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pathopharm exam 4
CHAPTER 81
Question | Answer |
---|---|
Vitamins? | Organic compoundsRequired in minute amounts for growth and maintenance of healthAre not a source of energy |
VITAMINS ARE? | Essential for energy transformation and regulation of metabolic processesSeveral vitamins are inactive in native form and must be converted to active compounds in the body |
Intake of Vitamins? Recommended dietary allowances (RDAs) for vitamins are set by the Food and Nutrition Board of the National Academy of Sciences | RDAs represent the average daily dietary intake sufficient to meet the nutrient requirements of nearly all healthy individuals (97% to 98%) in a particular life stage or gender group |
Intake of Vitamins | he Tolerable Upper Intake Level (UL) for a vitamin is the highest average daily intake that can be consumed by nearly everyone without significant risk of adverse effects |
Intake of Vitamins | The UL is an index of safety; it is not a recommendation to exceed the RDA The estimated average requirement (EAR) is the level of intake that meets nutritional requirements for 50% of the healthy individuals in any life stage or gender group |
ntake of Vitamins? | The acceptable macronutrient distribution range (AMDR) is a range of macronutrients (eg, proteins, carbohydrates, fats) associated with optimal health. INTAKE BELOW AMDR=IncREAS. risk of malnourishment. INTAKE ABOVE=iNCREAS. risk of chronic diseases. |
Vitamins6 ARE? | Fat soluble •Vitamins A, D, E, K Water soluble •Vitamin C •Vitamin B complex: Thiamin, riboflavin, niacin, pyridoxine, pantothenic acid, biotin, folic acid, cyanocobalamin |
Vitamin A (Retinol) | Multiple functions in the eyes Toxicity Teratogenic, birth defects, hypervitaminosis liver injury, bone-related disorders Deficiency results in: Night blindnessXerophthalmia Keratomalacia Blindness |
Vitamins D and E may help protect against breast cancer, colorectal cancer, type 1 diabetes, and overall mortality. | Vitamin D Regulates calcium and phosphorus Deficiency causes rickets or osteomalacia Vitamin E Antioxidant properties Dietary sources: Fresh greens, seeds, oils Toxicity may increase risk for bleeding Increased risk of hemorrhagic stroke |
Vitamin K Action required for synthesis of prothrombin and other clotting factors-Deficiency produces bleeding | ADR=Hypersensitivity reaction,Hyperbilirubinemia in parenteral administration to newborns Correction or prevention of hypoprothrombinemia and bleeding caused by vitamin K deficiency Control of hemorrhage caused by warfarinVitamin K9 |
Water-Soluble Vitamins- | Vitamin C Members of the vitamin B complex: Thiamin, riboflavin, niacin, pyridoxine, pantothenic acid, biotin, folic acid, and cyanocobalaminWater |
Vitamin C | Action required for production of collagen and other compounds that bind cells together Part of the biochemical reaction for the synthesis of adrenal steroids |
Vitamin C | SourcesCitrus fruits/juices, tomatoes, potatoes, strawberries, melons, spinach, broccoliHas antioxidant propertiesFacilitates iron absorptionDeficiency can lead to scurvyVitamin C11 |
Vitamin B Complex | Niacin (nicotinic acid) Riboflavin (vitamin B2) Thiamin (vitamin B1) Pyridoxine (vitamin B6) Cyanocobalamin (vitamin B12) Folic acid |
Niacin (Nicotinic Acid) | Deficiency Pellagra: Dermatitis characterized by scaling and cracking of the skin in areas exposed to the sun GI disturbancesCentral nervous system (CNS)•Irritability, insomnia, memory loss, anxiety, dementiaNiacin |
ADVRSE EFFECTS Niacin (Nicotinic Acid) | Small doses devoid of adverse effects Large doses•Vasodilation with flushing, dizziness, nausea Therapeutic uses As a vitamin, used only as treatment for niacin deficiencyIf given in large doses, can decrease cholestero |
Riboflavin (Vitamin B2) | Involved in numerous enzymatic reactionsFirst, must be changed to flavin adenine dinucleotide (FAD) or flavin mononucleotide (FMN) ADRNone for humans, no UL Therapeutic usesRiboflavin deficiency Migraine headaches Riboflavin (Vitamin B2)15 |
Thiamine (Vitamin B1) | ActionsCoenzyme for carbohydrate metabolismRequirements increased slightly during pregnancy and breast-feedingDeficiencyBeriberiWernicke-Korsakoff syndrome |
Thiamine (Vitamin B1) | Wet beriberi Fluid accumulation in the legsCardiovascular complications (palpitations, electrocardiograph [ECG] abnormalities, high-output heart failure)May progress to circulatory collapse and deathRecovery is dramatic with replacement therapy |
Wet beriberi Cardiovascular complications (palpitations, electrocardiograph [ECG] abnormalities, high-output heart failure)May progress to circulatory collapse and deathRecovery is dramatic with replacement therapy | Dry beriberiNeurologic and motor deficits, no edema or cardiovascular symptomsRecovery is slow Fluid accumulation in the legs |
Thiamine (Vitamin B1) | Wernicke-Korsakoff syndrome (caused by alcoholism) Alcoholism is the most common cause of thiamin deficiency in the United States Serious CNS disorder (neurologic and psychologic)•Nystagmus, diplopia, ataxia, inability to remember recent past |
Pyridoxine (Vitamin B6 | Coenzyme in the metabolism of amino acids and proteinsMust first be converted to its active form, pyridoxal phosphate Sources Fortified breakfast cereals, meat, fish, poultry, white potatoes, other starchy vegetables, noncitrus fruits |
Pyridoxine (Vitamin B6) Dietary deficiency of vitamin B6 is rare in the United States except in alcoholics | DeficiencY May result from poor diet, isoniazid use, inborn errors of metabolism Symptoms Seborrheic dermatitis, microcytic anemia, peripheral neuritis, convulsions, depression, confusion |
Vitamin B Complex resless leg syndrome may not be absorbed PO COULD BE INJECTION OR SUBLINGUAL | Cyanocobalamin (vitamin B12) and folic acidBoth essential factors in the synthesis of DNA Deficiency of either manifests as megaloblastic anemia Cyanocobalamin deficiency also results in neurologic damage |
Folic Acid | Food folate versus synthetic folate Synthetic form is more stable U.S. Food and Drug Administration (FDA) ordered synthetic folate to be added to all enriched grain products |
Folic Acid | Deficiency of folic acid during pregnancy can impair CNS development Can result in neural tube defects, anencephaly, spina bifida Important for any patient who may become pregnant to take additional folic acid |
Pantothenic Acid | Essential component of two biologically important molecules: Coenzyme A and acyl carrier protein |
Biotin | Essential cofactor for several reactions involved in the metabolism of carbohydrates and fats |
A nurse is preparing a class on vitamin supplementation. What statement will be included in the class content? | Vitamin K is required to prevent bleeding. Vitamin K is required for the synthesis of prothrombin and other clotting factors. |
In which patient will the nurse suspect a thiamin deficiency? | A 42-year-old with alcoholism who has diplopia, ataxia, and memory loss with symptoms of neurologic and motor deficits. |
A deficiency of which vitamin is most likely to result in visual disturbances? | Vitamin A-night blindness, xerophthalmia (a dry, thickened condition of the conjunctiva), and keratomalacia (degeneration of the cornea with keratinization of the corneal epithelium). |
A patient who is in the early stages of Wernicke-Korsakoff syndrome has been admitted to the healthcare facility. Upon assessment of the patient, the nurse expects to find all but which manifestation? | Fixed, dilated pupils associated with severe neurologic damage or opiate drug overdose |