Vitamin A (Retinol,
Betacarotene)
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Category:
Description:
Indications:
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Vitamin
A deficiency
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Conditions
associated with vitamin A deficiency include: biliary tract or
pancreatic disease, sprue, colitis, hepatic cirrhosis, celiac disease,
regional enteritis, cystic fibrosis, partial gastrectomy or severe
dietary inadequacy
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Vision,
night blindness
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Tooth
and bone development
Contraindications:
Precautions:
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Pregnancy
category C
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Patients
may develop hypervitaminosis A with excessive dosages
Symptoms of hypervitaminosis A are cirrhotic-like liver
syndrome, malaise, irritability, headache, lip fissures, dry and
cracking skin, alopecia, and arthralgia.
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Do
not administer over 25,000 IU per day.
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Long
term use of large systemic doses of vitamin A to treat acne have not
been established. However
topical vitamin A derivatives (tretinoin and isotretinoin) are
available.
-
Oral
contraceptives significantly increase plasma vitamin A levels.
Adverse
Reactions (Side Effects):
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Dosage:
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Vitamin
A activity is expressed in Retinol Equivalents (RE)
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1
RE = 1mcg retinol or 6mcg beta-carotene = 3.33 IU (international
units)
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Dietary
sources: Yellow-orange vegetables (carrots), dark leafy vegetables
(spinach), fatty foods (liver, fish, dairy products)
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Administered
orally (soft gelatin capsules, tablets, drops) and injection
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Dietary
supplementation (RDA: recommended daily allowance):
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Males:
3300 IU per day
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Females:
2640 IU per day
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Treatment
of deficiency:
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Adults
and Children (>8 years):
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severe
deficiency with xerophthalmia: 5000,000 IU/day for 3 days,t hen
50,000 IU/day for 2 weeks
-
severe
deficiency: 100,000 IU/day for 3 days, then 50,000 IU/day for 2
months
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Follow-up:
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Adults:
10,000-20,000 IU/day for 2 months
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Children
(1-8 years): 5000-10,000 IU/day for 2 months
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Parenteral
(IM):
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Adults:
100,000 IU/day for 3 days, then 50,000 IU/day fir 2 weeks
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Children
(1-8 years): 17,500-35,000 IU/day for 10 days
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Infants:
7500-15,000 IU/day for 10 days
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Source:
Operational Medicine 2001, Health
Care in Military Settings, NAVMED P-5139, May 1, 2001, Bureau
of Medicine and Surgery, Department of the Navy, 2300 E Street NW, Washington,
D.C., 20372-5300
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