Vitamin A plays an important role in the protection of the epithelial tissues (including retina and skin) and the mucous membranes and therefore as a protection against general infections.
- Vitamin A plays an important role in the protection of the epithelial tissues (including retina and skin) and the mucous membranes and therefore as a protection against general infections.
- Vitamin D3 takes care of the regular process of the calcium-phosphorous metabolism. It also plays a role in increasing the rate of Ca++- absorption and transport from the intestine and so promoting calcification of bone.
- Vitamin E has an anti-oxidant action.
- This action links vitamin E with vitamin A metabolism (it is used for the stabilizing of vitamin A in foodstuffs), and with the unsaturated fatty acids.
- Vitamin AD3E Oral is indicated for treatment and prevention of deficiencies of the vitamins A, D3 and/or E, in connection with general bacterial infections, improvement of rearing results, growth disturbances, non-infectious reproductive and sight disturbances, enteritis, convalescence and skin problems.
- Prophylactic treatment during strong labour and stressful situations.
- Vitamin A is necessary for support of growth, health and life of major animal species.
- In the absence of vitamin A, animals will cease to grow and eventually die.
- As a fat-soluble vitamin, vitamin A can be efficiently stored in the liver and yolk of birds, and it plays a role in both the biology of the adult bird and embryo development
Functions of vitamin A:
- Formation and maintenance of teeth, bones, soft tissue, white blood cells, the immune system and mucus membranes.
- Retinol not only creates the pigments in the retina of the eye, according to, but also is integral for good vision, especially night vision, and overall eye health.
- Vitamin A also promotes antibody responses to T-cell–dependent antigens and increases protective antitumor immunity through mechanisms such as induction of cell differentiation and enhancement of migration to lymph nodes.
- Beta-carotene also acts as an antioxidant, protecting cells from free radical damage.
- Vitamin A also helps feather grow .
- Improves egg production and hatchability.
- The primary function of vitamin D is to elevate plasma
- calcium and phosphorus to a level that will support normal
- mineralization of bone as well as other body functions.
1. Intestinal effects :
- It is well known that vitamin D stimulates active transport of calcium and phosphorus across intestinal epithelium
- In the intestine, 1,25-(OH)2D promotes synthesis of calbindin (calcium-binding protein) and other proteins and stimulates calcium and phosphorus absorption.
- Calbindin is not present in the intestine of rachitic chicks but appears following vitamin D supplementation.
- Vitamin D has also been reported to influence magnesium (Mg) absorption
- improving renal reabsorption of calcium.
- The active metabolite, 1,25-(OH)2D, brings about mineralization of the bone matrix.
- During bone formation in young animals, minerals are deposited on the protein matrix.
- This is accompanied by an invasion of blood vessels that gives rise to trabecular bone.
- This process causes bones to elongate.
- During a vitamin D deficiency, this organic matrix fails to mineralize, causing rickets in the young and Osteomalacia in adults.
4.Functions beyond bone mineralization:
- Vitamin D has also been shown to be required for embryonic development of the chick.
- Vitamin D treatment stimulated yolk calcium mobilization and the vitamin D-dependent Ca2+-binding protein, calbindin, is present in the yolk sac
- 1,25-(OH)2D is also essential for the transport of eggshell calcium to the embryo across the chorioallantois membrane.
- The actions of 1,25-(OH)2D involved in regulation of the growth and differentiation of a variety of cell types, including those of hematopoietic and immune systems.
- Vitamin E has been shown to be essential for
- integrity and optimum function of reproductive,
- muscular, circulatory, nervous and immune systems .
- It is well established that some functions of vitamin E, however, can be fulfilled in part or entirely by traces of selenium .
FUNCTIONS OF VITAMIN E:
1.Vitamin E as a Biological Antioxidant:
- the most important functions is its role as an intercellular and intracellular antioxidant.
- Therefore, antioxidants are very important to immune defense and health of humans and animals.
- Vitamin E is part of the body’s intracellular defense against the adverse effects of reactive oxygen and free radicals that initiate oxidation of unsaturated phospholipids.
- Vitamin E functions as a membrane-bound antioxidant, trapping lipid peroxyl free radicals produced from unsaturated fatty acids under conditions of “oxidative stress.”
Mechanism of action:
by neutralizing free radicals and preventing oxidation of lipids within membranes.
So, interrupt production of free radicals at the initial stage.
2.Membrane Structure and Prostaglandin Synthesis
- Alpha-tocopherol may be involved in the formation of structural components of biological membranes, thus exerting a unique influence on architecture of membrane phospholipids
- It is reported that alpha-tocopherol stimulated the incorporation of 14C from linoleic acid into arachidonic acid in fibroblast phospholipids.
- Also, it was found that alpha-tocopherol exerted a pronounced stimulatory influence on formation of prostaglandin E from arachidonic acid.
- vitamin E supplementation of diets increased intracellular kill of Staphylococcus aureus and Escherichia coli by neutrophils.
- vitamin E is an essential nutrient for the normal function of the immune system.
- vitamin E and selenium play role in protecting leukocytes and macrophages during phagocytosis, the mechanism whereby animals immunologically kill invading bacteria.
- Both vitamin E and selenium may help these cells survive the toxic products that are produced in order to effectively kill ingested bacteria.
- Macrophages and neutrophils from vitamin E-deficient animals have decreased phagocytic activity.
- The protective effects of vitamin E on animal health may be involved with its role in reduction of glucocorticoids, which are known to be immunosuppressive.
- Vitamin A deficiency symptoms are hyperkeratosis of the skin, xerophthalmia, blindness, nervous symptoms, decreased growth rates and lower fertility.
- Vitamin D3 deficiency symptoms are rickets in young animals and Osteomalacia in adults.
- vitamin E (deficiency symptoms are muscular disorders, e.g. White Muscle Disease, Stiff Lamb Disease).