Natural vitamin A in a sesame oil base.
Vitamin A is essential supplement for all mammals. Preformed vitamin A is a group of fat-soluble compounds of animal origin called retinoid. It is found in eggs, milk products and animal liver. In countries low in foods derived from animals, carotenoids from vegetables need to supply the requirements for Vitamin A. In Asia and Africa this can be 80% of the dietary intake and in the Western diet as much as 40% of dietary intake.
- Contributes to the maintenance of normal vision
- Contributes to the maintenance of normal skin.
- Vitamin A has a role in the process of cell specialisation.
- Contributes to the normal development and function of the immune system
- Contributes to normal iron metabolism
- Contributes to the maintenance of normal mucus membranes
Alpha and beta-carotene can be converted to Vitamin A by an enzyme in the small intestine. Dietary preformed Vitamin A is absorbed in the upper part of the small intestine in a similar manner to fat absorption. Short chain retinal esters are hydrolysed by pancreatic lipase and long chain retinal esters by an enzyme in the cells of the small intestine. The released vitamin A (Retinol) is absorbed into the small intestine cells where it becomes bound to a protein (Retinol binding protein 2 ). This intracellular retinol is re-esterified and packaged into chylomicrons in the lymphatic system and then released into the general circulation. The chylomicrons are then hydrolysed by lipoprotein lipase and taken up by the tissues, usually by specific receptors, particularly in the liver, where it is stored.
Intracellular retinol is converted to retinal and then to retinoic acid and catalysed by alcohol dehydrogenase enzymes. These enzymes act as regulators of tissue retinoic acid levels.
Without proper instruction Vitamin A can be toxic so please consult your health practitioner before taking this supplement.