Vitamin A

Interesting facts about Vitamin A:

Vitamin A is a fat-soluble vitamin
Since vitamin A is a fat-soluble vitamin, it requires some fat to be eaten at the same time, to enable it to be digested and absorbed properly so that it can be used by the body as required.
Vitamin A is a potent antioxidant
Vitamin A's antioxidant properties are very potent - it acts to scavenge free radicals in the body that may otherwise do damage to DNA and raise risk of cancer and heart disease. Vitamin A reduces the oxidative damage that may otherwise occur in the cells of the body, from free radicals causing damage to them, if it was not available to neutralise and remove them.

Vitamin A is only found in animal and animal product food sources

Vitamin A exists in the epithelial and mucous tissues, as well as the retina
Vitamin A is found in the mucous (respiratory, gastrointestinal) and epithelial (urinary) cells of the body. The vitamin A in these cells helps to keep these cells moist and flexible, so that when any foreign substance (pathogen such as virus or bacteria) enters, these cells and tissues are able to eject the pathogen easily and resist infection. Without vitamin A, these cells may become stiff and dry, thus not providing the correct defense and allowing in the pathogen and enabling infection.
Vitamin A is only found in animal food sources
Vitamin A is only found in animal and animal product food sources. Vitamin A in animal foods (and animal products such as eggs, milk, cheese) comes pre-formed, so that the body does not have to process it in order to be able to absorb it - the vitamin A simply goes to the intestines where it is absorbed and used as required (including some storage in the liver).

References

Ambalavanan N, Tyson JE, Kennedy KA, et al. Vitamin A supplementation for extremely low birth weight infants: outcome at 18 to 22 months. Pediatrics 2005;115(3):e249-e254
Barker ME, Blumsohn A. Is vitamin A consumption a risk factor for osteoporotic fracture?. Proc Nutr Soc. 2003;62:845-850
Cox SE, Arthur P, Kirkwood BR, et al. Vitamin A supplementation increases ratios of proinflammatory to anti-inflammatory cytokine responses in pregnancy and lactation. Clin Exp Immunol. 2006 Jun;144(3):392-400
Fletcher AE, Breeze E, Shetty PS. Antioxidant vitamins and mortality in older persons: findings from the nutrition add-on study to the Medical Research Council Trial of Assessment and Management of Older People in the Community. AJCN, 2003; Vol 78(5): 999-1010
Griffith HW. Minerals, Supplements and Vitamins - The Essential Guide. 2000 Fisher Books, USA
Lieberman S, Bruning N. The Real Vitamin and Mineral Book - Using Supplements for Optimal Health. 3rd Edition. Avery Publishing, New York, 2003
Osiecki, Henry, The Nutrient Bible 2002, BioConcepts Publishing

24 June 2013