Chapter 2: vitamins, minerals, trace elements Flashcards
Which vitamin is the cofactor for PTH?
Vitamin A
PTH
causes osteoclast activity: Ca up and P down
If Ca and P are both down, which vitamin is missing?
Vitamin D (allows more Ca to be absorbed)
Which vitamins needed for night vision?
Vitamin A
Vitamin for CSF production?
Vitamin A
For which pts should we give Vitamin A?
- Measles (regenerate epithelium of lung)
- Cancer t(15,17)
- infections that destroy cells
- Burn pts
What is the most common cause of free radical formation?
infection, mcc viruses
Which cells make free radicals and using which enzyme?
neutrophils via NADPH oxidase
Too much vitamin A?
- hyperparathyroidism (Ca up and get moans, groans and stones) 2. pseudotumor cerebri CSF up, brain ventricles dilate causing headache and papilledema
Headache with Papilledema steps to diagnosis
- Rule out mass (non contrast CT)
- rule out infection (LP)
Tx for Pseudotumor Cerebri
1.discontinue Vitamin A
2. if acute: serial lumbar puncture 30cc/24hours
3.chronic: weight loss, CA inhibitor: acetazolamide or mannitol
carbonic anhydrase inhibitor
acetazolamide
criteria for bariatric surgery
BMI greater than 40
BMI greater than 35 with cormorbidity
BMI greater than 30 with 2 comorbidities
Thiamine important for 4 enzymes
- pyruvated dehydrogenase
2.alpha-ketoglutarate dehydrogenase
3.branched chain amino acid dehydrogenase
4.transketolase (pentose phosphate pathway)
All use TPP (thiamine pyrophospate)
which organs use thiamine?
brain uses transketolase; heart uses dehydrogenases
Where is the Wernicke area?
posterior temporal lobe
What is Wernicke’s function?
receive spoken or written language
Wernicke’s aphasia?
receptive aphasia
Wernicke-Korsakoff
from alcoholism: mamillary bodies involved; confabulation; unable to move short term memory into long term memory
What is beriberi and what are the two types?
Heart gives out from massive dilation; dry beriberi (until you have heart failure); wet beriberi (fluid in lungs, massive ventricular dilation) from Vita B1 deficiency
What is a sign of B2 deficiency?
angular cheilosis
What is B2 name?
riboflavin
What is B2 used for?
for cofactors (FAD)
5 enzymes needed by pyruvated dehydrogenase, a-ketoglutarate dehydrogenase and branched chain AA dehydrogenase
Tender Loving Care For Nancy:
Thiamin
Lipoic Acid
CO-A (B5)
FAD (B2)
NAD (B1)
What AA is the precursor to Niacin?
Tryptophan
4 Ds of Niacin deficiency
diarrhea, dermatitis, dementia, and death (Pellagra)
What is the problem in Hartnup’s disease?
defective renal transport of tryptophan, causing tryptophan to leak into urine (presents like Pellagra)
Besides Niacin, tryptophan also is needed to make what?
serotonin
another disease that uses up tryptophan
carcinoid syndrome, serotonin excreted out rapidly, using a lot of tryptophan
Niacin supplements can be used for which disorder?
hypertriglyceridemia
What are the side effects of using niacin supplements?
flushing, itching due to release of prostaglandins; insulin resistance (because blocks insulin receptors); gout (competes with uric acid)
What is the acute management of gout?
indomethacin (inhibits COX 1/2)
What is the most effective treatement for gout?
colchicine (blocks tubules); could cause renal failure
Which gout drug blocks xanthine oxidase?
Allopurinol
Which gout drug is a recombinant of urate oxidase (uricase) that metabolizes uric acid
Rasburicase
Which gout drug block reabsorption of uric acid?
Probenecid
Which vitamin is needed for all liver transaminases?
B6
Which vitamin is needed to make heme?
B6
Which TB drug must we supplement B6 (pyridoxine)?
Isoniazid (INH)
DOC for chronic neuropathy
TCA
MOA for TCA
blocks reuptake of catecholamine (levels rise); block Na, block alpha 1, antihistiminc
If heart disease which drug for neuropathy?
gabapentin
If shooting/stabbing neuropathy?
carbamazepine (blocks Na/Ca channel
What is the first vitamin to run out when a pt has rapidly dividing cells?
folate
When are cells rapidly dividing?
0-2 years
4-7 years
puberty
pregnancy
folate function
makes tetrahydrofolate (THF) that makes thymidine of DNA
anemia of folate deficiency
megaloblastic anemia
What could be complications of B9 deficiency in pregnancy?
neural tube defects
Vitamin B12 is needed by which two enzymes?
Homocysteine methyltransferase (makes THF)
and Methyl Malonyl CoA mutase (recycles odd FA to make myelin, so deficiency causes neuropathy)
How to distinguish B9 from B12 deficiency in megaloblastic anemia?
- B12 has neuropathy
- B9 very rapidly depleted; B12 takes years to deplete
3.B12 def. will cause methylmalonic acid in urine to rise
MCC of pernicious anemia in the US
Type A gastritis
What is vita C used for?
hydroxylates proline and lysine in collagen and elastin
Where does hydroxylation occur in a cell?
RER
sign of vitamin C deficiency
bleeding from hair follicles and gums
Why is it best to drink orange juice with iron supplements?
Vitamin C protects iron from being oxidized in GI tract
Vitamin D deficiency in children
rickets
Vitamin D deficiency in adults
osteomalacia
If a girl has rickets and vitamin D doesn’t correct it, what should you suspect?
Vitamin D resistant rickets
(X linked dominant) Dad’s give daughters ; defective renal reabsorption of phosphorus
Labs seen in Vitamin D resistant rickets?
Low calcium, low phosphorus even with Vita D supplementation.
X-linked dominant diseases
- Vita D resistant rickets
- pyruvate dehydrogenase deficiency
3.pseudohypothyroidism
What is the main antioxidant in blood?
Vitamin E
What is biotin necessary for?
carboxylation
What is Vita K used for?
gamma carboxylation (adds third gamma carboxyl group to Vita K dependent clotting factors
What are Vita K dependent clotting factors?
10, 9, 7, 2 Protein C and S
What drug blocks all Vita K clotting factors?
Warfarin
Why does warfarin cause clots at first?
Protein C (thrombolytic) is the first factor to lose its function, so there may be local clotting.
Why do we give heparin before warfarin?
to prevent clotting
How many days is the heparin bridge?
two days
If you don’t want 2 day heparin bridge which drugs can you consider?
apixaban, rivaraxaban (direct factor X inhibitors)
Anticoagulant for pregnant women?
LMWH until 9 months switch to unfractioned heparin
What do you give first for venous clots?
heparin
What do we check when a pt on warfarin?
PT
If PT is too high in warfarin pt?
vita K complex IM; if bleeding acutely, prothrombin complex or FFP
duration of warfarin treatment
1st clot with known cause, 3 months; second time with know cause, 12 months; 3rd time or if ever the cause is unknown, lifetime
MCC genetic spontaneous venous clot
Factor V Leiden mutation
Treatment of Factor V Leiden mutation?
lifetime warfarin
desired INR with warfarin
2-3
desired INR with warfarin for prosthetic valve pts?
2.5 to 3.5
What factors does heparin block?
thrombin, and intrinsic pathway (9,10, 11, 12)
What lab do we follow with heparin?
PTT
heparin toxicity antidote
protamine sulfate; acutely bleeding FFP
SE of heparin
bleeding, hyperlipidemia due to homorne sensitive lipase (milky white plasma); HIT1 from platelet clumping within first 2 days; HIT2 after day three
HIT2 cause
Heparin acts as hapten on PLT causing antibodies to form; attack on PLT causing inflammation and vasculitis
HIT2 treatment
switch to Argatroban (block thrombin directly); or fondaparinux (factor Xa inhibitor)
What can we do if pt. has contraindications to heparin but has venous clots?
IVC filter
4 cephalosporins inhibit vita K?
cefamandole, cefotetan, moxalactam, cefoperazone
Which three vitamins need to be supplemented for pregnancy?
folate, Ca, Iron
cofactor for all kinases
magnesium
cofactors of PTH
vita A and magnesium
Why should we give K bolus with Magnesium
K and Mg share cotransport protein
Which mineral is needed for hair, skin, sperm and taste buds?
zinc
Which mineral is needed by complex IV in electron transport chain?
Copper
Which mineral is needed by lysine oxidase in formation of collagen?
copper
Which disease is caused by ceruloplasmin deficiency?
Wilson’s Disease
What does ceruloplasmin do?
transports copper from liver to duodenum for excretion; if deficient, cannot excrete copper and copper will accumulate in liver (cirrhosis); brain (basal ganglia) and cornea (Keyser-Fleischer rings)
What is DOC for Wilson’s?
penicillamine ( cannot use if allergic to penicillin and may cause drug-induced lupus
Which movement disorder is caused by trinucleotide repeats?
Huntington’s
MCC of death in Huntington’s
suicide
Which area of brain is affected by Huntington’s?
caudate nucleus
DOC for Huntington’s?
antipsychotics (dopamine blocker)
5 diseases that have trinucleotide repeats
- Huntington’s
- Fragile X
- mytonoic dystrophy
- Freidrich’s ataxia
5.Prader-Willi (5% trinucleotide repeats)
What gene is involved in Wilson’s?
ATP7B
What gene is involved in Menke’s?
ATP7A
What trace element if deficient may cause DM2?
chromium
What is the inheritance pattern for structural proteins?
Autosomal dominant
What is the inheritance pattern for enzymes?
Autosomal Recessive
What is it called if you inherited the gene but don’t have the disease?
incomplete penetrance
What is it called when many members of a family have the defective gene but have different problems?
variable expression