Vitamin A food sources
5. Immunity problems:
Repeat infections such as sinusitis,
ear infections, candidiasis, fungal infections, and particularly,
respiratory infections.
Poor recovery from infections such as flu
and colds or sores.
6. Reproductive problems:
Impairment of sperm formation in males.
Spontaneous abortion in
females.
Impaired development of embryo
7. Failure to
grow, or growth retardation, is the most common sign in children.
Food Sources of Vitamin A
Excellent: Liver, chicken giblets, oysters, cod, halibut.
Good:
Milk, cheese, butter, eggs and other fish.
Very good: Carrot juice, sweet potato with peel, pumpkin, carrots.
Good: Dark green leafy vegetables such as spinach, collards, kale,
beet greens, turnip greens.
Recommended Daily Dietary Allowances for Vitamin A:
Children 1 to 3 years: 600 micrograms (2,000 IU))
Males add females 19 years and older: 3,000 mcg (10,000 IU)
Drugs that increase blood levels of vitamin A include Lescol, Mevacor, Provachol and Zocor, while those that interfere with vitamin A absorption include Cholestyramine and Colestid.
Contraceptives may increase blood levels of vitamin A. Neomycin, an antibiotic, may decrease the absorption of vitamin A.
Impact of Storage, Processing, and Cooking
Vitamin A is unaffected by light, heat and usual cooking methods. It is destroyed by oxidation (exposure to air), drying, very high temperatures and ultraviolet light. Keep food wrapped to protect it from air and sunlight.
Nutrient Interactions
Excessive vitamin A may interfere with vitamin K absorption.
Toxicity
Persistent high doses of vitamin A (not carotenoids) of over 14,000 IU in infants or 33,000 IU in adults overcomes the liver's ability to store it and can produce toxicity. Children and people with kidney failure are at high risk of toxicity and should always inform their physician of any supplement use. Excessive alcohol consumption increases toxicity. Toxic effects of vitamin A (in the form of retinoic acid) exceeding 10,000 IU when used as a supplement by pregnant women or as the active ingredient in acne products like Accutane have been shown to cause malformations such as spina bifida in their developing fetuses.
Symptoms of vitamin A toxicity include dry lips is an early sign, followed by dryness of the nasal tissues. Later signs include dryness, redness, scaling, and peeling of skin, hair loss and nail fragility. Other symptoms can include vomiting in infants and children, headache, nausea, bone pain, fractures, fatigue and muscle pain.
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