Exam 3 Flashcards
which other mineral does Mn compete with and why
Fe (next to each other on the periodic table)
-compete for binding sites
-their status is inversely related (high levels of one can mean low levels of the other)
why is Mn a trace element (plasma concentration)
1 part per billion (hard to analyze)
where is Mn mostly found in the body
Bone
what is the form of transport of Mn, how is it excreted
-1 to 5% absorption, infants 20%
-active transport with ZIP
-90% excreted with bile through feces
what 3 enzymes does Mn constitute
-arginase (formation of urea)
-pyruvate carboxylase (pyruvate to oxaloacetate)
-superoxide dismutase (by-product of O2 metabolism)
3 functions of Mn apart from being an enzyme constituent
- bone, cartilage and connective tissue formation
- brain and CNS functions
- glucose interactions (+ glucose = + Mn uptake in pancreas)
Mn in relation to chickens
Mn chelates with lysine and glutamic acid are used as fattening agent (doesn’t work for humans, just animals) b/c makes Mn more bioavailable and efficient at supporting growth
how is deficiency of Mn seen (one condition + additional symptoms)
-Perosis aka slipped tendon disease (1st noticed in baby chicken)
-head retraction
-lost sighting reflex
-osteoporosis
picture of bumps on skin
Mn deficiency; Milaria Crystallina
UL of Mn
9 mg
where has toxicity of Mn been found and why
-miners working in Chile because of the inhalation of Mn dust
-dry cell battery factories in India
-contaminated water wells
Mn toxicity symptoms (connect back to functions of Mn)
-hyperirritability
-violence
-hallucinations
-libido problems
-incoordination
-shared symptoms with Parkinson’s
what can cause Mn toxicity? what are the symptoms?*
-can’t happen from diet
-inhalation of Mn dust in welding/ mines, dry cell battery factories, contaminated water wells
-can cause: hallucinations, symptoms similar to those of Parkinson’s disease
list 3 enzymes that require Mn and their relevance*
-arginase: necessary for formation of urea
-pyruvate carboxylase: necessary for conversion of oxaloacetate -> pyruvate
-superoxide dismutase: catalyzes dismutation of superoxide radical (protects cell from ox stress)
DRI for Mn
2.3 mg men
1.8 mg women
UL: 9 mg
*Europe average requirement: 3 mg
best source of Mn
Pineapple
Clams, oysters, mussels (but warm water = growth of bacteria)
renal failure and Mn toxicity
NOT a symptom
main function of Cr, why is it important
TRIVALENT Cr for insulin, sugar and lipid metabolism
what happens to Cr with age
tissue levels decline
*only mineral where this happens
what enhances Cr absorption
-vitamin C
-aspirin
-picolinate (sold to treat Cr deficiency and weight loss)
inhibitors of Cr
-neutral/ alkaline environment (antacids), Cr requires an acidic environment to be absorbed
-oxalates
diff between hexavalent Cr and trivalent Cr in terms of health effects *
-hexavalent is toxic and a known carcinogen, associated with industrial contamination
-trivalent Cr is biologically active and needed for glucose metabolism
what are the deficiencies seen in Cr studies
-TPN
-Cr didn’t moderate glucose levels in healthy people
-no effect of Cr in total cholesterol or LDL, just slightly decreased HDL
what is perosis? and it’s second name? in what population is it seen? *
Perosis is also known as slipped tendon disease. It’s a Mn deficiency related to underdeveloped, short and thickened bones in chickens.
how does Cr affect glucose and cholesterol? *
Cr did not help improve glucose in a healthy population, and showed no change in total + LDL cholesterol but slightly decreased HDL
what were health effects seen in Hinkley, CA due to hexavalent chromium contamination? what happened and what was the significance? how was this publicized?*
As seen in the award winning movie Erin Brockovich, there was hexavalent chromium contamination in the water in this town and the people came to realize becuase of tumors and respiratory issues they experienced (prolonged exposure). there was a class action law suit (largest ever) which was settled in the end for 333 million.
difference between US and European positions on trivalent Cr essentiality? why?*
-US recognized it as essential because of role in insulin, sugar and metabolism
-Europe found insufficient evidence to support Cr supplementation can reverse deficiency
what role does Cr play in insulin, sugar and glucose metabolism?*
-biologically active form of Cr= glucose tolerance factor
-helps uptake glucose into cell via insulin signaling
-Transferrin-> brings Cr to the cell
-Cr binds to apochromodulin
-Chromodulin activates insulin and facilitates bringing glucose into the cell
example foods high in Cr
red wine*
broccoli, potatoes, grape juice, whole wheat bread
where in the body is fluoride found?
99% in bones and teeth
F, how much is absorbed by adults vs children
50% adults, 80% children
functions of F, is it essential?
-it is not needed for essential function
-promotes new bone formation (teeth)
-inhbits demineralization
relationship between cancer and fluoride toxicity
none
who should avoid living in areas with high fluoridated water?
pregnant women
why is fluoride not used to treat osteoporosis?*
causes bones to be too brittle -> breaking and difficulty turning them back to normal
how is water fluorinated in Atx? what amount is used? *
taken out of the water supply of the city, then added back with a concentration of 0.7ppm
why is it important to have topical fluoride applied by a dentist? *
bacteria that make up plaque in teeth produce acid, creating caries.
topical fluoride enters rods of tooth to remineralize and prevent plaque formation
what causes fluorosis? what amounts are linked to this disease? what are the two types and their symptoms? *
- dental fluorosis: discoloration of teeth caused by fluoride toxicity (ex: excess F in infancy + childhood) -> White lines, flecks and brown stains on teeth
- Skeletal fluorosis: more rare, when water levels are 8 ppm or higher. -> joint stiffness, brittle bones, muscle wasting….
main points of controversy regarding fluoridated water. what is the most recent concern, does it have validity? *
-most recent concern is that high F levels in water lead to children with lower IQ, it’s not valid though because this claim has not been tested in areas where there is actually excess F in water like Tyler, Tx. (only 1% of US has access to waters with levels so high)
-goal is to reduce tooth decay
-opponents say it will cause fluorosis or even cancer (no link though)
why should children only use a small amount of toothpaste?
to prevent dental fluorosis
Fluoride DRI and UL
4 mg/d, UL= 10mg
main source of F in diet
tea (shouldn’t give to children or pregnant women), coffee, canned fish with bones
what is the most active form of iodine in the human body?
T3 (triiodothyrine)
what is the characterizing symptom of copper poisoning?
metallic taste
what is NOT a sign of iodine deficiency? a. Fatigue
b. Goiter
c. Rachitic rosary
d. Weight gain
e. Sensitivity to cold
rachitic rosary
which is not a symptom of iodine deficiency in newborns and infants?
husky voice
which is the best measure to asses copper status?
serum ceruloplasmin (indicates what is available not just total Cu, it’s an enzyme that DEPENDS on Cu for its activity)
