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PROMOTES Growth Immune System Health Mucus Membranes Health Antibody Response White Blood Cell Function Secretion of the Gastric Juices Repair of Intestinal Cells Good Eyesight Strong Bones Healthy Teeth Healthy Skin Healthy Kidney and Bladder Healthy Red Blood Cells
PROTECTS AGAINST Nerve Deterioration Viral Infections Upper Respiratory Infections Indigestion Acne
Beneficial daily supplement dosing ranges between
Toxicity can occur:Adults- doses > 200mg or 660,000iu Children- doses > 100mg or 333,000iu
Pregnant woman who are HIV+ should not take vitamin A supplements and it is in question whether anyone with HIV disease should take this vitamin in supplement form. More studies are needed.
Overview Vitamin A belongs to a class of compounds called retinoids and is identified as all-trans retinol. This family includes the aldehydes retinal and retinoic acid. It is found in animal products.
Some carotenoids, particularly beta-carotene, alpha-carotene & gamma-carotene, are found exclusively in fruit and vegetable sources. They represent about 10% of the carotinoids and are another group in the vitamin A family. Two linked Vitamin A molecules in these carotenoids are split by enzymes in digestion when the body needs Vitamin A.
Vitamin A is stored in the liver and does not need to be in the diet on a daily basis. Vitamin A needs to be mixed with fats and minerals to be absorbed from the gastrointestinal tract.
Long term Vitamin A deficiency causes keratinization of the skin. Here the skin becomes dry and rough with small bumps overall because many of the hair follicles have a build up of keratin which is stiff protein.
A condition that causes hardening of the inside of he eyelids called xerophthalmia can develop from Vitamin A deficiency and is the cause of blindness in many infants and children in the developing world. These children often also have growth and development retarded for many reasons, but the Vitamin A deficiency hinders bone and dental development and causes deformities.
Some cholesterol reducing medications and antibiotics deplete vitamin A. Mineral oil can deplete it as well.
See DRUG DEPLETION TABLE for specific drug information.
Food preparation to retain Vitamin A: - eat raw fruits & vegetables (or steam) to retain Beta Carotene a precursor of vitamin A - bake, braise, broil or roast meats - some vitamin A is lost in fat during frying
-Butter -Egg yolks -Meats (especially liver) -Milk (whole) -Fish & Fish Oil -Chicken
Low fat and skim milk lose Vitamin A with fat removal and are often fortified.
Vitamin A is necessary for vision, the growth and maintenance of epithelial tissue which is found predominantly as the inner-most layer of blood vessels, and the growth and development of bones and teeth. It also regulates immunity and reproduction. It is theorized to have some anti-cancer activity.
----------------------------------------------------- Excessive consumption of vitamin A can cause birth defects.
It has been identified as a developmental toxin when taken during pregnancy at doses higher than 10,000 iu/d.
Because vitamin A is required to ensure reproductive health, it has been recommended that pregnant women maintain their intake around 5,000 iu/d and taken in the beta-carotene form which is not toxic if taking a supplement.
There is an 80-90% absorption rate for vitamin A supplements, while 5 to 50% of beta-carotene is absorbed.
------------ A synthetic vitamin A drug called accutane caused hydrocephaly, microcephaly (small head), mental retardation, ear & eye abnormalities, cleft lip and palate, other facial deformities and heart defects according to a report by the March of Dimes in 1999. Also pregnant women should limit the amount of liver they eat according to a CDC report in 1995.
---------------------------- HIV+ Pregnant Women: A recently reported study of vitamin supplementation of HIV+ women in Tanzania showed increased transmission of HIV from mother to baby with vitamin A supplementation when the woman was pregnant. HIV+ pregnant woman SHOULD NOT TAKE VITAMIN A SUPPLEMENTS.
---------------------------------- Vitamin A supplements & HIV: In the Tanzania study the beneficial effects of the antioxidant vitamins used, including C & E, was diminished by combining with Vitamin A. Complications of the oral and gastrointestinal tract where enhanced with its use. This brings into question whether vitamin A supplementation should be taken by HIV+ individuals at all.
---------------------------- Vitamin A Treats Warts: Warts can be very stubborn and frequently return when liquid nitrogen cryotherapy treatment has seemed successful. In individuals without liver compromise, taking Vitamin A at 30,000 iu 3x a day for one week then off a week -- repeating in this sequence until gone or a maximum of three cycles may bring better success. There are many texts that recommend 20,000 to 30,000 iu daily for a three month period, but this may be excessive.
A 2002 study found that occlusive duct tape was better than cryotherapy for resolution of common warts. (Dean, Spicer, Fairchok, Arch Ped Adol Med, 2002; 156:971-974)
I have had good success using a combination of the Vitamin A regimen and the occlusive duct tape over the wart of patients with stubborn planter warts, but make sure women of child bearing age are not pregnant prior to and during use.
Recommended Dietary Allowance: The RDA -recommended dietary allowance- for Vitamin A is 5000 international units per day (iu/d).
RDA/AI* (Adequate Intake)
AGE (YRS) AMOUNT in micrograms (mcg) /day
Infants 0.0-0.5: 400 - 500* 0.5-1.0: 400 - 500*
Children 1-3: 300 - 400 4-8: 300 - 400
Males 9-13: 600 14-18: 900 19-30: 900 31-50: 900 51-70: 900 71+: 900
Females 9-13: 600 14-18: 700 19-30: 700 31-50; 700 51-70: 700 71+: 700
Pregnant >18yo: 770
Lactating >18yo: 1300
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