|
Vitamin A is fat-soluble vitamin that is in the same family of compounds as retinol, retinal and beta-carotene. Beta-carotene is also known as pro-vitamin A because it can be converted into vitamin A when additional levels are required. Vitamin A and beta carotene are essential for healthy eyes (night blindness, cataracts, conjunctivitis, retinopathy and macular degeneration), a properly functioning immune system, bone health as well as healthy hair, skin and nails. It is also used to treat acne or other skin ailments; prevent infection, as an anti-aging vitamin, and an anti-cancer vitamin. It may also help to prevent or treat such conditions as Crohn’s disease, diarrhea, and heavy menstruation, peptic ulcer, and premenstrual syndrome.
Dietary Sources: Food sources include organ meats such as liver and kidney, egg yolks, butter, fortified dairy products such as milk and some margarines and cod liver oil.
Dosage: The RDA for vitamin A is 5,000 IU for adults. Children should consume no more than 3,500IU daily. Although there is no established DV for beta carotene, a daily intake of 5-20 mg has been advocated by some nutrition experts. A prudent recommendation for vitamin A intake may be no more than 10,000 IU/day with at least half of that being supplied by beta-carotene.
Side Effects: As a fat-soluble vitamin, vitamin A can be stored in the body and levels can build up over time. Possible toxicity can result with high dose supplementation (50,000 IU/day) leading to vomiting, headaches, joint pain, skin irritation, gastrointestinal distress and hair loss.
There seems to be feverish work on vitamin A in the USA possibly because in it’s synthetic form it can be patented and is being used for a variety of conditions, notably acne and cancer chemotherapy. These forms of vitamin A are also notably toxic.
(Source: www.supplementwatch.com)
Research Overview
Vitamin A research shows the following:
Deficiency in Vitamin A leads to:
1. Congenital birth defects
2. Kidney disease
3. Pregnancy anemia
4. Eye abnormalities in newborns
5. Deformed palates in newborns
6. Kidney infection
7. Kidney stones
Supplementation of Vitamin A:
1. May reduce risk of osteoarthritis
2. May reduce risk of osteoporosis
3. Decrease risk of breast cancer
4. Those with HIV and tuberculosis have vitamin A deficiency
5. Those with rheumatoid arthritis have low levels of vitamin A
6. Those with type II diabetes have low levels of vitamin A
7. Those with macular degeneration have low levels of vitamin A
8. Those with spinal cord injuries have low levels of vitamin A
9. Those with coronary artery disease have low levels of vitamin A
10. Prevents lipid peroxidation from iron overload
11. Is a powerful antioxidant
12. Premature babies with low birth weight have low vitamin A levels
13. Supplementing newborns with vitamin A can reduce infant mortality
14. Cigarette smoking depletes vitamin A and increases risk of emphysema
15. Normalizes homocysteine levels
16. Improves sinus wound healing
17. Reduces tumor growth and metastasis
18. Decreases risk of prostate cancer
19. Is treatment for vascular disease
20. Prevents night blindness
21. Prevents bronchopulmonary dysplasia and death in newborns
22. Improves wound healing in general
23. May be used in treatment of lupus
24. Reverses precancerous conditions
25. Reduces risk of chronic liver disease
26. Reduces risk of liver cancer
27. May help prevent measles
28. Reduces risk of cataract development
29. Is a treatment for H pylori bacteria
Vitamin A Abstract Summaries (249) |