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Vitamins: Essential organic compounds needed in very small amounts in the diet to help regulate and support chemical reactions in the body. Vitamins can be classified based on their solubility. Water soluble vitamins are the B and C vitamins and fat soluble vitamins are vitamins A,D, E and K to be classified as a vitamin, a compound must meet these two criteria. First, the body must be unable to synthesize enough of the compound to maintain health; second, the absence of the compound from the diet for a defined period produces deficiency symptoms that can be cured by resupplying the compound if it is caught in time. A few vitamins have also proved useful in treating general non deficiency dyeages as well. This occurs when vitamins are tokenized in megadoses.Don't forget about the age old question of What is "slave power conspiracy?"
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Saturation: The degree to which tissue vitamins stores are full (tissue storage capacity is limited). Toxicity is prevented by increasing kidney excretion rates when tissues become saturated.However B-6 and B-12 are stored in the liver and are not easily excreted. Even though tissues become saturated, these vitamins should be taken daily.If you want to learn more check out What does the dream of the rood mean?
Coenzyme: Compound that combines with an inactive enzyme to form a catalytically active from. In this manner, coenzymes did in enzyme function.Don't forget about the age old question of What is point and interval prediction?
Bioavailability: Degree to which a consumed nutrients is absorbed and used by the body
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Toxicity: Although all fat soluble and B-6 and B-12 are subject to toxicity. Toxicity of vitamin A is most frequently observed. It carries toxicity at intakes us little as two times the RDA while most other vitamins cause toxicity only, when consumed in large amounts (15 to 100 times the human needs) . Vitamins are unlikely to cause toxic effects unless taken in supplement (pill) form.
Vitamins can be found in all food groups, especially fruits and vegetables. However, storage time and several environmental factors can affect vitamin, contest of foods. Therefore, it is best to eat fresh produce as soon as possible after harvest, other factors that can destroy vitamins include heat, light, air exposure, cooking in water and alkalinity. If a food is not to be eaten within a few days of harvest, freezing is the best preparation method to retain nutrients.
Vitamin A: First recognized fat soluble vitamin 90% of it is stored in the liver. Either a deficiency or a toxicity can be detrimental to health, so there is a narrow range of intakes between these two states vitamin A is in a group called retinoids. These are three active forms of vitamin A: retinol, retinal and retinol acid. These are often called preformed vitamin A and exist only in animal products when retinol is stored. It is often esterified and becomes retinyl. Plants content payments called carotenoids, which are phytochemicals that are precursors of vitamin A. They have profound antioxidant properties. They are often called provitamin A since they can be converted into Vitamin A. Three carotenoids can be converted into provitamin A, alpha-carotene, beta-carotene and beta cryptoxanthin, but these , only beta carotene can be sufficiently converted and absorbed to play a significant role as a vitamin A source.
Vitamin A maintains the health of epithelial cells, intestines, bladder, vagina, urinary tract, skin and eyes without vitamin A, epithelial cells cannot mature and intestine and lung cells deteriorate. For the eye, this can lead to blindness. Epithelial cells tissues serve as barriers to infection, vitamin A also supports the activity of some immune cells such as the T-cells. Immune response improves when supplemented with Vitamin A. So it is sometimes called the anti-infection vitamin.
Vitamin A performs important functions in light-dark vision and a little in color vision,too. Light entering the eye reaches the retina, the lining in the back of the eyes, that consists of rod, colle and nerve cells. Rod cells detect black and white light and are responsible for night vision, cone cells are responsible for color vision. Rod cells require Vitamin A for normal function. Retinal allows cells to adjust to dim light without vitamin A, night blindness-loss the ability to see under low light conditions occurs. Some provitamin A carotenoids are also important for vision, they can lower the risk of age related macular degeneration-disruption of the central part of the retina that leads to blurred vision.Carotenoids may also reduce the risk of cataracts. However, carotenoids should be consumed via food sources such as green leafy vegetables, and not via supplements
Carotenoids may play a role in preventing cardiovascular disease in persons at high risk, This role may be linked to their ability to inhibit the oxidation LDLs
Vitamin A participates in growth, development, and reproduction. They can increase synthesis of proteins, mature and differentiate cells, and breakdown old bone to new bone can be formed without enough vitamin A, growth and reproduction are stunted.
Vitamin A carotenoids may also be a possible cancer preventive. Preventing cancer may be a by-product of their antioxidant activity. Numerous studies associate carotenoids with a lower risk of skin, lung, bladder, breast and prostate cancers.
If Vitamin A deficiency continues past night blindness, the coined loses its mucus-producing ability, drying out of the eyes and causing xerophthalmia-hardening of the corner and drying in the surface of the eye which can lead to blindness. Vitamin A deficiency is the leading case of worldwide blindness. Children are greatly at risk and diagnosed. Developing nations are also at greater risk.
Preformed Vitamin A is found in liver, fish, fish oils and dairy products. Preformed Vitamin A makes up most of the american diet. Provitamin A carotenoids are mainly found in dark green and yellow orange vegetables and from fruits.
Intakes above the UL for vitamin A are linked to birth defects and liver toxicity, during the early months of pregnancy, a high intake of preformed vitamin A is dangerous because if can cause fetal, malformations and spontaneous abortions. However, dietary carotenoids do not produce toxic effects because the rate of conversion with vitamin A is slow and because the efficiency of its absorption decreases as oral intake increases.
Hormone: compound manufactured by one organ or tissue that enters the bloodstream and has a physiological effect on another organ or tissue in the body.
Vitamin D: a fat soluble vitamin that has two unique qualities, it is the only nutrient that is also a hormone and it is the only nutrient that can be produced in the skin upon exposure to ultraviolet light.
First, ultraviolet B (UVB) rays convert a cholesterol precursor of vitamin D found in the skin to an inactive form of Vitamin D that can be activated in the liver, and then the kidney before it can function as a hormone. Our ability to absorb UVB rays and synthesize vitamin B is affected by many things including age. Skin pigment, time, season , and weather. Age and darker skin decreased absorption.
Vitamin D is also colatriol
Vitamin D’s main function is to maintain and regulate calcium and phosphorus levels in the blood vitamin D tightly regulates calcium levels along with parathyroid hormone (PTH) to ensure all cells get an appropriate amount of calcium. It regulates calcium in three ways. It influences the absorption of calcium in the small intestine, regulates calcium excretion via the kidney with the help of calcitonin and PTH, and affects the deposition of withdrawal of minerals from the bones.
Vitamin D also functions in cell growth and gene expression. It binds to (and thus affects) immune system, brain and nervous system cells, the parathyroid gland, pancreas, skin, muscles and reproductive organs. By influencing normal development in many cell types, Vitamin D reduces the risk of cancer at these sites. Vitamin D may also prevent many chronic diseases including diabetes, hypertension and cardiovascular disease.
When Vitamin D deficiency occurs at infant or adolescent age, it produces rickets skeletal abnormalities including bowed legs, spine, curvature, pigeon chest, skull malformation and pelvic deformities. Osteomalacia is the adult disease of deficiency comparable to rickets; it can result from insufficient intake, absorption or conservation (via the kidney). Osteomalacia means soft bone, disease leads to a decrease in bone mineral density. Bones become porous and weak and break easily.
There are two forms of Vitamin D: Vitamin D2 (erdocalterol) and Vitamin D3 (cholecalciferol). Vitamin D3 is more commonly used in supplements. Vitamin D 3 is also the form synthesized in the human body. Both forms must be modified in the kidney and liver before they become active in the body.
Fortified foods such as fortified milk and ready to eat cereals as well as supplements contain good amounts of Vitamin D. Vitamin D is necessary during growth and development in order to support optimal bone mineralization
High doses of Vitamin D can cause calcium levels in the blood to increase above the normal range. It can carry calcium deposits in the kidney and in other organs which can cause metabolic disturbances and cell death. Toxicity symptoms include weakness, appetite logs, diarrhea, vomiting, increased urine output and confusion
Vitamin E is a fat soluble vitamin found primarily in adipose tissues and the lipid bilayers of cell membranes where it functions as an antioxidant. Donating electrons or hydrogens to polyunsaturated fatty acids within membranes that are susceptible to oxidative attack by free radicals,which could destabilize the cell membrane and affect cell function. This antioxidant function is particularly important for cells that are continually exposed to oxygen, such as red blood cells lining the lung increasing vitamin E intake is suggested as a way to prevent several chronic diseases that are linked to oxidative damage such as cataracts and atherosclerosis.
Vitamin E is essential for fertility in many animals, but not in humans. It does however function in muscle and central nervous system formation in early human development. It also may improve vitamin A absorption if vitamin A levels are low. Furthermore, it functions in iron metabolism and maintain nervous tissue and immune function
Because stores of Vitamin E are transferred from mother to baby late in gestation, premature infants are of risk of Vitamin E deficiency and hemolysis, the breaking of red blood cells, is a concern for such infants. This can be reversed by special vitamin E fortified formulas. Smokers are also at risk for this deficiency because smoking destroys Vitamin E in the lungs. Last, Adults on low fat diets or those with fat malabsorption are also at risk.
Vitamin E is only synthesized by plants, so plant products- especially oils are the best sources. Grains are poor sources because milling of grains removes the germ, which contains the vitamin E. The vitamin E content of a food depends on how it is harvested, processed, stored, and cooked. Animal products contain almost no vitamin E.
Excess vitamin E is stored in the adipose tissue, not in the liver. Excess intake of Vitamin E can interfere with vitamin K’s blood clotting role, leading to hemorrhaging irt can also produce nausea, GI distress and diarrhea.
Vitamin K is a family of compounds collectively found in plants, plant oils,fish oils and animal products. It is also called quinone K, stands for coagulation in Danish, noting that vitamin K plays a role in blood clotting; it serves as a cofactor that can add CO2 to seven different proteins, enabling them to bind to calcium, transforming them into active clothing factors. Because of its role in blood clotting, it is also important for bone three calcium binding proteins in the bones depend on vitamin K for these functions in bone mineralization
Vitamin K injections are commonly given to newborns shortly after birth. This is because in adults, bacteria in the colon can produce Vitamin K but newborns have sterile guts: guts lacking bacteria. Adults on antibodies for long periods of time can also be at risk for a deficiency because antibodies can wipe out bacteria in the gut.
Vitamin K is found in plant products, specifically green vegetables. It can also be found in dairy products, but never really in animal products, unlike other fat soluble vitamins it is not stored for long amounts of time and excreted via urine if in excess. No toxicity has ever been reported.
Regular consumption of water soluble vitamins is important because very small amounts, if any, are stored in the body. Furthermore, they dissolve in water so they are easily lost during food processing and preparation. Then B vitamins are often found in the same foods, so a deficiency of one likely means a deficiency of other B vitamins. B vitamins function as coenzymes- small molecules that interact with enzymes that activate them, enabling them to function. Therefore, they play key roles in metabolism.
This needs for B vitamins increases as energy expenditure increases.B vitamin deficiency symptoms usually occur in the brain and nervous system. CI tract, and skin because these tissues are metabolically active and/or constantly being replaced.