Vitamins
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47 terms
Terms | Definitions |
|---|---|
 B1 (thiamine) - part of what complex? | TPP (thiamine pyrophosphate) |
| B1 (thiamine) - cofactor for what enzymes? | pyruvate dehydrogenase (glycolysis) alpha-ketoglutarate dehydrogenase (TCA cycle) transketolase (HMP shunt) branched chain AA dehydrogenase |
| B1 (thiamine) - people you see it with? | alcoholics (secondary to malnutrition and malabsorption) and malnourished |
| B1 (thiamine) - diseases of deficiency | wernicke-korsakoff syndrome, beriberi (wet and dry) |
| B2 (riboflavin) - function | cofactor for oxidation and reduction (e.g., FADH2) |
| B2 (riboflavin) - deficiency | Cheilosis, Corneal vascularization |
| B3 (niacin) - function | constituent of NAD+,NADP+ |
| B3 (niacin) - derived from what amino acid? | tryptophan |
| B3 (niacin) - what vitamin is needed for synthesis? | B6 (pyridoxine) |
| B3 (niacin) - deficiency | Glossitis, Pellagra (Dermatitis, Diarrhea, Dementia) |
| B3 (niacin) - causes of deficiency | Hartnup disease (decreased tryptophan absorption), malignant carcinoid syndrome (increased tryptophan metabolism), and INH (decreased B6) |
| B3 (niacin) - excess | facial flushing (offset by aspirin) |
| B5 (pantothenate) - function | part of CoA and fatty acyl synthase |
| B5 (pantothenate) - deficiency | dermatitis, enteritis, alopecia, adrenal insufficiency |
| B6 (pyridoxine) - converted into what? why? | pyridoxal phosphate, a cofactor used in transamination (e.g., ALT, AST), decarboxylation reactions, glycogen phosphorylation, and heme synthesis (ALA synthase) |
| B6 (pyridoxine) - required for synthesis of what vitamin from what amino acid? | niacin from tryptophan |
| B6 (pyridoxine) - deficiency | convulsions, hyperirritability, peripheral neuropathy |
| B6 (pyridoxine) - what drugs induce deficiency? | INH and oral contraceptives |
| B12 (cobalamin) - function | cofactor for homocystein methyltransferase (transfers methyl groups as methylcobalamin) and methylmalonyl-CoA mutase |
| B12 (cobalamin) - foods found in | animal products |
| B12 (cobalamin) - can humans make it? | no; only microorganisms |
| B12 (cobalamin) - size of reserve | very large reserve stored in liver (years worth) |
| B12 (cobalamin) - causes of deficiency | malabsorption (sprue, enteritis, Diphyllobothrium latum), lack of intrinsic factor (pernicious anemia, gastric bypass surgery), absence of terminal ileum (Crohn's disease), or veganism |
| B12 (cobalamin) - test for nature of deficiency | Schilling's test |
| B12 (cobalamin) - what does deficiency do? | macrocytic, megaloblastic anemia; neurologic symptoms (paresthesias, subacute combined degeneration) due to abnormal myelin; irreversible nerve damage if prolonged deficiency |
| B12 (cobalamin) - sign of deficiency (urine) | methylmalonyl in urine |
| Folic acid - function | converted to THF, a coenzyme for 1 carbon transfer/methylation reactions; important for synthesis of nitrogenous bases in DNA and RNA |
| Folic acid - source | Folate is from Foliage |
| Folic acid - reserve size? | small reserve in liver. must eat green leaves regularly |
| Folic acid - deficiency | macrocytic, megaloblastic anemia; no neurologic symptoms; MOST COMMON in USA |
| Folic acid - when is deficiency common? | alcoholism and pregnancy |
| folic acid - drugs that cause deficiency? | several! (phenytoin, sulfonamides, MTX) |
| folic acid - why take early in pregnancy | prevent neural tube defects |
| common sign for folic acid, B12, or B6 deficiency | hyperhomocysteinemia |
| S-adenosyl-methionine | ATP + methionin = SAM; transfers methyl units; regeneration of SAM is dependent on both B12 and folate |
| Biotin - function | cofactor for carboxylation enzymes -pyruvate carboxylase (forms oxaloacetate) -acetyl-CoA carboxylase (forms malonyl-CoA) -propionyl-CoA carboxylase (forms methylmalonyl-CoA) |
| Biotin - deficiency | rare. causes dermatitis, alopecia, enteritis. |
| Biotin - main causes of deficiency | antibiotic use or excessive ingestion of raw eggs (avidin in egg whites binds it) |
| Vitamin C - function | -antioxidant. -facilitates iron absorption (keeps it reduced) -hydroxylates proline and lysine on collagen -necessary for dopamin beta-hydroxylase which converts dopamine to NE |
| Vitamin C - deficiency | swollen gums, bruising, anemia, poor wound healing |
| Vitamin C - sources | fruits, veggies, limes |
| Vitamin E - function | antioxidant (protects erythrocytes and membranes from free-radical damage) |
| Vitamin E - deficiency | fragile erythryocytes (hemolytic anemia), muscle weakness, neurodysfunction |
| Vitamin K - function | gamma carboxylation of glutamic residues on clotting proteins |
| Vitamin K - synthesis site | intestines by flora |
| Zinc - function | zinc fingers. function of 100+ enzymes |
| Zinc - deficiency | delayed wound healing, hypogonadism, decreased adult hair (axillary, facial, pubic). may predispose to alcoholic cirrhosis |
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