Flashcards in Exam #1: Minerals II Deck (71):
Where is the majority of the body's iron found?
What is the point of regulation for iron?
What are the two types of iron? Where do the different types of iron come from?
Heme= animals ONLY
Nonheme= BOTH plant and animal sources
Which form of iron is more readily absorbed?
What can increase the absorption of non-heme iron?
- Acids e.g. Vitamin C
What are the major functions of iron?
1) Center of heme/ O2 transport
2) Enzyme component
What is the relationship between Vitamin C & Iron?
Vitamin C enhances absorption of non-heme iron
What is the relationship between Copper & Iron?
Copper - ceruloplasmin- mobilizes iron from stores in the liver
*****Note that without copper/ ceruloplasmin, iron essentially gets "stuck" in the liver and can cause liver damage
What is the relationship between Zinc & Iron?
- Iron decreases the absorption of zinc
****Note that zinc competes for the same portion of the absorptive pathway as iron; thus, high zinc will decrease iron (especially non-heme) absorption
What is the relationship between Vitamin A & Iron?
Vitamin A deficiency reduces the distribution of iron to tissue
What is the relationship between Lead & Iron?
Lead inhibits the enzyme necessary for heme synthesis AND the enzyme necessary for iron incorporation into heme
What are the four groups that are most susceptible to iron deficiency in the US?
1) Infants and young children
3) Premenopausal women
4) Pregnant women
What are the symptoms of iron deficiency?
- Angular stomatosis
What are the lab findings commonly seen in iron deficiency?
- Decreased Hb
- Microcytic anemia
- Decreased serum iron
- Increase TIBC
- Decreased serum ferritin
****Note that iron deficiency can occur without anemia
What are the symptoms of iron toxicity?
- Tissue damage (liver & brain)
What is the most typical acute cause of iron toxicity?
****Think gummie vitamins
What are the chronic causes of iron toxicity
- Hemolytic anemia
- Idiopathic hereditary hemochromatosis
- Iron-loading anemias i.e. thalassemia & sideroblastic anemia
What is the treatment for iron toxicity?
Phlebotomy & chelation
*****Chelation= drug that binds iron so that it can be more readily excreted, best for chronic toxicity
What are the major functions of zinc?
- Enzyme cofactor
- Functions in tissue/ cell growth & replication, skin integrity, bone formation, and wound healing
- Carbohydrate metabolism (incorporation into insulin)
What are the major nutrients, macorminerals, and microminerals essential to wound healing?
- Vitamin C
What is the relationship between zinc & Vitamin A?
Zinc deficiency is associated with decreased mobilization of retinol (Vitamin A) from liver
*****Zinc is necessary for hepatic synthesis of retinol binding protein
What is the relationship between zinc & copper?
Excessive zinc intake decreases copper absorption
What is the relationship between zinc & Ca++?
Zinc supplements decrease Ca++ absorption
What is the relationship between zinc & folate?
- Folate digestion requires zinc
- Deficiency in zinc could lead to folate deficiency
What is the relationship between zinc & cadmium?
Cadmium is a competitive zinc antagonist
What is the relationship between zinc & lead?
- Lead may replace zinc in enzyme for heme synthesis
- Toxic levels of lead thus inhibit heme synthesis
What are the symptoms of zinc deficiency?
1) Delayed wound healing
6) Nonspecific peri-oral rash
What are the symptoms of zinc toxicity?
- Metallic taste
- Copper deficiency leading to iron deficiency
*****Remember, HIGH zinc= LOW Copper-->LOW Iron
What are the functions of copper?
The major functions of copper include:
- Enzyme cofactor
- Electron donor/ acceptor
- Gene expression by binding to transcription factors
What are the enzymes that utilize copper as a cofactor?
2) Cytochrome C
3) Superoxide dismutase
What is the relationship between copper and zinc?
- Toxic levels of zinc inhibits copper absorption
- Copper is an essential component of the enzyme ceruoplasmin
- Ceruloplasmin mobilizes iron from stores in the liver
****Thus, HIGH ZINC = LOW COPPER and LOW IRON
What is the relationship between copper and molybdenum?
Molybdenum causes copper excretion
What is the relationship between copper and selenium?
Copper deficiency decreases selenium-dependent enzyme function
What are the symptoms of copper deficiency?
- Hypochromic anemia
- Imparied immune function
- Demineralization of bone
What is Wilson's Disease?
- Disease characterized by defect in transporter required for biliary excretion of copper
- Leads to accumulation of copper in liver, brain, & kidneys
- Causes mental retardation & liver damage
What is Menke's Syndrome?
- Disease characterized by defect in transported required for copper into fetus
- Causes slow growth, mental degradation, and kinky white hair
What are the symptoms of copper toxicity?
****Note that this is v. rare and occurs via water contamination or accidental ingestion
What are the functions of Selenium?
- Maintenance and induction of cytochrome p450*
- Cofactor for glutathione peroxidase
- Iodine metabolism; no selenium can lead to iodine deficiency
What is the relationship between selenium and lead?
Lead cause a decrease in tissue concentrations of selenium
What is the relationship between selenium and iron?
Iron deficiency decreases synthesis of glutathione peroxidase & selenium concentrations
What is the relationship between selenium and copper?
Copper deficiency decreases activity of selenium-dependent enzymes
What is the relationship between selenium and methionine?
Methionine deficiency causes decreased selenium potency
What is Keshan Disease?
Regional selenium deficiency seen in China that is characterized by:
- Cardiomyopathy w/ cardiogenic shock
- Necrosis of the heart
*****Note that this disease also requires exposure to COXSACKIE virus
What is Kashin-Beck's Disease?
Regional selenium deficiency seen in China that is characterized by:
- Degeneration & necrosis of joints
What are the symptoms of Selenosis?
- Hair & nail loss
- Inhibition of protein synthesis
*****Note that this can be seen in miners, and those with an excessive intake
What are the functions of iodine?
1) Iodine is required for the synthesis of thyroid hormones
2) Controls basal metabolic rate, growth, development, protein synthesis, and energy metabolism
What are the symptoms of iodine deficiency?
- Decreased cold tolerance
- Coarse hair
What are the symptoms of iodine toxicity?
- Weight loss
- Heat intolerance
What is the major function of fluoride?
Mineralization of teeth and bones
What nutrients reduce uptake of flouride?
What nutrients increase flouride uptake?
What are the symptoms of flouride deficiency?
- Dental carries
- Decreased integrity of skeletal tissue
What are the symptoms of fluorosis?
- Mottling of teeth
- Changes in bone, kidney, & nerve/muscle function
What are the functions of chromium?
- Binds nicotinic acid & amino acids to form glucose intolerance factor
- Glucose intolerance factor initiates disulfide bridging between insulin and the insulin receptor; thus, the effectiveness of insulin is INCREASED with chromium
- Glucose & lipid metabolism
What are the symptoms of chromium deficiency?
- Glucose intolerance
- Insulin resistance
What are the symptoms of chromium toxicity?
- Respiratory distress
*****Note that this comes from inhalation or direct skin contact
What are the functions of manganese?
- Enzyme activator & constituent of metalloenzymes
- Modulator of second messenger pathways
What are the symptoms of manganese deficiency?
Decreased growth of hair & nails
Low blood cholesterol
*****This is very rare and typically only seen if intentionally eliminated from the diet
What are the symptoms of manganese toxicity?
- Liver failure
- Parkinson-like sx
hare the functions of molybdenum?
Component of enzymes involved in redox reactions
What are the symptoms of molybdenum deficiency?
- High blood methionine
- Low blood xanthine
- Low blood uric acid
*****Associated with esophageal cancer & long-term TPN admin.
What are the symptoms of molybdenum toxicity?`
Gout due to high uric acid concentrations
List the ultra-trace elements.
What is the most likely source of aluminum toxicity?
Food additives and antacids
What are the symptoms of aluminum toxicity?
- Renal encephalopathy
What is the source of cadmium toxicity?
What are the symptoms of cadmium toxicity?
- Osteomalacia by antagonizing Ca++ metabolism
- Anemia by antagonizing zinc & iron
What is the source of mercury toxicity?
Pollution (run off that accumulates in fish)
What are the symptoms of mercury toxicity?
- Visual problems
- Mental retardation
- Neuromuscular problems in infants
What is the source of lead toxicity?
Lead paint in older buildings & pottery