FA Bioichem 3 vit

  1. (thiamine: TPP)
  2. riboflavin: FAD, FMN
  3. niacin: NAD+
  4. pantothenic acid: CoA
  5. pyridoxine: PLP
  6. Biotin
  7. (folate)
  8. cobalamin
  9. (ascorbic acid)
  10. Vit A Used to treat
    measles and AML, subtype M3.
    Night blindness (nyctalopia); dry, scaly skin(xerosis cutis); alopecia; corneal degeneration(keratomalacia); immune suppression.
  12. Vit A EXCESS
    Arthralgias, skin changes (e.g., scaliness), alopecia, cerebral edema, pseudotumor cerebri, osteoporosis, hepatic abnormalities.Teratogenic (cleft palate, cardiac abnormalities), so a (-) pregnancy test and reliable contraception are needed before isotretinoin is prescribed for severe acne
  13. Vitamin B1 (thiamine)FUNCTION
    In thiamine pyrophosphate (TPP), a cofactor for several dehydrogenase enzyme
  14. thiamine pyrophosphate (TPP), a cofactor for several dehydrogenase enzyme reactions:
    • Think ATP: α-ketoglutarate dehydrogenase,Transketolase, and Pyruvate dehydrogenaseƒƒ
    • -Transketolase (HMP shunt)ƒƒ
    • -Pyruvate dehydrogenase (links glycolysis to TCA cycle)
    • -ƒ α-ketoglutarate dehydrogenase (TCA cycle)ƒƒ

    -Branched-chain ketoacid dehydrogenase
  15. Vitamin B1 (thiamine) DEFICIENCY
    Impaired glucose breakdown Ž ATP depletion worsened by glucose infusion; highly aerobic tissues (e.g., brain, heart) are affected first.Wernicke-Korsakoff syndrome and beriberi.Seen in malnutrition and alcoholism (2° tomalnutrition and malabsorption).
  16. Vitamin B1 (thiamine) DEFICIENCY  Diagnosis
    Diagnosis made by inc in RBC transketolase activity following vitamin B1 administration.
  17. Wernicke-Korsakoff syndrome
    confusion,ophthalmoplegia, ataxia (classic triad) + confabulation, personality change, memory loss (permanent). Damage to medial dorsal nucleus of thalamus, mammillary bodies
  18. Dry beriberi
    polyneuritis, symmetrical muscle wasting.
  19. Wet beriberi
    high-output cardiac failure(dilated cardiomyopathy), edema
  20. Vitamin B2 (riboflavin)FUNCTION
    • FAD and FMN are derived from riboFlavin(B2 = 2 ATP).
    • Component of flavins FAD and FMN, used as cofactors in redox reactions, e.g., the succinate dehydrogenase reaction in the TCA cycle.
  21. Vitamin B2 (riboflavin) DEFICIENCY
    • The 2 C’s of B2.
    • Cheilosis (inflammation of lips, scaling and fissures at the corners of the mouth), Corneal vascularization.
  22. Vitamin B3 (niacin)FUNCTION
    • NAD derived from Niacin (B3 = 3 ATP). 
    • Constituent of NAD+, NADP+ (used in redox reactions). Derived from tryptophan. Synthesis requires vitamins B2 and B6. Used to treat dyslipidemia; lowers levels of VLDL and raises levels of HDL.
  23. Vitamin B3 (niacin) DEFICIENCY
    Glossitis. Severe deficiency leads to pellagra,which can be caused by Hartnup disease( tryptophan absorption), malignant carcinoid syndrome ( tryptophan metabolism),and isoniazid ( vitamin B6).
  24. Symptoms of pellagra:
    Diarrhea, Dementia (alsohallucinations), Dermatitis (e.g., Casal necklace or hyperpigmentation of sun-exposedlimbs).
  25. Vitamin B3 (niacin) EXCESS
    Facial flushing (induced by prostaglandin, not histamine), hyperglycemia, hyperuricemia.
  26. Vitamin B5 (pantothenate) FUNCTION
    • B5 is “pento”thenate
    • Essential component of coenzyme A (CoA,a cofactor for acyl transfers) and fatty acid synthase.
  27. Vitamin B5 (pantothenate) DEFICIENCY
    Dermatitis, enteritis, alopecia, adrenal insufficiency.
  28. Vitamin B6 (pyridoxine) FUNCTION
    Converted to pyridoxal phosphate, a cofactor used in transamination (e.g., ALT and AST),decarboxylation reactions, glycogen phosphorylase. Synthesis of cystathionine, heme, niacin,histamine, and neurotransmitters including serotonin, epinephrine, norepinephrine, dopamine,and GABA.
  29. Vitamin B6 (pyridoxine)DEFICIENCY
    Convulsions, hyperirritability, peripheral neuropathy (deficiency inducible by isoniazid and oral contraceptives), sideroblastic anemias due to impaired hemoglobin synthesis and iron excess.
  30. Vitamin B7 (biotin)FUNCTION
    • Cofactor for carboxylation enzymes (which adda 1-carbon group):
    • -Pyruvate carboxylase: pyruvate (3C)Ž -->oxaloacetate (4C)ƒƒ
    • -Acetyl-CoA carboxylase: acetyl-CoA (2C)Ž --> malonyl-CoA (3C)ƒƒ
    • -Propionyl-CoA carboxylase: propionyl-CoA(3C) -->Ž methylmalonyl-CoA (4C)
  31. what in egg white binds to biotin?
    “Avidin in egg whites avidly binds biotin.”
  32. Vitamin B7 (biotin)DEFICIENCY
    Relatively rare. Dermatitis, alopecia, enteritis.Caused by antibiotic use or excessive ingestion of raw egg whites.
  33. Vitamin B9 (folic acid)FUNCTION
    Converted to tetrahydrofolate (THF), a coenzyme for 1-carbon transfer/methylation reactions.Important for the synthesis of nitrogenous bases in DNA and RNA.
  34. Vitamin B9 (folic acid) Absorbed
    Absorbed in jejunum.
  35. Vitamin B9 (folic acid) DEFICIENCY
    Macrocytic, megaloblastic anemia;hypersegmented polymorphonuclear cells(PMNs); glossitis; no neurologic symptoms(as opposed to vitamin B12 deficiency). Labs: high homocysteine, normal methylmalonica cid. Most common vitamin deficiency inthe United States. Seen in alcoholism and pregnancy.
  36. B9 Deficiency can be caused by several drugs such as?
    Deficiency can be caused by several drugs (e.g.,phenytoin, sulfonamides, methotrexate).Supplemental maternal folic acid in early pregnancy decreases risk of neural tube defects.
  37. Vitamin B12 (cobalamin)FUNCTION
    Cofactor for homocysteine methyltransferase(transfers CH3 groups as methylcobalamin)and methylmalonyl-CoA mutase.
  38. Vitamin B12 (cobalamin) DEFICIENCY
    Macrocytic, megaloblastic anemia;hypersegmented PMNs; paresthesias,and subacute combined degeneration(degeneration of dorsal columns, lateral corticospinal tracts, and spinocerebellar tracts)due to abnormal myelin. Associated with serum homocysteine and methylmalonicacid levels. Prolonged deficiency Ž irreversiblenerve damage.
  39. Diphyllobothrium latum can give what vit def?
  40. Vitamin C (ascorbic acid) FUNCTION
    Antioxidant.Also facilitates iron absorption by reducing it to Fe2+ state.Necessary for hydroxylation of proline andlysine in collagen synthesis.Necessary for dopamine β-hydroxylase, which converts dopamine to NE.
  41. Vitamin C (ascorbic acid)DEFICIENCY
    Scurvy—swollen gums, bruising, hemarthrosis,anemia, poor wound healing, perifollicular and subperiosteal hemorrhages, “corkscrew”hair.Weakened immune response.
  42. Vitamin C (ascorbic acid) EXCESS
    Nausea, vomiting, diarrhea, fatigue, calcium oxalate nephrolithiasis. Can  risk of iron toxicity in predisposed individuals(e.g., those with transfusions, hereditaryhemochromatosis).
  43. Ancillary treatment for methemoglobinemia
    with vit C ; Ancillary treatment for methemoglobinemia by reducing Fe3+ to Fe2+.
  44. Vitamin D FUNCTION
    inc intestinal absorption of calcium andphosphate,  bone mineralization.
  45. vit D2
    ergocalciferol—ingested from plants
  46. vit D3
    cholecalciferol—consumed in milk,formed in sun-exposed skin (stratum basale). 25-OH D3 = storage form. 1,25-(OH)2 D3 (calcitriol) = active form.
    Rickets  in children (bone pain and deformity), osteomalacia in adults (bone pain and muscle weakness), hypocalcemic tetany.Breastfed infants should receive oral vitaminD. Deficiency is exacerbated by low sun exposure, pigmented skin, prematurity.
  48. Vit D EXCESS
    Hypercalcemia, hypercalciuria, loss of appetite,stupor. Seen in sarcoidosis ( activation ofvitamin D by epithelioid macrophages).
  49. Vitamin E (tocopherol/tocotrienol)FUNCTION
    Antioxidant (protects erythrocytes and membranes from free radical damage).
  50. Vitamin E (tocopherol/tocotrienol)DEFICIENCY
    • Hemolytic anemia, acanthocytosis,muscle weakness, posterior column and spinocerebellar tract demyelination.
    • Neurological presentation may appear similarto vitamin B12 deficiency, but withoutmegaloblastic anemia, hypersegmentedneutrophils, or high serum methylmalonic acidlevels.
  51. Vitamin K FUNCTION
    Cofactor for the γ-carboxylation of glutamic acid residues on various proteins required for blood clotting. Synthesized by intestinal flora.
    Neonatal hemorrhage with high PT and high aPTT but normal bleeding time (neonates havesterile intestines and are unable to synthesizevitamin K). Can also occur after prolonged use of broad-spectrum antibiotics.
  53. Zinc FUNCTION
    Essential for the activity of 100+ enzymes. Important in the formation of zinc fingers (transcriptionfactor motif).
  54. Zinc def
    Delayed wound healing, hypogonadism, low adult hair (axillary, facial, pubic), dysgeusia, anosmia,acrodermatitis enteropathica. May predispose to alcoholic cirrhosis.
  55. acrodermatitis enteropathica
    autosomal recessive metabolic disorder affecting the uptake of zinc, characterized by periorificial (around the natural orifices) and acral (in the limbs)dermatitis, alopecia (loss of hair), and diarrhea.
Card Set
FA Bioichem 3 vit