Questions and Answers
What condition refers to the dryness of the cornea in vitamin A deficiency?
Which of the following is considered a nonspecific skin change in vitamin A deficiency?
What laboratory investigation is NOT typically used to assess vitamin A deficiency?
Which of the following features is NOT associated with vitamin A deficiency?
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What is the normal range for serum retinol levels in the context of vitamin A deficiency?
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What condition is characterized by high cardiac output failure due to thiamine deficiency?
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Which food item is particularly harmful due to its high level of thiaminase?
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What is an early symptom of dry beriberi?
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What biochemical test is used to assess thiamine levels?
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Which condition is predominantly characterized by peripheral neuropathy and can occur due to thiamine deficiency?
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Which of the following is NOT a consequence of thiamine deficiency?
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What condition may develop in infants who are breastfed by thiamine-deficient mothers?
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Which of the following factors is associated with increased thiamine depletion?
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What is a common symptom of hyperemesis gravidarum related to thiamine depletion?
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Which symptom is commonly associated with Wernicke's encephalopathy?
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What is a key clinical feature of Wernicke's encephalopathy?
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What is the initial treatment approach for a patient with Wernicke's encephalopathy?
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What is the characteristic gait disturbance in Wernicke's encephalopathy caused by?
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What is a common memory disturbance associated with Korsakoff's psychosis?
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Which feature describes confabulation in Korsakoff's syndrome?
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What is the typical dosage regimen for administering thiamine in cases of Wernicke's encephalopathy?
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What condition may be precipitated by administering intravenous glucose solutions to individuals with thiamine deficiency?
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Which of the following is not a characteristic of Wernicke's encephalopathy?
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Which vitamin deficiency is primarily associated with Korsakoff's psychosis?
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What is the primary role of vitamin A in maintaining vision?
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Which of the following conditions is NOT associated with vitamin A deficiency?
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Which source contains preformed vitamin A?
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What process regulates the absorption of provitamin A from plant sources?
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Which vitamin A derivative is used for treating acute promyelocytic leukemia?
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Which of the following is a symptom of vitamin A deficiency?
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In which body organ is the majority of retinol stored?
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What is one function of retinoids in the body?
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What type of cells are replaced by keratin-producing cells due to vitamin A deficiency?
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What is the effect of excessive intake of preformed vitamin A?
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Study Notes
Thiamine Deficiency
- Beriberi Management: Includes complete bed rest and thiamine supplementation (200 mg thrice daily until acute symptoms resolve, then 10 mg/day).
- Wet Beriberi: Characterized by cardiovascular symptoms such as tachycardia, wide pulse pressure, and congestive heart failure. Can lead to sudden heart failure in infants from thiamine-deficient breastfeeding mothers.
- Dry Beriberi: Presents with symmetrical peripheral neuropathy, stiffness, weakness, and loss of reflexes, primarily affecting the legs.
- Wernicke's Encephalopathy: Defined by a triad of confusion, ophthalmoplegia, and ataxia; reversible with thiamine treatment. Associated with serious cognitive impairments if untreated.
- Diagnosis of Wernicke's: Thiamine levels and transketolase activity measured in fresh heparinized blood; MRI can show characteristic brain lesions.
- Korsakoff's Psychosis: Memory disturbance characterized by intact long-term memory and the phenomenon of confabulation, often seen in chronic alcoholics with thiamine deficiency.
- Responses to Treatment: Rapid response to thiamine supplementation indicates diagnosis of deficiency.
Causes of Thiamine Deficiency
- Lack of Intake: Starvation, consumption of thiaminase-rich foods (e.g., raw fish), and anti-thiamine factors found in tea and coffee.
- Increased Requirements: High carbohydrate diets, pregnancy, hyperthyroidism, severe infections, and physical exertion.
- Decreased Absorption: Conditions like chronic intestinal disease, alcoholism, and post-surgical states like gastric bypass.
- Increased Loss: Diarrhea and renal dialysis can deplete thiamine levels.
Vitamin A Deficiency
- Corneal Xerosis and Keratomalacia: Symptoms of advanced deficiency include dry, hazy cornea which can lead to destruction.
- Night Blindness: Impairment in vision due to retinal dysfunction, common symptom of vitamin A deficiency.
- Skin Changes: Nonspecific symptoms like xerosis, hyperkeratosis, and phrynoderma, indicating systematic effects.
- Immunological Impact: Deficiency leads to increased infection susceptibility due to impaired humoral and cell-mediated immunity.
- Other Symptoms: Include fatigue, anemia, diarrhea, decreased growth, bone development, and infertility.
- Laboratory Tests: Serum retinol levels (normal range 28-86 µg/dL) and albumin levels indicate vitamin A status; CBC may be necessary if anemia is suspected.
- Provitamin vs. Preformed Vitamin A: Provitamin A (carotenoids) is plant-derived and requires conversion; preformed vitamin A (retinol) comes from animal sources and is directly absorbed.
- Vitamin A Functions: Essential for vision, immune response, cell growth regulation, and lipid metabolism.
- Therapeutic Uses of Retinoids: Include treatments for conditions like acne and leukemia with derivatives like tretinoin and isotretinoin.
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Description
Explore the various causes of thiamine deficiency in this quiz. From dietary habits to physiological states, understand how lack of thiamine intake and increased consumption can impact health. Test your knowledge on the factors that contribute to this nutritional challenge.
