Vitamin A retinol.
Antioxidant; component of visual pigments.
Deficiency --> night blind
B1 in TPP (cofactor for several enz):
1. PDH (glycolysis)
2. alphaKG DH (TCA)
3. Transketolase (HMP shunt).
4. branched chain AA DH.
Defic --> Wernicke Korsakoff, "Ber1ber1".
See defic in MALNUTRITION and ALCOHOLISM.
cofactor in REDOX. (FADH2).
FAD and FMN are derived from riboflavin.
Deficient B2--> 2C's --> cheilosis (lips inflamm),
and corneal vascularization.
B2 = 2 ATP!
B3 Niacin; derived from Trp.
synth REQUIRES B6.
consitit. of NAD+ and NADP+ (REDOX RXNS).
Deficiency --> Pellagra (dermatitis, diarrhea, dementia
= DDD for B3).
deficiency CAUSED by Hartnup's (Trp absorption
EXCESS = niacin flush.
B3 = 3 ATP
Pantothen-A is in CoA!! (cofactor for ACYL TRANSFERS)
and FATTY ACID SYNTHAS.
deficiency = dermatitis, adrenal insuff.
converted to Pyridoxal phosphate --> cofactor in
TRANSAM. RXNS (ALT, AST), DECARBOX, GLYCOGEN
PHOSPHORYLASE, and HEME SYNTH.
** required for synth of niacin from Trp.
cofactor for HOMOCYSTEIN METHYLTRANSFERASE and
defic --> megablastic anemia.
homocyst+N-methylTHF --B12--> Methionine + THF
methylmalonylCoA --B12--> Succinyl-CoA
Folic acid converted to THF (coenzy. for 1C transferse/methylation
synth of bases in DNA and RNA.
defic --> megablastic anemia; seen in ALCHOLISM, and
also def. via drugs (sulfonamides, MTX)
Defic --> convulsions, periph neuropathy.
Biotin cofactor for carboxylation enzymes:
1. Pyruvate carboxylase (pyruvate --> oxaloacetate).
2. acetylCoA carboxylase (acetyl-CoA--> malonylCoA).
3. Propionyl-CoA carboxylase (propionyl-CoA -->
Def RARE --> (dermatitis) caused by antiobiotics or
excessive raw eggs ( Avidin )
Vit C (ascorbate) antioxidant
1. facilitates iron absorb by keeping iron in Fe2+ state
2. proline and lysine hydroxylation.
3. dopamine beta hydroxylase (dopamine --> NE)
Vitamin D 25-(OH)D3 --> storage form
1,25 (oh)2 D3 --> active form.
incrases intestinal P and Ca absorb.
increases bone resorb.
defic --> rickes (kids), osteomalacia (adults).
excess 00> hypercalcemia, see in SARCOIDOSIS.
Vitamin E E for erythrocytes.
antiox; protects eryth's from free radical damage.
defic --> hemolytic anemia.
Vitamin K K for Koag... need for synth of II, VII, IX, X.
gamma carboxylation of glutamic acid in BLOOD CLOT
synth'd by intestinal flora.
defic --> hemmhorage (neonate) increase PT, increase
aPTT; NORMAL BLEEDING TIME.
can happen after antibiotic long term use.
WARFARIN = vitamin K antagonist.
defic --> scurvy