Vitamin A has had a bad reputation for a while and many people think that they have to be away from it. The most danger from vitamin A is if you eat the liver of a bear or liver everyday, which can contain a lot of the vitamin A and other nutrients. The following are facts about vitamin A:
Vitamin A is one vitamin that has a bed reputation for being bad in pregnancy. But a vast majority of pregnant women and children in the third country and some in the western world are deficient of this vitamin. This leads to many problems in the foetus and pregnancy as well as reducing the activity and function of the immune system.
Vitamin A has an important role in the mucosal surfaces of the intestinal tract (which is the first line of defence for the body) and the lining of the lungs. Deficiency of the vitamin A leads to night-blindness, xerophtalmia, retardation of growth, impaired reproductive capacity and anaemia.
There are two ways that you can get the vitamin A, directly from food via animal sources in the retinol form. These foods are egg yolk, liver, butter, cheese, whole milk and cod-liver oil. The pro-vitamin A in the form of beta-carotene is found in vegetables foods such as dark green leafy vegetables, yellow and orange foods such as carrots, sweet potatoes, mangoes, papaya, oranges and tangerines and many others..
Vitamin A receptors is very closely involved in the gene expression (DNA expression, where each individual body takes their instruction) and therefore involved in regulating genes.
Vitamin A is essential for the mucosal surfaces of the gastrointestinal, respiratory and genitourinary tracts and it is also essential for the lymphoid system of the mucosal tract Deficiency of vitamin A in childhood is one of the most causes of mortality in the developing world.
Deficiency in vitamin A can lead to:
• Abnormal expression of keratins in the respiratory tract, genitourinary tract and ocular surface
• Loss of Cilia from respiratory epithelium
• Loss of microvilli from small intestine
• Impaired neutrophil function + other immune system cells.
• Impaired natural killer (NK) cell function and decreased number of NK cells (NK are included in the immunity as anti-viral and anti-tumour immunity)
Some studies have shown that children with deficiency of vitamin A are more at risk of mortality from measles. Children given vitamin A, showed reduce mortality and less complication from measles. Children who received 60mg of retinoic acid had significantly higher IgG responses to measles virus and higher circulating lymphocytes counts during follow up compared with children receiveing placebo.
Diarrhoeal disease caused by rotavirus, Escherichia coli, Shigella, Vibrio cholerae Salmonella and Entamoeba histolytica have been shown to reduce mortality and morbidity from these pathogens by fortification or supplementation of the vitamin A in Tamil Nadu, Nepal, Ghana and Brazil.
Vitamin A in pregnancy and lactation might has shown to be very important for the immune system and for night blindness. Vitamin A in the form of beta-carotene has shown to reduce all cause of mortality and morbidity in the developing countries and western world. Beta-carotene needs zinc to be converted into the retinoic acid.
Mucosal immunity – intestinal tract immunity and repair of the gastrointestinal tract together with vitamin D, zinc and glutamine.
Well the above was a bit scientific but it is nice sometime to have some breakdown of what the actual nutrient do in your body and how wonderful our body is to make all these things from just a little nutrient and which we get from our healthy food!!!!!