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33 Cards in this Set
- Front
- Back
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Vitamin A functions
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-Retinol: derived from dietary beta-carotenes and retinol esters (main transport and storage form of Vitamin A
-Retinal - products of oxidation of retinol, component of rhodopsin -normal vision in reduced light Potentiating differentiation of mucus-secreting epithelium Stimulating immune system Growth and reproduction |
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Vitamin A sources
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liver, egg yolk, butter, milk
beta-carotenes in dark-green and yellow veggies |
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Causes of Vitamin A toxicity and symptoms
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-Caused by: consumption of bear liver, megadoses, treatment with isotretinoin
-Symptoms: Papilledema and seaizures (due to increased ICP), hepatitis, bone pain (due to periosteal proliferation) |
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Symptoms of Vitamin A deficiency
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Impaired night vision
blindness (due to squamous metaplasia of eye - white encroaches on cornea) follicular hyperkeratosis (loss of sebacous gland function) pneumonia growth retardation renal caliculi |
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Symptoms of Vitamin D deficiency
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pathologic fractures
excess osteoid bow legs kids: rickets, craniotabes (soft skull bones), rachitic rosary (defective mineralization and overgrowth of epiphyseal cartilage in ribs) adults - osteomalacia tetany |
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Symptoms of Vitamin D toxicity
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hypercalcemia with metastatic calcification
renal calculi |
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Symptoms of Vitamin E deficiency
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Hemolytic anemia (damage to RBC membrane)
peripheral neuropathy degeneration of posterior colum (poor joint sensation) degeneration of spinocerebellar tract (ataxia) |
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Symptoms of Vitamin E toxicity
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decreased synthesis of vitamin k-dependent procoagulant factors
synergistic effect with warfarin anticoagulation |
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Symptoms of Vitamin K deficiency
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newborns: hemorrhagic disease of newborn (must give at birth, breast milk deficient)
adults: GI bleeding, ecchymosis, prolonged PT and PTT |
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Symptoms of Vitamin K toxicity
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hemolytic anemia and jaundice in newborns if mother recieves excess vitamin K
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Functions of Vitamin D
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maintenance of serum calcium and phosphorus
required for mineralization of epiphyseal cartilage and osteoid matrix (receptor on osteoblasts stimulates release of ALP, which dephosphorylates pyrophosphate, which normally inhibits bone mineralization) stimulates macrophage stem cell conversion into osteoclasts Note: in liver, metabolized by CYP-450 |
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Functions of Vitamin E
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antioxidant - protects cell membranes from lipid peroxidation from free radicals, prevents oxidation of LDL to a free radical form)
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Functions of Vitamin K
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gamma-carboxylates glutamate residues in vitamin K-dependent procoagulants and anticoagulants (protein C and S) - factors 2 (prothrombin), 7,9,10
gamma carboxylation allows these procoagulants to bind calcium in fibrin clot formation |
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Sources of Vitamin K
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endogenous bacteria, dark green veggies
activated by liver microsomal enzyme epoxide reductase (anticoag effect of coumadin derives from the inhibition of epoxide reductase) |
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B1 deficiency
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-thiamine
dry beriberi, peripheral neuropathy due to demyelination, Wernicke-Korsakoff's syndrome, wet beriberi (congestive cardiomyopathy with biventricular failure) |
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B2 deficiency
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-Riboflavin
corneal neovascularization, glossitis, cheilosis, angular stomatitis |
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B3 deficiency
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-Niacin
pellagra (diarrhea, dermatitis - hyperpigmentation in sun-exposed areas, dementia) |
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B6 deficiency
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-pyridoxine
sideroblastic anemia, convulsions, peripheral neuropathy |
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B12 deficiency
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-cobalamin
megaloblastic anemia, neurologic disease (posterior column and lateral corticospinal tract demyelination), glossitis |
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Folic acid deficiency
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megaloblastic anemia, glossitis, no neurologic disease
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Biotin deficiency
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dermatitis, alopecia, lactic acidosis
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Vit C defciency
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Weak capillaries and venules
skin ecchymosis perifoliccular hemorrhage corkscrew hairs hemarthrosis bleeding gums anemia (combined with iron and folate deficiency) loosened teeth glossitis poor wound healing |
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Chromium deficiency
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impaired glucose tolerance, peripheral neuropathy
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Copper deficiency
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microcytic anemia (cofactor in ferroxidase)
aortic dissection (weak elastic tissue) poor wound healing (cofactor in lysyl oxidase) |
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Flouride deficiency
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dental caries
excess - chalky deposits on teeth, calcification of ligaments and increased risk of bone fractures |
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Iodide deficiency
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goiter, hypothyroidism
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Selenium deficiency
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muscle pain and weakness, dilated cardiomyopathy
in glutathione peroxidase |
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Zinc deficiency
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poor wound healing (cofactor in collagenase)
dysgeusia (cannot taste), anosmia, perioral rash kids: hypogonadism, growth retardation |
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Fat oxidation yield
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9 kcal/day
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Carb oxidation yield
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4 kcal/day
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Protein oxidation yield
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4 kcal/day
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Respiratory exchange rate (RER) post eating
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Rer - ratio of carbon dioxide production to oxygen consumption
-declines after a meal as fat replaces glucose as major fuel |
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When see tryptophan deficiency
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Hartnup disease
carcinoid syndrome - used up synthesizing serotonin |
