Vitamin A Supplements
During the absorption process in the intestines, retinol is incorporated into chylomicrons as the ester form, and it is these particles that mediate transport to the liver. Liver cells (hepatocytes) store vitamin A as the ester, and when retinol is needed in other tissues, it is de-esterifed and released into the blood as the alcohol. Retinol then attaches to a serum carrier, retinol binding protein, for transport to target tissues. A binding protein inside cells, cellular retinoic acid binding protein, serves to store and move retinoic acid intracellularly.
All forms of vitamin A are used in cosmetic and medical applications applied to the skin.
Retinoic acid, retinyl palmitate, isotretinoin, tretinoin and retinol are all used medicinally as a topical treatment for acne and keratosis pilaris.
In cosmetics, vitamin A derivatives are used as so-called antiaging chemicals- vitamin A is absorbed through the skin and increases the rate of skin turnover, and gives a temporary increase in collagen giving a more youthful appearance.
Prevalence of vitamin A deficiency. Source: WHOVitamin A deficiency is common in developing countries but rarely seen in developed countries. Approximately 250,000 to 500,000 malnourished children in the developing world go blind each year from a deficiency of vitamin A. Night blindness is one of the first signs of vitamin A deficiency. Vitamin A deficiency contributes to blindness by making the cornea very dry and damaging the retina and cornea.
Vitamin A deficiency diminishes the ability to fight infections. In countries where children aren't immunized, infectious disease like measles have relatively higher fatality rates. Subclinical deficiency can also be a problem as it may increase children's risk of developing respiratory and diarrheal infections, decrease growth rate, slow bone development, and decrease likelihood of survival from serious illness. Iron deficiency can also affect vitamin A uptake.
Excess alcohol consumption can deplete vitamin A, however a stressed liver may be more susceptible to vitamin A toxicity. People that consume large amounts of alcohol should seek medical advice before taking vitamin A supplements.
Promile offer a wide variety of the latest and safest vitamin A mineral supplement tablets available.