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22 Cards in this Set
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- Back
- 3rd side (hint)
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What are the fat soluble vitamins?
Causes of deficiencies? |
Vitamins A, D, E, K
Absorption dependent on gut [ileum] and pancreatic function Toxicity more common than for water-soluble vits. [these accumulate in fat] |
Causes of deficiencies:
Malabsorption syndromes: - cystic fibrosis - sprue - mineral oil intake |
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What are the water solube vitamins?
Which ones do not washout easily? |
B1 (thiamine: TPP)
B2 (riboflavin: FAD, FMN) B3 (niacin: NAD+) B5 (pantothenic acid: CoA) B12 (cobalamin) C (ascorbic acid) Biotin Folate |
All wash out easily from body except B12 and Folate -- stored in liver
B complex deficiencies all cause dermatitis, glossitis, diarrhea |
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Vitamin A (retinol)
Function? Deficiency? Excess? |
Function:
- Antioxidant - constituent of visual pigments (retinal) - wrinkles, acnue - normal differentiation of epithelial cells into specialized tissues (pancreatic cells, mucus-secreting cells) - prevents squamous metaplasia - USED TO TREAT: measles, AML type M3 |
Deficiency: night blindness, dry skin
Excess: arthralgias, fatigue, headaches, skin changes, sore throat, alopecia. TERATOGENIC - cleft palate, cardiac abnormalities. Can cause pseudotumor cerebri |
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Vitamin B1 (thiamine)
Function? Deficiency? |
Cofactor for several enzymes in decarboxylation reactions [in Thiamine pyrophosphate]:
- pyruvate dehydrogenase (glycolysis) - alpha-ketoglutarate dehydrogenase (TCA) - Transketolase (HMP shunt) - branched-chain AA dehydrogenase |
Deficiency:
- impaired glucose breakdown causing ATP depletion; highly aerobic tissues like brain and heart are affected first Wernicke-Korsakoff syndrome and berberi - seen in malnutrition as well as alcoholism |
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Dry beriberi?
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Polyneuritis, symmetrical muscle wasting
Vit B1 (thiamine) deficiency |
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Wet berberi?
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high-output cardiac failure (dilated cardiomyopathy), edema
Vit B1 (thiamine) deficiency |
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Wernicke-Korsakoff
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confusion, ophthalmoplegia, ataxia (classic triad) + confabulation, personality changes, memory loss (permanent)
Damage to mammillary bodies and medial dorsal nucleus of thalamus Exacerbated by glucose infusion! |
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Vitamin B2 (riboflavin)
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Cofactor in oxidation and reduction (FADH2)
Makes 2 ATP birth FAD |
Deficiency:
Cheilosis (inflammation of lips, scaling, and fissures at corners of mouth) Corneal vascularization |
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Vitamin B3 (niacin)
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constituent of NAD, NADP+
Derived from tryptophan. Requires B6 for synthesis Increases HDL |
Deficiency:
Glossitis, pellagra [Hartnup disease, malignant carcinoid tumor syndrome, INH ->lowB6] Excess: facial flushing |
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Vitamin B5 (pantathenate)
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component of CoA [cofactor for acyl transfers] and fatty acid synthase
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Deficiency:
dermatitis, enteritis, alopecia, adrenal insufficiency |
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Vitamin B6 (pyridoxine)
Function? Deficiency? |
Active: pyridoxal phosphate -- cofactor for transamination, decarboxylation, glycogen phosphorylase
Synthesis of 1) cystathionine 2) heme 3) niacin 4) GABA |
Deficiency
convulsions, hyperirritability, peripehral neuropathy [induced by INH or OCPs], sideroblastic anemias [impaired Hb synthesis and Fe excess] |
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Vitamin B12
Function? Deficiency? |
Cofactor for homocysteine methyltransferase and methylmalonyl-CoA synthase
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D: Macrocytic, megaloblastic anemia, neurologic sx (destruction of posterolateral spinal cord tracts), glossitis.
Due to vegetarianism, malabsorption, Diphyllobothrium latum, dec intrinsic factor (pernicious anemia, no terminal ileum (crohns) Use Shilling test to determine etiology |
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Folic Acid
Function? Deficiency? |
Tetrahydrofolate (active) is coenzyme for 1-carbon transfer/methylation rxns
synthesis of nitrogenous bases in DNA / RNA |
D: Macrocytic, megoblastic anemia, no neurological.
Caused by: phenytoin, sulfonamides, MTX -- alcoholism, pregnancy Supplement in early pregnancy to reduce NTDs |
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Biotin
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Cofactor for carboxylation enzymes:
1) pyruvate carboxylase 2) Acetyl-CoA carboxylase 3) propionyl-CoA carboxylase |
D: Dermatitis, enteritis.
Due to antibiotic use, ingestion of raw eggs. |
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Vitamin C (ascorbic acid)
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Function:
- iron absorption, keeps in reduceds tate - hydroxylation of proline and lysine in collagen synthesis - dopamine beta-hydroxylase to convert dopamine to NE |
D: Scurvy- swollen gums, bruising, anemia, poor wound healing.
Weakened immune response Excess: nausea, vomiting, diarrhea, fatigue, sleep problems; increased iron toxicity in predisposed individuals [frequent transfusions, hereditary hemachromatosis] |
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Vitamin D
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D2= ergocalciferol (milk)
D3= cholecalciferol (sun) 25-OH D3 = Storage 1,25 0H2 D3= Active form |
D: Rickets in kids. Osteomalacia in adults, hypocalcemic tetany. LOW in breast milk
E: Hypercalcemia, loss of appetite, stuper. Sarcoidosis: epithelioid macs convert VD to active form. |
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Vitamin E
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Antioxidant (protects erythrocytes and membranes from free-radicals)
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D: Increased fragility of erythrocytes, neurodysfunction- spinocerebellar degeneration --> similar to Fred Ataxia
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Vitamin K
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K dependent clotting factors are II, VII, IX, X, PT C and S.
Catalyzes gamma-carboxylation of glutamic acid residues. Synthesized in intestinal flora |
Neonatal hemorrhage. Normal BT, inc PT, inc PTT.
Also after broad-spectrum antibiotic use NOT in breast milk |
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Zinc
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Essential for activity of 100+ enzymes
Formation of zinc fingers (transcription factor motif) |
D: delayed wound healing, hypogonadism, dec adult hair (axillary, facial, pubic) may predispose to alcoholic cirrhosis.
Acrodermatitis enteropathica - rash around eyes, nose, mouth, anus |
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Kwashiorkor- malnutrition-> skin lesions, edema, liver malfunction, fatty change, anemia. Clinical setting of severe trauma, burns, sepsis.
Serum albumin <2.8gm/dL Poor prognosis |
Protein-lacking diet
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Marasmus-tissue and mm wasting, loss of subcutaneous fat and variable edema.
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Starvation- lacking calories
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S-adenosyl-methionine (SAM)
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Transfers methyl units
Required for conversion of NE to Epinephrine |
Regeneration of methionine and SAM is dependent on B12 and folate
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