Significant Facts of Vitamins
•√ Night blindness (Nyctalopia) is decreased ability to see at night, caused by lack of visual purple in the rods or to its slowness in regenerating after exposure to light, May result from vitamin A deficiency
•√ A1 is a form of vitamin A found in cod liver oils and A2 is a compound found in the liver of fresh water fishes, similar in properties to A1 but different in ultraviolet absorption spectra.
•√ Vitamin A is formed in the body from precursors, yellow pigments of plants (alpha, beta and gamma carotene). It is essential for normal growth and development, the integrity of epithelial issues and for normal tooth and bone development. It is stored in liver.
•√ Vitamin B-complex is a group of water-soluble vitamins isolated from liver, yeast and other sources. Among this, vitamins included are B1 (aneurine or thiamine), B6 (pyridoxine), niacin (nicotinic acid), biotin, folic acid, pantothenic acid, B12 (cyanocobalamin)
•√ Vitamin C (Ascorbic acid) is a factor necessary for formation of intercellular substance of connective tissue and essential in maintenance of integrity of intercellular cement in many tissues, especially capillary walls. Deficiency leads to scurvy, imperfect prenatal skeleton formation, pyorrhoea.
•√ Excess doses of vitamin C for an extended period can interfere with absorption of vitamin B12, cause urico-suria and promote formation of oxalate kidney stones.
•√ Vitamin D is one of several vitamins having antirachitic activity.
•√ Vitamin D group includes D2 (calciferol), D3 (irradiated 7-dehydrocholesterol), D4 (irradiated 22-dehydro-ergosterol) and D5 (irradiated dehydrositosterol).
•√ In humans 7-dehydrocholesterol is secreted in the skin, where it is activated by sunlight and vitamin D3 is formed and reabsorbed
•√ Vitamin D2 is formed by the ultraviolet irradiation of ergosterol, a vitamin D precursor found in plants.
•√ The main circulating form of vitamin D in humans is 25-dehydroxycholecalciferol and is very active, derived by modification of cholecalciferol in the liver. It promotes uptake of calcium ions from the ileum and is required for calcification of bones and teeth.
•√ Vitamin D deficiency in infants causes rickets and in adults osteomalacia.
•√ Excess doses of vitamin D for a prolonged period will cause hypercalcemia with anorexia, polydipsia and altered renal function.
•√ Vitamin E (tocopherol) seems to prevent oxidation of highly unsaturated fatty acids (and their polymerization in cell membranes) in presence of molecular oxygen.
•√ Vitamin E are widespread in nature and are particularly concentrated in vegetable oils.
•√ Vitamin E deficiency has often been associated with reproductive failure and irreversible testicular damage.
•√ Vitamin K is naturally occurring vitamin consisting of two chemically similar yellowish oils known as K1 and K2, which are fate soluble nonsteroid, non-saponifiable and unstable to light
•√ Vitamin K (K1 and K is required for synthesis in liver of proconvertin, which is required for prothrombin production and so for conversion of fibrinogen to fibrin during blood clotting.
•√ Vitamin K1 is produced by many plants, while K2 by microorganisms including those in the human gut.
Some Avitaminosis, Deficiency Causing Vitamins
•√ Antiberiberi == Thiamine (vitamin B1)
•√ Antidermatisis == Pyridoxine (vitamin B6)
•√ Antipellagra == Niacin (Nicotinamide or nicotinic acid)
•√ Antihaemorrhagic == Vitamin K
•√ Antiinfective == Vitamin A
•√ Antirachitic == Vitamin D group
•√ Antiscorbutic == Ascorbic acid (vitamin C)
•√ Antixerophthalmic == Vitamin A
•√ Coagulation == Vitamin K
