Flashcards in Vitamins Deck (43):
riboflavin: FAD, FMN
pantothenic acid: CoA
fat soluble vitamins
vit A (retinol)
-visual pigments (retinal)
-normal diff of epith cells into specialized tissues
-prevents squamous metaplasia
-tx of measles, AML M3
-in liver (esp polar bears), leafy vegetables, beta-carotene (carrots)
vit A (retinol) deficiency
-bitot spots (dry spots on conjunctiva)
-keratomalacia (wrinkling/clouding of cornea)
vit A (retinol) excess
-arthralgias, fatigue, HA, sore throat
-skin changes (oranging of skin, dry/pruritic skin)
-teratogenic (cleft palate, cardiac abnorm)
-increased ICP (pseudotumor cerebri)
-TPP = active form
-cofactor for enzymes in decarboxylation rxns (pyruvate DH, alpha-ketoglutarate DH, transketolase, branched-chain AA DH)
vit B1 deficiency
-ATP depletion (from impaired glucose breakdown) --> WORSENED w/ glucose infusion
-brain/heart affected first (highly aerobic)
-Dry beriberi (neuritis, symm muscle wasting)
-Wet beriberi (high-output cardiac failure, dilated cardiomyopathy, edema)
-seen in alcoholics, in malnutrition, and in pts on dialysis
-cofactor in oxidation/reduction
-FAD (cofactor for succinate DH + component of ETC complex II)
-FMN (component of ETC complex I)
vit B2 deficiency
-"mouth and eyes"
-cheilosis (inflamm of lips, scaling/fissures @ corners of mouth)
-NAD+/NADP - used in redox rxns
-derived from tryptophan
-synth req B6 + B2
vit B3 deficiency
-**pellagra: (if severe); aka caused by:
-Hartnup dz - decreased tryptophan absorp
-malig carcinoid synd (increased tryptophan metab)
-INH (decreases B6)
vit B3 excess
-component of CoA + fatty acid synthase
vit B5 deficiency
-pyridoxal phosphate = active form
-used in transamination (ALT, AST) and decarboxylation rxns
-cofactor for glycogen phosphorylase
-synth of cystathionine, heme, niacin, histamine, NT (serotonin, epinephrine, NE, GABA)
vit B6 deficiency
-convulsions (bc decreased GABA)
-periph neuropathy (deficiency inducible by INH + oral contraceptives)
-sideroblastic anemias (due to impaired Hb synth and Fe excess) - bc lack of ALA-S enzyme
best enzyme to test B1 deficiency?
"tea and toast" diet deficiency?
vit B2 impt for what enzymes?
-succinate DH (TCA)
-fatty-acyl CoA DH (beta-oxidation)
-glycerol phosphate shuttle
B7 cofactor for?
-pyruvate carboxylase (pyruvate (3C) --> OA (4C)) - used in gluconeogenesis
-acetyl-CoA carboxylase (acetyl-CoA (2C) --> malonyl-CoA (3C)) - used in FA synthesis
-propionyl-CoA carboxylase (propionyl-CoA (3C) --> methylmalonyl-CoA (4C)) - used to metabolize odd-chain FA, Val, Met, Ile, Thr ("VOMIT" pathway)
B7 deficiency caused by? causes?
by avidin in egg whites or AB use
causes dermatitis, alopecia, enteritis; also fasting hypoglycemia (loss of pyruvate carboxylase)
deficiency of B9 seen in?
alcoholics and pregnant pts
also w/ several drugs (phenytoin, sulfonamides, MTX, TMP)
B9 function =?
converted to THF = coenzyme for 1C transfer/methylation rxns
impt for synth/repair of DNA and synth of nitrogenous bases in DNA + RNA
-homocysteine methyltransferase (untraps inactive folate from storage [N5-methyl-THF])
-methylmalonyl-CoA mutase (part of "VOMIT" pathway)
deficiency of vit B12 seen w/?
-malabsorption (enteritis, sprue, Diphyllobothrium latum)
-lack of intrinsic factor
-absence of terminal ileum (Crohn's disese)
labs show what in B12 def?
increased methylmalonic acid and homocysteine levels
SAM and methionine regen depend on?
vit B12 and folate
4 functions of vit C?
-facilitate iron absorption by keeping in in reduced (Fe2+) state
-nec for hydroxylation of proline and lysine in collagen synth
-nec for dopamine-beta-hydroxylase (converts dopamine --> NE)
vit D deficiency seen in patients that:
-have dark skin
vit E function?
protect RBCs and membrane lipids from ROS
vit E deficiency?
-hemolytic anemia (bc increased fragility of RBCs)
-(proximal) muscle weakness
-***posterior column and spinocerebellar tract demyelination (mimics Friedrich's ataxia; ataxia, dysarthria, loss of proprioception/vibratory sense)
-decrease serum phospholipids and cause infertility
vit E tx for?
vit E excess?
hemorrhagic stroke (in adults)
necrotizing enterocolitis (in infants)
vit K function
gamma-carboxylation of glutamic acid residues (put another COO- group)