Minerals - RM Flashcards
What is B9? Is it hematopoietic or energy releasing?
folate, hematopoietic
What is folate the precursor of? What reactions is it needed for?
THF (tetrahydrofolate), needed to create precursors for DNA and protein synthesis
What does folate deficiency cause?
Neural tube defects, macrocytic anemia, hyperhomocysteinuria
What is folate metabolism interdependent on?
cobalamin metabolism
Why does folate deficiency cause anemia and present in pregnancy?
affects DNA synthesis and RBCs have rapid turnover, and fetus developing needs great amount of DNA synthesis
What is B12?
cobalamin
What is B12 a coenzyme in? What conversion does it catalyze?
coenzyme in methionine synthesis (from homocysteine), conversion of methylmalonylcoA to succinylcoA
Why is cobalamin needed in folate metabolism?
uses N5 methyl THF in homocysteine to methionine conversion and regenerates THF
What does cobalamin deficiency cause?
pernicious anemia (macrocytic), demyelination
What symptoms distinguish cobalamin deficiency from folate deficiency?
neurological symptoms
Why do elderly have cobalamin deficiency?
decreased intrinsic factor secretion
What is different about vit B12 than other water soluble vitamins?
it gets stored effectively in the liver
What is megaloblastic anemia?
larger RBCs due to deficiency in nucleotides from decreased DNA synthesis (cell size increases without dividing)
How are minerals classified as macrominerals vs. microminerals?
macrominerals >100-200 mg/day needed
microminerals <100 mg/day needed
What are the functions of calcium?
component of bone, signaling, localization of clot in coagulation, muscle contraction
What vitamin is calcium coregulated with? How?
vitamin D, needed for calcium absorption
What is the major reservoir of calcium in the body? How does it respond when there is low Ca?
bone, with low Ca, bone will mobilize Ca (resorption)
What is osteoporosis?
porous bone caused by bone resorption due to calcium deficiency
What is magnesium essential for?
enzymes using MgATP as substrate (ATP synthase, Na/K ATPase, SERCA pump)
Where does Mg deficiency cause?
weakness, tremors, cardiac arrhythmia
What is the function of phosphorus?
major component of bone, constituent of nucleic acids and phospholipids, needed in all energy producing reactions
What does phosphorus deficiency cause? Is it common or rare?
very rare- rickets, muscle weakness/breakdown, seizures
What is the function of iron?
oxygen and carbon dioxide transport in Hb, oxidative phosphorylation (FeS center), cofactor in nonheme iron proteins and cytochromes
What does iron deficiency cause?
microcytic anemia
decreased immunity
What causes decreased immunity in iron deficiency?
lack of myeloperoxidase in macrophages
Who is susceptible for iron deficiency?
pregnant women, menstruating women (ongoing blood loss)
What are the two barriers to iron absorption?
- release of Fe3+ from food–needs to be released by low pH in stomach
- Fe3+ needs to be reduced to Fe2+–vitamin C or other reducing agents must be available
What is hepcidin?
signals iron sufficiency and prevents export of Fe2+ from mucosal cell by downregulating exporter
Why are cells smaller in iron deficient anemia?
RBCs undergo more cell divisions in bone marrow waiting for Hb synthesis to occur (that won’t because doesn’t have Fe center for heme)
Why is iron toxic?
- when improperly localized or bound, it can catalyze production of reactive oxygen species
- transition metals can repalce one another at enzymes active site
What is hemochromatosis?
iron overload leads to iron deposit in tissues, compromises liver, pancreatic, cardiac and mitochondrial function, leading to lactic acidosis
What is an acute cause of iron overdose?
consumption of adult iron supplements
How does copper assist in iron absorption?
through ceruloplasmin which oxidizes Fe2+ to Fe3+ to help it bind transferrin for distribution
What reactions is copper a cofactor for?
collagen synthesis, FA metabolism, elimination of reactive oxygen species
What does copper deficiency cause?
anemia-from link to Fe metabolism
hypercholesterolemia-from loss of Cu enzyme desaturase
fragility of large arteries, bone mineralization- from loss of lysyl oxidase
demyelination
What is Menke’s syndrome?
genetic disease, mutation in Cu transporter ATP7A, needed to take up Cu into golgi to supply Cu to enzymes
(if Cu missing, secretes apoenzymes instead of active ones)
What deficiency can excessive Zn consumption cause?
copper deficiency, due to metals competing for same transporter in initial uptake and substitution at active site
What is Wilson’s disease?
mutation in ATP7B resulting in Cu overload, if not sequestered properly, builds up in liver resulting in liver failure and cancer, as well as NS symptoms
What does zinc deficiency first present as?
scaly dermatitis
What is chromium a component of? What does it do?
chromodulin, facilitates insulin binding to receptors
What does chromium deficiency cause?
impaired glucose tolerance from reduced insulin effectiveness
What is the function of iodine?
incorporated into T3 and T4, regulates BMR
How are minerals classified as macrominerals vs. microminerals?
macrominerals >100-200 mg/day needed
microminerals <100 mg/day needed
What are the functions of calcium?
component of bone, signaling, localization of clot in coagulation, muscle contraction
What vitamin is calcium coregulated with? How?
vitamin D, needed for calcium absorption
What is the major reservoir of calcium in the body? How does it respond when there is low Ca?
bone, with low Ca, bone will mobilize Ca (resorption)
What is osteoporosis?
porous bone caused by bone resorption due to calcium deficiency
What is magnesium essential for?
enzymes using MgATP as substrate (ATP synthase, Na/K ATPase, SERCA pump)
Where does Mg deficiency cause?
weakness, tremors, cardiac arrhythmia
What is the function of phosphorus?
major component of bone, constituent of nucleic acids and phospholipids, needed in all energy producing reactions
What does phosphorus deficiency cause? Is it common or rare?
very rare- rickets, muscle weakness/breakdown, seizures
What is the function of iron?
oxygen and carbon dioxide transport in Hb, oxidative phosphorylation (FeS center), cofactor in nonheme iron proteins and cytochromes
What does iron deficiency cause?
microcytic anemia
decreased immunity
What causes decreased immunity in iron deficiency?
lack of myeloperoxidase in macrophages
Who is susceptible for iron deficiency?
pregnant women, menstruating women (ongoing blood loss)
What are the two barriers to iron absorption?
- release of Fe3+ from food–needs to be released by low pH in stomach
- Fe3+ needs to be reduced to Fe2+–vitamin C or other reducing agents must be available
What is hepcidin?
signals iron sufficiency and prevents export of Fe2+ from mucosal cell by downregulating exporter
Why are cells smaller in iron deficient anemia?
RBCs undergo more cell divisions in bone marrow waiting for Hb synthesis to occur (that won’t because doesn’t have Fe center for heme)
Why is iron toxic?
- when improperly localized or bound, it can catalyze production of reactive oxygen species
- transition metals can repalce one another at enzymes active site
What is hemochromatosis?
iron overload leads to iron deposit in tissues, compromises liver, pancreatic, cardiac and mitochondrial function, leading to lactic acidosis
What is an acute cause of iron overdose?
consumption of adult iron supplements
How does copper assist in iron absorption?
through ceruloplasmin which oxidizes Fe2+ to Fe3+ to help it bind transferrin for distribution
What reactions is copper a cofactor for?
collagen synthesis, FA metabolism, elimination of reactive oxygen species
What does copper deficiency cause?
anemia-from link to Fe metabolism
hypercholesterolemia-from loss of Cu enzyme desaturase
fragility of large arteries, bone mineralization- from loss of lysyl oxidase
demyelination
What is Menke’s syndrome?
genetic disease, mutation in Cu transporter ATP7A, needed to take up Cu into golgi to supply Cu to enzymes
(if Cu missing, secretes apoenzymes instead of active ones)
What deficiency can excessive Zn consumption cause?
copper deficiency, due to metals competing for same transporter in initial uptake and substitution at active site
What is Wilson’s disease?
mutation in ATP7B resulting in Cu overload, if not sequestered properly, builds up in liver resulting in liver failure and cancer, as well as NS symptoms
What does zinc deficiency first present as?
scaly dermatitis
What is chromium a component of? What does it do?
chromodulin, facilitates insulin binding to receptors
What does chromium deficiency cause?
impaired glucose tolerance from reduced insulin effectiveness
What is the function of iodine?
incorporated into T3 and T4
What does iodine deficiency cause?
goiter-enlarged thyroid gland due to increased TSH because of low TH (TSH stimulates thyroid growth)
What is selenium a component of?
antioxidant enzymes (glutathione peroxidase), deiodinase enzymes in T3 and T4 metabolism
What is Keshan disease a deficiency of? What does it cause?
selenium, cardiomyopathy and cretinism
What 3 enzymes involve manganese?
arginase, pyruvate carboxylase, superoxide dismutase
What enzyme involves molybdenum?
xanthine oxidase
What is fluoride important for?
incorporated into bone and teeth, strengthens them
What is boron involved in?
bone formation
What are the common deficiencies in children?
Fe, Ca
What are the common deficiencies in teens?
Ca, Mg, possibly vit A, C, B6
What are common deficiencies in women?
Ca, Fe, Mg, vit B6, folate
What are common deficiencies in elderly?
Vit B6, B12, vit D, Zn, chromium
What are common deficiencies in alcoholics?
many, especially folate, B6 and thiamine
