Trace Minerals I Flashcards
Essential inorganic elements that are required in maintaining the normal functions in our body
Minerals
Important in bone health, growth and development, blood formation, and clotting and nerve impulses
Minerals
The essential minerals can be further divided into which 2 categories?
Major and trace minerals
Major minerals are required in amounts of more than
100 mg per day
Required in amounts of less than 100 mg per day
Trace minerals
Are typically the richest source of minerals and have the best bioavailability
Seafood
Nutritional status and the amount of mineral stored in the body will influence how much is
Absorbed
Often times compete with eachother for absorption in the GI tract
Minerals
Compete for the same protein carriers during absorption
Ca2+, Mg2+, Fe2+, Cu2+, and Zn2+
The bioavailability of minerals can also be reduced if the minerals are attached to binders such as
Oxalates or Phyates
An example of this is the oxylate that binds calcium in
Spinach
Is technically high in calcium but is a poor calcium source because of its high oxylate content
Spinach
Also bind and inhibit the bodies absorption of minerals
Phyates in plants and polyphenols in tea and coffee
Enhances the absoprtion of iron from plant foods
Vitamin C
Animal protein from meat, fish, and poultry enhances
Zn absorption
What are the 6 major trace elements we need to know?
Iron, zinc, copper, selenium, fluoride, iodine
Found in the highest amount in meat, fish, poultry, eggs dried peas, and beans
Iron
Whe menses and monthly blood loss have ceased, the RDA of iron for men and women is
Identical
The oxidized form of iron is
Ferric Iron (Fe3+)
The average adult body contains about
3-4g of iron
Free iron is very
Toxic
Iron is transported in circulation bound to
Transferrin
Approximately 70% of iron is in red blood cells as part of the
Heme in hemoglobin
What percentage of iron is bound to myoglobin in the heart and skeletal muscle?
5%
The rest of the iron is stored in the liver, spleen, and bone marrow as
Ferritin
When iron concentrations become abnormally high, liver converts ferritin into another storage protein called
-protects body from damage due to excess iron
Hemosiderin
Most commonly found in macrophages and is especially abundant in situations following hemorrhage, suggesting that it is related to phagocytosis of red blood cells and hemoglobin
Hemosiderin
What are the two forms of dietary iron found in food?
Heme and non-heme iron
Absorbed slowly and not affected by dietary consumption
Heme iron
The larger portion of iron consumption is from
Non-heme iron
Sources of non-heme iron include both
PLant and animal sources
Absorbed at a much slower rate
Non-heme iron
Only foods derived from animal flesh provide
-better absorbed
Heme iron
What are the two general types of factors affecting iron absorption?
Enhancing and inhibiting factors
Increased demands in periods of growth such as pregnancy and weight training results in
Increased iron absorption
Non-heme iron absorption is accelerated with the presence of animal proteins. Specifically by a protein called
Meat protein factor
Although there is no iron absorption in the stomach, increasing the acidity converts iron from
Fe3+ to Fe2+
Fe2+ is the form of iron that is
Absorbed by duodenum
The body suppresses the supply of iron during
Infection
The presence of antacids and PPis has what effect on iron absorption?
Inhibitory
Very little ferritin is made, which allows larger amounts of iron bound to transferrin to get into circulation when
Iron levels are low
If intestinal cells are sloughed off before iron is absorbed, then the iron is
Excreted in feces
Iron is absorbed in the
Duodenum
Heme iron is transported across the brush border and enters the same pool as
Non-heme iron
For transport across the brush border, iron must be in the
Fe2+ form
Helps to transport iron out of enterocytes
Ferroportin
A ferroxidase bound on the basolateral side of enterocytes
Hephaestin
Oxidises Fe2+ to Fe3+ so that iron can be incorporated into transferrin
Ferroxidase
Another protein with ferroxidase activity is
-mainly found as a soluble protein originating from the liver
Ceruloplasmin
Carrie smore than 95% of the total copper in healthy human plasma
Ceruloplasm
The most common nutrient deficiency world wide
Iron deficiency
People with celiac disease are at risk for
Iron deficiency
Has symptoms of fatigue, faintness, cold or abnormal sensations in extremities, SOB, immunosuppression, and low IQ
Iron deficiency
Heme iron has a role as a prosthetic group in several enzymes needed to destroy microorganisms. Thus iron deficiency results in
Immunosuppression
The craving and consumption of unusual nonfood substances such as dirt, clay, or ice seen with iron deficiency
Pica
Iron deficiency develops in stages. First iron stores diminish, then transport iron decreases, and finally
Hemoglobin production fails
The most commonly used tests to check for iron deficiency
Hemoglobin and hematocrit
Excess blood transferrin would indicate
Low iron levels
Low serum iron and ferritin levels with an elevated TIBC are diagnostic of
Iron deficiency
A measure of total amount of iron that transferrin can carry
Total Iron-binding capacity (TIBC)
In iron deficiecy anemia, hemoglobin synthesis decreases, resulting in red blood cells that are
Pale (hyochromic) and small (microcytic)
We can remember the association of iron deficiency anemia as a
Hypochromic, microcytic anemia
Angular somatitis and glossitis with painful swelling of the tongue is a presentation of
Iron deficiency
Long-standing, severe iron deficiency affects the cells that generate the finger nails, producing
Koilonychia (spoon shaped nails)
A genetic disease in which iron is absorbed at a high rate despite elevated liver stores
Hemochromatosis
May cause bronzed pigmentation to the skin and damaged liver and pancreatic tissue, possibly causing DM
Prolonged hemochromatosis
Diabetes mellitus caused by hemochromatosis is referred to as
Bronze diabetes
Excess iron in the eldery poses a risk for
Heart disease and Cancer
Seafood, especially oysters, steak, crab, and milk are good dietary sources of
Zinc
When zinc enters the mucosal cells, it binds the protein
Metallothionein
Large doses of zinc can override a
Mucosal block
Both dietary zince and zinc-rich pancreatic secretions via enteropancreatic circulation are available for
Absorption
Numerous proteins participate in zinc transport. But the major protein is
Albumin
Some Zn also binds
Transferrin
Essential for heme, DNA and RNA synthesis, reproduction, growth and development, and senses of taste and smell
Zinc
Stabilizes cell membrane proteins and receptor proteins for vitamin A, D, and thyroid hormone
Zinc
Zinc is essential for gene transcription as part of
Zinc Finger proteins
Vegetarians, alcoholics, lactating women, and heavy smokers are all at risk for
Zinc deficiency
Those with malabsorption and chronic diarrhea may benefit from
Zinc supplementation
Inhibits zinc absorption and promotes excretion
Alcohol
Severe zinc deficiency may also result from a rare genetic condition called
Acrodermatitis enteropathica
Acrodermatitis enteropathica develops after weaning and results in impaired
Intestinal zinc absorption
Can be manifested as symptoms of poor appetite, changes in smell and taste, and poor wound healing
Zinc deficiency
Males with growth retardation, hypogonadism, delayed onset of puberty, and failure of secondary sex characteristics to develop may have
Zinc deficiency
Yeast fermentation in the preparation of breads reduces the effect of
Phyates
An autosomal recessive metabolic disorder characterized by periorificial and acral dermatitis and alopecia
Acrodermatitis enteropathica
Zinc toxicity is rare. But the symptoms include
Diarrhea, nausea, and vomitting
Zinc toxicity can impair immune function and reduce
Copper absorption
Genetic syndrome that results in increased copper storage
-patients benefit from zinc supplementation
Wilson Disease
Liver, shellfish, nuts, seeds, lentils, soy products, and DARK CHOCOLATE are good sources of
Copper
A poor source of copper, but may promote copper absorption as we have seen with non-heme iron absorption
Meat
Copper absorption occurs in the small intestine and is increased in an
Acidic environment
Phyates, calcium, fiber, and zinc decrease
Copper absorption
Part of lysly oxidase and is therefore important for the production of skin, hair, and CT
Copper
Copper is a cofactor for superoxide dismutse, which is essential for the protection of cells from
Reactive oxygen species
Copper also participates in the maintenance of the myelin sheath and the
Nervous system
Cofactor for monoamine oxidase system involved in the synthesis of neurotransmitters
Copper
As part of ceruloplasm, it promotes iron transportation
Copper
The major copper containing protein in the plasma
Ceruloplasmin
Ceruloplasm is important for recycling
Iron in macrophages
