Vitamin Flashcards
vitB1: aka
thiamine
thiamine: aka
vitB1
vitB1: fx
thiamine pyrophosphate (TPP) –> cofactor for several deH rxns –> “ATP”:
- a-ketoglut deH (TCA)
- transketolase (HMP shunt)
- pyruvate deH (link glycolysis to TCA)
- branched chain ketoacid deH
vitB1 def: pathophys
impaired glucose brkdown –> ATP deplete:
- highly aerobic tissues affected 1st –> brain, heart
- worsened by glucose infusion
vitB1 def: leads to
- Wernicke-Korsakoff
- beriberi
Wernicke-Korsakoff synd: pathophys
damage:
- medial dorsal nucleus of thalamus
- mammilary bodies
Wernicke-Korsakoff synd: ssx
- triade: confuse, ophthalmoplegia, ataxia
- confabulation
- personality change
- memory loss (permanent)
vitB2: aka
riboflavin
riboflavin: aka
vitB2
vitB2: fx
FAD & FMN –> cofactor for redox rxn –> succinate deH (TCA)
vitB2 def: ssx
- cheilosis
- corneal vascularization
vitB3: aka
niacin
niacin: aka
vitB3
vitB3: how much ATP?
3
vitB2: how much ATP?
2
vitB3: derived from?
tryptophan
vitB3: syn requires what other vit?
- vitB2
- vitB6
vitB3 def: cause
- Hartnup dz: decrease tryptophan absorb
- malig carcinoid synd: increase Trp metab
- isoniazid: decrease vitB6
vitB3 def: leads to
pellagra:
- diarrhea
- dementia
- dermatitis
vitB5: aka
pantothenate
pantothenate: aka
vitB5
vitB6: aka
pyridoxine
pyridoxine: aka
vitB6
vitB6: fx
- cofactor for glycogen phosphorylase
- NT syn: serotonin, Epi, NE, dopamine, GABA
- syn: cystathione, heme, niacin, histamine
vitB5 def: cause
- isoniazid
- OCP
vitB7: aka
biotin
biotin: aka
vitB7
vitB7 def: cause
- abx
- excess ingest raw egg white: avidin –> bind biotin
vitB9: aka
folic acid
folic acid: aka
vitB9
vitB9: fx
syn of N bases in DNA/RNA
vitB9: absorbed where?
jejunum
vitB9 def: ssx
- macrocytic megaloblastic anemia
- hypersegmented PMNs
- glossitis
no neuro ssx (unlike vitB12 def)
vitB9 def: lab findings
- increased homocysteine
- normal methylmalonate
what is the most common vit def in US?
vitB9
vitB9 def: who?
- alcoholic
- preg
vitB12: aka
cobalamin
cobalamin: aka
vitB12
vitB12: fx
cofactor:
- homocysteine methyltransferase
- methylmalonyl-CoA mutase
homocysteine methyltransferase: rxn
homocysteine + THF-CH3 –> methionine + THF –> CH3 for anabolic rxns
methylmalonyl-CoA mutase: rxn
methylmalonyl CoA –> succinyl CoA –> TCA, myelin syn, heme
methylmalonyl CoA: comes from?
- ff w odd #C
- branched chain aa
vitB12: source
- microorg –> animal products
- lrg reserved pool in liver
vitB12 def: cause
- insuff intake: vegan
- malabsorb: sprue, enteritis, Diphyllobothrium latum
- no IF: pernicous anemia, gastric bypass surg
- no terminal ileum: Crohn
vitB12 def: ssx
- macrocytic megaloblastic anemia
- hypersegmented PMNs
- neuro ssx
vitB12 def –> neuro ssx: pathophys
no succinyl CoA –> impair myelin syn –> degen of:
- dorsal column
- lat corticospinal
- spinocerebellar
vitB12 def: lab findings
increased:
- homocysteine
- methylmalonic acid
vitC: fx
- iron absorb
- collagen syn
- dopamine B-hydroxylase: dopamine –> NE
scurvy: ssx
- swollen gums
- bruise
- hemarthrosis
- anemia
- poor wound heal
- perifollicular, subperiosteal hemorrhage
- “corkscrew” hair
vitD def: leads to
- child –> rickets: bone pain, deformity
- adult –> osteomalacia: bone pain, muscle weak
vitE: fx
antioxidant –> protect RBC & membranes from ROS damage
vitE def: ssx
similar to vitB12 def –> except no:
- megaloblastic anemia
- hyperseg PMN
- increased methylmalonic acid
vitK def: lab findings
- increased PT, PTT
- normal bleeding time