VITAMINS• “Vita” comes from the Latin word “Life”- “accessory growth factors”• Vitamins are mainly obtained from our foods, but there are some special cases.
FUNCTIONS OF VITAMINS• It is part of important processes throughout the body - help release energy from food - help keep skin and nerves healthy - help make red blood cells• They mainly serve as catalysts for certain reactions in the body.
GENERAL PROPERTIES Fat Soluble Vitamins Water Soluble VitaminsSoluble in fat and fat solvents Soluble in waterSmall amount excreted in the bile Excreted in the urineNot absolutely needed in the Must be supplied in the daily diet daily dietDeficiency symptoms are slowly Deficiency symptoms often to develop develop rapidlyHave precursors or provitamins. Generally do not have precursors
Fat Soluble Vitamins Water Soluble VitaminsContain the elements carbon, Contain theand hydrogen, and oxygen elements carbon, hydrogen, oxygen, nitrogen in some casesSome are toxic at relatively Co or only at Toxic Sulfurlow megadose levelslevels (6-10 times the RDA) (more than 10 timesExcess stored in the body Minimal storage of the RDA) dietary excessesAbsorbed into the lymphatic Absorbed into the bloodsystem than portal veinNeeded only by complex Needed by simple andorganisms complex organisms
• TOXICITY: - Hypervitaminosis A ~effects: birth defects, liver abnormalities, reduced bone mineral density that may result in osteoporosis, and central nervous system disorders. - Symptoms of overdose: (hydrocephalus), vomiting, tiredness, constipation, bone pain, and severe headaches. The skin may acquire a rough and dry appearance, with hair loss and brittle nails.• DEFICIENCY: – Night blindness – Keratomalacia – very dry, rough skin – decreased resistance to infections – faulty tooth development – slower bone growth• ABSORPTION: - absorbed into the intestine, and absorption remains high with increased intake - Vitamin A, which is fat-soluble, requires fat, as well as minerals, to be properly absorbed.
Vitamin D• OTHER NAME: "sunshine vitamin"CALCIFEROL, antirachitic factor, calcitriol, cholecalciferol (D3), ergocalciferol (D2)• FUNCTION: – The major biologic function of vitamin D is to maintain normal blood levels of calcium and phosphorus. – Vitamin D aids in the absorption of calcium, helping to form and maintain strong bones. – It promotes bone mineralization in concert with a number of other vitamins, minerals, and hormones. – It maintains normal cellular growth and function. – It maintains healthy immune function and preventing excessive inflammation. – It inhibits parathyroid hormone secretion from the parathyroid gland.
• TOXICITY: Vitamin D taken in excess can cause pathological changes in the body. Signs of vitamin D toxicity include loss of appetite, excessive thirst, irritability, excessive calcification of bone, kidney stones, calcification of soft tissue, headaches, weakness and weight loss, nausea, vomiting, constipation, polyuria, and polydipsia.• DEFICIENCY: - Rickets (in children) - Osteomalacia (in adults)• ABSORPTION: Vitamin D is best absorbed when ingested with lipids. Vitamin D will be incorporated into micelles and these will be absorbed by the intestine by passive diffusion. In the intestinal cells, chylomicrons will be formed, and these will enter the lymphatic system and enter the plasma. Vitamin D will then be transported to the liver by chylomicron remnants and to specific target with the help of carrier vitamin D binding protein (DBP) or transcalciferin.
Vitamin E (Tocopherol), antisterility factor• FUNCTIONS: • acts as an antioxidant, protecting vitamins A and C, red blood cells and essential fatty acids from destruction • help prevent heart disease and cancer. • Antioxidants such as vitamin E act to protect your cells against the effects of free radicals, which are potentially damaging by-products of energy metabolism. • have some anti-aging effects, both taken orally and applied on the skin. • Antioxidant (protects cells from toxic compounds, heavy metals, radiation, and free radicals); retinal development; protects vitamin A in eyes
• SOURCES: – Sunflower Seeds – Wheatgerm – Sesame Seeds – Peanuts – Vegetable oils – green leafy vegetables – fortified cereals• TOXICITY: • Megadoses of vitamin E may produce headaches, tiredness, double vision, and diarrhea in humans. • large doses of vitamin E consumed over many weeks or months might result in deficiencies of vitamin D, vitamin A, and vitamin K
• DEFICIENCY: – Vitamin E deficiency is usually characterized by neurological problems associated with nerve degeneration in hands and feet – Severe vitamin E deficiencies are rare. People with a genetic defect in a vitamin E transfer protein called thrombotic thrombocytopenic purpura (TTP) have severe vitamin E deficiency, characterized by low blood and tissue levels of vitamin E and progressive nerve abnormalities. – Severe: nausea, digestive tract disorders.• ABSORPTION: Approximately 20 to 60 per cent of dietary vitamin E is absorbed and it is stored in the • liver • heart • fatty tissues • muscles • testes • uterus • blood • adrenal • pituitary glands
Vitamin K• OTHER NAME: “Clotting vitamin”, anti- hemorrhagic vitamin/factor, coagulation factor, phylloquinone(K1), menaquinones (K2), menadione(K3)• FUNCTIONS: – plays an essential role in normal blood clotting – helps promote bone health – essential for the functioning of several proteins involved in blood clotting• SOURCES: – found in cabbage – cauliflower – spinach (green leafy vegetables) – cereals – soybeans – Vitamin K is also made by the bacteria that line the gastrointestinal tract.
• TOXICITY: – Prolonged consumption of megadoses of vitamin K (menadione) results in anemia – When large doses of menadione are given to infants, they result in the deposit of pigments in the brain, nerve damage, the destruction of red blood cells (hemolysis), and death.• DEFICIENCY: Vitamin K deficiency is manifest as a tendency to bleed excessively and bruising.• ABSORPTION: Vitamin K are absorbed into intestinal lymph along with other lipids.
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