Скачать или смотреть Vitamin A 101: Understanding its Functions, Deficiency, and Toxicity

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Question: What are the components of Vitamin A?
Answer: Vitamin A includes retinal, retinol, and retinoic acid.Question: What is the function of Vitamin A?
Answer: Vitamin A functions as an antioxidant and is a constituent of visual pigments (retinal) and essential for normal differentiation of epithelial cells into specialized tissue (pancreatic cells, mucus-secreting cells). It also prevents squamous metaplasia.Question: What is the source of Vitamin A?
Answer: Vitamin A is found in liver and leafy vegetables.Question: What is the use of oral isotretinoin?
Answer: Oral isotretinoin is used to treat severe cystic acne.Question: What is the use of all-trans retinoic acid?
Answer: All-trans retinoic acid is used to treat acute promyelocytic leukemia.Question: What are the symptoms of Vitamin A deficiency?
Answer: Deficiency symptoms include night blindness (nyctalopia), dry, scaly skin (xerosis cutis), dry eyes (xerophthalmia), conjunctival squamous metaplasia leads to Bitot spots (keratin debris; foamy appearance on conjunctiva), corneal degeneration (keratomalacia), and immunosuppression.Question: What are the symptoms of Vitamin A excess?
Answer: Acute toxicity symptoms include nausea, vomiting, and increased ICP (eg, vertigo, blurred vision). Chronic toxicity symptoms include alopecia, dry skin (eg, scaliness), hepatic toxicity and enlargement, arthralgias, and idiopathic intracranial hypertension. Vitamin A is also teratogenic (cleft palate, cardiac abnormalities), therefore a negative pregnancy test and two forms of contraception are required before isotretinoin (vitamin A derivative) is prescribed. Question: How does Vitamin A supplementation affect measles patients?
Answer: Supplementation in vitamin A-deficient measles patients may improve outcomes.Question: What is the product 'Retin-A' used for?
Answer: Retin-A is a topical product used for wrinkles and acne.Question: What is the relationship between retinol and Vitamin A?
Answer: Retinol is Vitamin A.Question: What is xerophthalmia?
Answer: Xerophthalmia is a dry eye condition that is caused by Vitamin A deficiency.Question: What are Bitot spots?
Answer: Bitot spots are foamy appearances on the conjunctiva caused by keratin debris as a result of conjunctival squamous metaplasia which is caused by Vitamin A deficiency.Question: What is keratomalacia?
Answer: Keratomalacia is a condition in which the cornea degenerates due to Vitamin A deficiency.Question: What is the effect of Vitamin A deficiency on the immune system?
Answer: Vitamin A deficiency causes immunosuppression.Question: What are the symptoms of acute Vitamin A toxicity?
Answer: Symptoms of acute toxicity include nausea, vomiting and increased ICP (e.g., vertigo, blurred vision).Question: What are the symptoms of chronic Vitamin A toxicity?
Answer: Symptoms of chronic toxicity include alopecia, dry skin (e.g., scaliness), hepatic toxicity and enlargement, arthralgias, and idiopathic intracranial hypertension.Question: What is the effect of Isotretinoin on pregnancy?
Answer: Isotretinoin is teratogenic, it causes cleft palate and cardiac abnormalities therefore a negative pregnancy test and two forms of contraception are required before isotretinoin is prescribed. Question: What is the recommended daily intake of Vitamin A for adults?
Answer: The recommended daily intake of Vitamin A for adults is 900-3000 micrograms per day, depending on the individual's age, sex, and other factors.Question: What are the food sources of Vitamin A?
Answer: Vitamin A is found in many food sources such as liver, leafy greens, sweet potatoes, carrots, milk, cheese, and butter. Some fruits such as apricots, cantaloupe, and watermelon also contain Vitamin A.Question: What are the possible side effects of Vitamin A supplements?
Answer: Possible side effects of Vitamin A supplements include nausea, vomiting, and headaches. High doses of Vitamin A supplements can lead to toxicity symptoms such as hair loss, dry skin, and liver damatab