, Chromium and Molybdenum
Trace mineral content dependent upon
processing, and soil and water composition
__ and __ impacts bioavailability
Dietary factors, human body
are trace mineral deficiencies local
no, Wide reaching impacts due to activity in many body systems
Generally: failure to grow in children
what are the two iconic states of iron
Ferrous iron (reduced) Fe++ Ferric iron (oxidized) Fe+++
Most of body iron located in
Hemoglobin (RBCs)
80% of body’s iron is
Myoglobin (muscle cells)
__ holding protein of the muscle cells
O2
Fe balance maintained thru
absorption
what is ferritin
Iron storage protein
ferritin receives Iron from __ & stores in
GI tract, mucosal cells of SI
what is transferrin
Iron transport protein
what does transferrin do
Takes Iron from ferritin & transports iron to rest of body
what happens to iron from food after it is ingested
mucosal cells in the intestine store excess iron in mucosal ferritin
what happens to the iron stored in the SI if the body does not need it
iron is not absorbed and is excreted in shed intestinal cells instead. thus, iron absorption is reduced when the body does not need iron.
what happens to the iron stored in the SI if the body needs it
mucosal ferritin releases iron to mucosal transferrin, which hands off iron to another transferring that travels through the blood to the rest of the body
the absorption heme and nonheme iron partly depends on
the source
where is heme iron found
only in foods from animal flesh such as meats poultry and fish
which iron is absorbed better
heme (25%)
what are the sources of nonheme iron
plant and animal-derived foods
which iron is less well absorbed
nonheme (17%)
what factors enhance absorption of iron
MFP factor and vitamin C
what is MFP factor
Peptide factor released during the digestion of meat, fish and poultry that enhances non-heme iron absorption
how does vitamin C do to iron absorption
Improves non-heme Fe absorption
Iron from supplements is not influenced by Vitamin C
what is recommended for iron absorption
take supplemental iron between meals
what are some iron inhibiting factors
- *Phytates (in legumes, whole grains and rice)
- Vegetable proteins (soybeans, legumes and nuts)
- Fibers
- Oxalates
spinach - Ca (milk)
- EDTA (food additive)
- Tannins
- coffee, tea, grains, oregano, red wine &; some F
absorption of Fe depends on __ aka__
lifestage and growth; More mucosal ferritin & blood transferrin made when needs are greater
__ delivers iron to bone marrow & other tissues
Blood transferrin
Bone marrow uses iron to make new
RBCs
where is ferritin stored
the liver and also in bone marrow and the spleen
what is Hemosiderin
Iron-storage protein made in times of iron overload
where is Fe lost
in blood, GI tract feces, and minute amounts in urine, sweat & shed skin
what is hepcidin
hormone produced by the liver that regulates iron balance by limiting absorption from the SI and controlling release from the liver, spleen and bone marrow
when is production of hepcidin increased
in iron overload and decreases in iron deficiency
what is the most common nutrient deficiency worldwide
Fe
how many people have iron deficiency anemia
1.6 billion
__ leads to Fe deficiency
blood loss
Fe varies by __
life stage
Severe depletion of Fe stores that results in
low Hgb & small, pale RBCs
what is hypochromic anemia
blood cells are paler than normal
what is microcytic anemia
blood cells are smaller than normal
what are symptoms of hypo chromic an microcytic anemia
- Fatigue & weakness
- Apathy
- Poor resistance to cold
- Pallor
- Pale skin
what happens when iron is low
hemoglobin synthesis is impaired
what happens during stage 1 of iron deficiency
- Fe stores diminish
- Measure of serum ferritin reflect stores (decreases); most valuable at early stage assessment
- Serum ferritin increases with infection, may lead to inaccurate dx.
what happens during stage 2 of iron deficiency
- Decrease in transport iron
- Serum iron falls
- Transferrin increases to adapt
- Transferrin saturation decreases as iron stores decline
what happens during stage 3 of iron deficiency
- Limits Hgb production
- Erythrocyte protoporphyrin accumulates (precursor to Hgb)
- Hematocrit drops
what happens to behavior during iron deficiency
- Impairs energy metabolism and neurotransmitter synthesis
- Complete oxidation of pyruvate is impaired
- lazy/apathetic
what is pica
- Symptom of Fe deficiency
- Craving and consumption of nonfood substances
- Worsens anemia
what is pagophagia
craving for ice
what is geophagia
craving for ceramic/chalky things
what is amylophagia
uncooked starch
what is hemochromatosis
Hereditary defect in Fe metabolism characterized by deposits of Fe-containing pigment in many tissues, with tissue damage
Hereditary Hemochromatosis is the most common genetic d/o in US
what is the most common genetic disorder
hemochromatosis
what are signs and symptoms of hemochromatosis
apathy, lethargy, fatigue, and liver damage
what are some treatments for Fe toxicity
chelating agents; low iron intake; avoid high dose vitamin C
what is the UL poisoning
45mg/day for adults
who is at greatest risk for Fe poisoning
young children
what are some symptoms for Fe poisoning
Nausea/Vomiting, diarrhea, rapid heartbeat, weak pulse, dizziness, shock, confusion–> death probably due to heart failure, respiratory distress and internal bleeding
Fe oxidizes
LDL
what are the main sources of Fe
- MFP-meats, fish, poultry
- legumes
- eggs
- dark, green vegetables
- fruit
- Fe enriched foods bread/cereal but not absorbed as well as naturally occurring Fe, eat with Vitamin C or MFP
what is a poor source of Fe
milk groups
Vegetarians need __ times as much iron to make up for low bioavailability of iron in diet.
1.8
who does not usually meet iron needs
women, because of higher requirements and decreased kcal needs
Iron content in eggs can triple when
cooked in an iron skillet
which is absorbed better: supplemental or from foods
from foods
an empty or full stomach is better for Fe absorption
empty
supplemental iron may cause
constipation
should you take vitamin c with SUPPLEMENTAL iron
no need
what does vitamin C do to iron
converts ferric iron to ferrous iron
what are the RDAs for Fe
men: 8 mg/day
women: 18 mg/day (19-50yr), 8mg/day (51yr+)
what is the upper level of iron
45 mg/day
what are some significant sources of iron
red meats, fish, poultry, shellfish, eggs, legumes, dried fruits
what are iron toxicity symptoms
GI distress
__ is a cofactor required by >100 enzymes
zinc
what are some functions of zinc
- Cofactor required by >100 enzymes
- Supports work of proteins
- Helps protect from free radicals
- Growth & development (big time)
- Immune fx
- Synthesis, storage & release of insulin
- Interacts with platelets in blood clotting
- Affects thyroid hormone fx
- Influences behavior and learning performance
- Aids in producing retinal in visual pigments and RBP
- plays role in taste perception
- plays role in wound healing
- plays role in sperm production
- plays role in fetal development
zinc absorption ranges from
15-40%
As zinc intake increases, absorption
decreases & vice-versa
what is the primary transport of zinc
albumin
in addition to albumin, zinc also binds to
transferrin
where is zinc lost
in feces, urine, shed skin, hair, sweat, menstrual fluids, semen
Zinc deficiency is uncommon in developed countries, but accounts for 1 in 20 childhood deaths in
Africa, Asia and Latin America
what are some results of zinc deficiency
- Severe growth retardation
- Hypogonadism
- Hinders digestion & absorption–>diarrhea worsening nutrient status & overall nutritional status
- Impaired immune system–> infections
- Chronic deficiency: damaged CNS, brain & poor motor development & cognitive performance
- Disturbed thyroid fx & metabolic rate
- Slows wound healing
what other vitamin mimics zinc deficiency
A, zinc deficiency impairs vitamin A metabolism
what are symptoms of Zn toxicity
Vomiting, diarrhea, headaches, exhaustion @ 50 mg
what is the UL for zinc
40mg
in what foods is Zn found
- Protein rich foods
- Shellfish (Oysters)
- Meats
- Poultry
- Liver
- Legumes & whole grains
what are the RDAs for Zn
men: 11mg/day
women: 8mg/day
