Nutrition Flashcards
Nutrition
Fat Soluble Vitamins
Fat Soluble: A, D, E, K
Absorption dependent on gut (ileum) and pancreas
More toxic than water soluble bc they can accumulate in fat
Nutrition
Water Soluble Vitamins
Vits B, C
All wash out form body except B9 (folate) and B12 (cobalamin)
Deficiencies result in determatitis, glossitis, diarrhea
B1: Thiamine, B2: riboflavin, B3: niacin, B5: panthothenic acid, B6: pyridoxine,B7: biotin,B9: folate, B12: cobalamin
” T his R eally N ice P ill P uts Vit B in F orm”
Nutrition
Vitamin A
1) Retinol, B-carotene, Retinoic Acid
2) Antioxidant, part of visual pigments, needed for differentiation of epi cells, prevents squamous metaplasia, help treat winkles/acne. Used to treat measles, AML
Def: night blindness, dry skin, esopthalma, keratomalacia,
Excess: arthralgias, fatigue, headaches, skin changes, sore throat,alopegia, TERATOGENIC (clef palate/cardiac abnormalities)
Nutrition
Vitamin B1
1)Thiamine, cofactor for decarboxylation enzymes (pyruvate dehydroganse, alpha-KG dehydrogase, transketolase)
Def : Impaired glucose breakdown, ATP depletion worsened, always give thiamine before glucose
Wernicke-Korsakoff disease
Dry Beriberi - Neuro probs -polyneuritis,muscle wasting, peripheral neuropathy
Wet Beri Beri - cardiac - high output cardiac failure (dilated cardiomyopathy), edema
Nutrition
Vitamin B2
- Riboflavin
- Needed for redox rxns (FAD, FMN)
- Def: cheilosis, corneal vascularization, dermatitis, glossitis
Nutrition
Vitamin B3
-Niacin
-Constituent of NAD+, NADP+, derived from tryptophan, synthesis requires vitB6
-Def: caused by hartnup’s, malignant carcinoid syndrome, and INH (bc you lose vitB6)
Pellagra (dementia, dermatitis, diarrhea)
-Excess: facial flushing
Nutrition
Vitamin B5
Panthothenate, essential component of Coenzyme A and fattyacid synthase
Def: dermatitis, enteritis, alopecia, adrenal insufficiency
Nutrition
Vitamin B6
Pyridoxine
-converted to pyridoxal phosphate, cofactor for transamination, decarboxylation rxns, glycogen phosphorylate
Synthesis of heme,niacin, histamine, NTM (5HT,Epi, NorEpi, GABA)
Def: convulsions, hyperirratability,periph neuropathy, sideroblastic anemias (due to impaired Hgb synthesis/Fe excess)
Nutrition
Vitamin B7
Biotin, Cofactor for carboxylation/CO2 reactions
-Pyruvate carboxylase,acetylCoA carboxylase, Propionyl CoA carboxylase
Def: dermatitis,alopecia, enteritis
Caused by Abx use or excessive ingestion of raw eggs (due to Avidin, which binds biotin)
Nutrition
Vitamin B9
Folic Acid
Converted to (THF), a coenzyme for a -carbon transfer/methylation reactions. Important for the synthesis of nitrogenous bases in DNA and RNA.
Def: Macrocytic, megaloblastic anemia; no
neurologic symptoms (as opposed to vitamin
B12 deficiency)
Caused by: phenytoin, sulfonamides, MTX
-
Nutrition
Vitamin B12
- Cobalamin , cofactor for homocysteine methyltransferase and methylmalonyl-CoA mutase
-Def : Macrocytic, megaloblastic anemia,
hypersegmentecl PMNs, neurologic
symptoms (paresthesias, subacute combined
degeneration) clue to abnormal myelin.
- Found in animal products, def can be caused by malabsorption, lack of intrinsic factor, gasgric bypass, or lack of terminal ileum
- Schilling test is useful for etiology
Nutrition
S-Adenosyl-methionine
ATP + Methionine = SAM
Transfers methyl units
Regeneration of methionine/SAM dependent upon VitB9/B12
Required for converison of NE to Epi
Nutrition
Vitamin C
Ascorbic Acid
Antioxidant, facilitates Fe absorption by keeping it inFe2+ state
Necessary for prolinelysine hydroxylation in collagen synthesis
Necessary for dopamine-B-hydroxylase for dopamine–> NE
Def: Scurvy (swollen gums, bruising, hemarthrosis, anemia, healing), weakened immune response
Excess: N/V,diarrhea, fatigue, sleep
Nutrition
Vitamin D
D2 (plants), D3 (milk, sun-exposed skin) –> converted to calcidiol in liver and calcitriol (active form) in kidney
Fxn: increased intestinal Ca and Po absorption, increase bne mineralization
Def: Rickets, osteomalacia, hypocalcemia tetany
-breast milk has decreased vitD
Excess: hypercalcema,hypercalciuria, loss of appetite, stupor, seen in sarcoidosis via acivation of vitD by epithelial macrophages
Nutrition
Vitamin E
A-tocophenol
Fxn: antioxidant that protects RBC membranes from free radical damage
Def: increased fragility –> hemolytic anemia, muscle weakness, posterior columnspinocerebellar tract demyelination
