"free radicals. At 323 kJ/mol, the O-H bond in tocopherols is about 10% weaker than in most other phenols. This weak bond allows the vitamin to donate a hydrogen atom to the peroxyl radical and other free radicals, minimizing their damaging effect. The thus-generated tocopheryl radical is recycled to tocopherol by a redox reaction with a hydrogen donor, such as vitamin C. As it is fat-soluble, vitamin E is incorporated into cell membranes, which are therefore protected from oxidative damage. Vitamin E affects gene expression and is an enzyme activity regulator, such as for protein kinase C (PKC) – which"
"usually in the form of the vitamin dissolved in vegetable oil in a softgel capsule. For alpha-tocopherol, amounts range from 100 to 1000 IU per serving. Smaller amounts are incorporated into multi-vitamin/mineral tablets. Gamma-tocopherol and tocotrienol supplements are also available from dietary supplement companies. The latter are extracts from palm or annatto oils. The World Health Organization does not have any recommendations for food fortification with vitamin E. The Food Fortification Initiative does not list any countries that have mandatory or voluntary programs for vitamin E. Infant formulas have alpha-tocopherol as an ingredient. In some countries, certain brands of ready-to-eat"
"industrial synthesis creates dl-alpha-tocopherol. ""It is synthesized from a mixture of toluene and 2,3,5-trimethyl-hydroquinone that reacts with isophytol to all-rac-alpha-tocopherol, using iron in the presence of hydrogen chloride gas as catalyst. The reaction mixture obtained is filtered and extracted with aqueous caustic soda. Toluene is removed by evaporation and the residue (all rac-alpha-tocopherol) is purified by vacuum distillation."" Specification for the ingredient is >97% pure. This synthetic dl-alpha-tocopherol has approximately 50% of the potency of d-alpha-tocopherol. Manufacturers of dietary supplements and fortified foods for humans or domesticated animals convert the phenol form of the vitamin to an ester using either"
"is purified by vacuum distillation."" Specification for the ingredient is >97% pure. This synthetic dl-alpha-tocopherol has approximately 50% of the potency of d-alpha-tocopherol. Manufacturers of dietary supplements and fortified foods for humans or domesticated animals convert the phenol form of the vitamin to an ester using either acetic acid or succinic acid because the esters are more chemically stable, providing for a longer shelf-life. The ester forms are de-esterified in the gut and absorbed as free alpha-tocopherol. During feeding experiments with rats Herbert McLean Evans concluded in 1922 that besides vitamins B and C, an unknown vitamin existed. Although every"
"(and eight possible stereoisomers per structural formula, again, only one of which occurs naturally). Each form has a different biological activity. In general, the unnatural l-isomers of tocotrienols lack almost all vitamin activity, and half of the possible 8 isomers of the tocopherols (those with 2S chirality at the ring-tail junction) also lack vitamin activity. Of the stereoisomers which retain activity, increasing methylation, especially full methylation to the alpha-form, increases vitamin activity. In tocopherols, this is due to the preference of the tocopherol binding protein for the alpha-tocopherol form of the vitamin. As a food additive, tocopherol is labeled with"
"the molecules water-soluble and leads to excretion via urine. Alpha-tocopherol is also degraded by the same process, to 2,5,7,8-tetramethyl-2-(2 ′-carboxyethyl)-6-hydroxychromane (α-CEHC), but more slowly because it is partially protected by α-TTP. Large intakes of α-tocopherol result in increased urinary α-CEHC, so this appears to be a means of disposing of excess vitamin E. Alpha-tocopherol transfer protein is coded by the TTPA gene on chromosome 8. The binding site for RRR-α-tocopherol is a hydrophobic pocket with a lower affinity for beta-, gamma-, or delta-tocopherols, or for the stereoisomers with an S configuration at the chiral 2 site. Tocotrienols are also a"
"Gamma-Tocotrienol γ-Tocotrienol (or ""gamma""-Tocotrienol) is one of the four types of tocotrienol, a type of vitamin E. Vitamin E exists in nature in eight forms, each of which consists of a head section joined to either a saturated (phytyl) or an unsaturated (farnesyl) tail. The four compounds with the saturated tails are the tocopherols, and the four compounds with the unsaturated tails are the tocotrienols. There are four unique dihydrocoumarin head sections, distinguished by one of four substitution patterns and designated as α, β, γ, or δ. The ""alpha-"" forms are distinguished by their three substituted methyl groups and the"
"hydroxylation step required for the formation of the physiologically active form of vitamin D, 1,25-dihydroxyvitamin D3. Alfacalcidol is an active vitamin D3 metabolite, and therefore does not require the second hydroxylation step in the kidney. Used as a poultry feed additive, it prevents tibial dyschondroplasia and increases phytate bioavailability. Pharmaceutical trade names include AlphaD and One-Alpha. Alfacalcidol Alfacalcidol (or 1-hydroxycholecalciferol) is an analogue of vitamin D used for supplementation in humans and as a poultry feed additive. Alfacalcidol has a weaker impact on calcium metabolism and parathyroid hormone levels than calcitriol, however alfacalcidol has significant effects on the immune system,"
"RRR vitamin activity, because they are recognized by the alpha-tocopherol transport protein, and thus maintained in the plasma, where the other four stereoisomers (SRR, SRS, SSR, and SSS) are not. Thus, the synthetic all-rac-α-tocopherol in theory would have approximately half the vitamin activity of RRR-alpha-tocopherol in humans. Experimentally, the ratio of activities of the 8 stereoisomer racemic mixture to the natural vitamin, is 1 to 1.36 in the rat pregnancy model (suggesting a measured activity ratio of 1/1.36 = 74% of natural, for the 8-isomer racemic mix). Although it is clear that mixtures of stereoisomers are not as active as"
"other fat malabsorption conditions can result in low serum vitamin E. Dietary supplements will raise serum vitamin E. Photosynthesizing plants, algae and cyanobacteria synthesize tocochromanols, the chemical family of compounds made up of four tocopherols and four tocotrienols; in a nutrition context this family is referred to as Vitamin E. Biosynthesis starts with formation of the closed-ring part of the molecule as homogentisic acid (HGA). The side chain is attached (saturated for tocopherols, polyunsaturated for tocotrienols). The pathway for both is the same, so that gamma- is created and from that alpha-, or delta- is created and from that the"
"Tocotrienol The vitamin E family comprise four tocotrienols (alpha, beta, gamma, delta) and four tocopherols (alpha, beta, gamma, delta). The critical chemical structural difference between tocotrienols and tocopherols is that tocotrienols have unsaturated isoprenoid side chains with three carbon-carbon double bonds versus saturated side chains for tocopherols (see Figure). Tocotrienols are compounds naturally occurring at higher levels in some vegetable oils, including palm oil, rice bran oil, wheat germ, barley, saw palmetto, annatto, and certain other types of seeds, nuts and grains, and the oils derived from them. Chemically, different analogues of vitamin E all show some activity as a"
"Alfacalcidol Alfacalcidol (or 1-hydroxycholecalciferol) is an analogue of vitamin D used for supplementation in humans and as a poultry feed additive. Alfacalcidol has a weaker impact on calcium metabolism and parathyroid hormone levels than calcitriol, however alfacalcidol has significant effects on the immune system, including regulatory T cells. It is considered to be a more useful form of vitamin D supplementation, mostly due to much longer half-life and lower kidney load. It is the most commonly prescribed vitamin D metabolite for patients with end stage renal disease, given that impaired renal function alters the ability to carry out the second"
"Cholecalciferol Cholecalciferol, also known as vitamin D and colecalciferol, is a type of vitamin D which is made by the skin when exposed to sunlight, it also found in some foods and can be taken as a dietary supplement. It is used to treat and prevent vitamin D deficiency and associated diseases, including rickets. It is also used for familial hypophosphatemia, hypoparathyroidism that is causing low blood calcium, and Fanconi syndrome. It is usually taken by mouth. Excessive doses can result in vomiting, constipation, weakness, and confusion. Other risks include kidney stones. Normal doses are safe in pregnancy. It may"
"""delta-"" forms by their one substituted methyl group. The ""beta-"" and ""gamma-"" forms both have two substituted methyl groups, although at different structural positions (5,8-dimethyl and 7,8-dimethyl, respectively), making both ""beta"" / ""gamma"" tocotrienol as well as the ""beta"" / ""gamma"" tocopherol pairs of stereoisomer. Gamma-Tocotrienol γ-Tocotrienol (or ""gamma""-Tocotrienol) is one of the four types of tocotrienol, a type of vitamin E. Vitamin E exists in nature in eight forms, each of which consists of a head section joined to either a saturated (phytyl) or an unsaturated (farnesyl) tail. The four compounds with the saturated tails are the tocopherols, and"
"these molecules that tocotrienols do not have). Tocotrienol has been subject to fewer clinical studies and seen less research as compared to tocopherol. However, there is growing interest in the health effects of these compounds. Tocopherols are radical scavengers, delivering an H atom to quench free radicals. At 323 kJ/mol, the O-H bond in tocopherols is about 10% weaker than in most other phenols. This weak bond allows the vitamin to donate a hydrogen atom to the peroxyl radical and other free radicals, minimizing their damaging effect. The thus generated tocopheryl radical is relatively unreactive but revert to tocopherol by"
"the glutathione-ascorbate cycle, glutathione peroxidases and glutaredoxins, as well as reacting directly with oxidants. Due to its high concentration and its central role in maintaining the cell's redox state, glutathione is one of the most important cellular antioxidants. In some organisms glutathione is replaced by other thiols, such as by mycothiol in the Actinomycetes, bacillithiol in some Gram-positive bacteria, or by trypanothione in the Kinetoplastids. Vitamin E is the collective name for a set of eight related tocopherols and tocotrienols, which are fat-soluble vitamins with antioxidant properties. Of these, α-tocopherol has been most studied as it has the highest bioavailability,"
"are essential for renewing the body's supply of blood cells. Based on these successful results of studies in mice, γ-tocotrienol is being studied for its safety and efficacy as a radioprotective measure in nonhuman primates. Tocotrienol The vitamin E family comprise four tocotrienols (alpha, beta, gamma, delta) and four tocopherols (alpha, beta, gamma, delta). The critical chemical structural difference between tocotrienols and tocopherols is that tocotrienols have unsaturated isoprenoid side chains with three carbon-carbon double bonds versus saturated side chains for tocopherols (see Figure). Tocotrienols are compounds naturally occurring at higher levels in some vegetable oils, including palm oil, rice"
"chiral center, but unlike synthetic, dl-alpha-tocopherol, the marketed tocotrienol dietary supplements are all d-tocotrienol extracts from palm or annatto oils. Tocotrienol studies confirm anti-oxidation, anti-inflammatory potentials and suggest anti-cancer effects than the common forms of tocopherol due to their chemical structure. Scientists have suggested tocotrienols are better antioxidants than tocopherols. It has been proposed that the unsaturated side-chain in tocotrienols causes them to penetrate tissues with saturated fatty layers more efficiently than tocopherol. Lipid ORAC values are highest for δ-tocotrienol. However that study also says: ""Regarding α-tocopherol equivalent antioxidant capacity, no significant differences in the antioxidant activity of all vitamin"
"amino acids. Most vitamins are not single molecules, but groups of related molecules called vitamers. For example, vitamin E consists of four tocopherols and four tocotrienols. The thirteen vitamins required by human metabolism are: vitamin A (retinols and carotenoids), vitamin B (thiamine), vitamin B (riboflavin), vitamin B (niacin), vitamin B (pantothenic acid), vitamin B (pyridoxine), vitamin B (biotin), vitamin B (folic acid or folate), vitamin B (cobalamins), vitamin C (ascorbic acid), vitamin D (calciferols), vitamin E (tocopherols and tocotrienols), and vitamin K (quinones). Vitamins have diverse biochemical functions. Some forms of vitamin A function as regulators of cell and tissue"
"Vitamin D Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and multiple other biological effects. In humans, the most important compounds in this group are vitamin D (also known as cholecalciferol) and vitamin D (ergocalciferol). Cholecalciferol and ergocalciferol can be ingested from the diet and from supplements. Only a few foods contain vitamin D. The major natural source of the vitamin is synthesis of cholecalciferol in the skin from cholesterol through a chemical reaction that is dependent on sun exposure (specifically UVB radiation). Dietary recommendations typically assume that all of"
"E increased all-cause mortality. The U.S. Food and Nutrition Board set a Tolerable upper intake level (UL) at 1,000 mg (1,500 IU) per day derived from animal models that demonstrated bleeding at high doses. The European Food Safety Authority reviewed the same safety question and set a UL at 300 mg/day. A meta-analysis of long-term clinical trials reported a non-significant 2% increase in all-cause mortality when alpha-tocopherol was the only supplement used. The same meta-analysis reported a statistically significant 3% increase for results when alpha-tocopherol was used by itself or in combination with other nutrients (vitamin A, vitamin C, beta-carotene,"
"are three (1,3,25-triol), as indicated in when ""calcitriol"" is used. The 1-hydroxy group is in the alpha position, and this may be specified in the name, for instance in the abbreviation 1α,25-(OH)D. Calcitriol is the strictly the 1-hydroxylation product of calcifediol (25-OH vitamin D), derived from cholecalciferol (vitamin D), rather than the product of hydroxylations of ergocalciferol (vitamin D). 1α,25-Dihydroxyergocalciferol (ercalcitriol) should be used for the vitamin D product. However, the terminology of 1,25-dihydroxyvitamin D, or 1,25(OH)D, is often used to refer to both types of active forms of vitamin D. Indeed, both bind to the vitamin D receptor and"
"depending on age. India recommends an intake of 8–10 mg/day and does not set a UL. The World Health Organization recommends that adults consume 10 mg/day. Consumption is below government recommendations. A worldwide summary of more than one hundred studies reported a median dietary intake of 6.2 mg/d for alpha-tocopherol. Government survey results in the U.S. reported average consumption for adult females at 8.4 mg/d and adult males 10.4 mg/d. Both are both below the RDA of 15 mg/day. For U.S. food and dietary supplement labeling purposes the amount in a serving is expressed as a percent of Daily Value"
"Calcitriol Calcitriol (INN), also called 1,25-dihydroxycholecalciferol, or 1alpha,25-dihydroxyvitamin D3, 1,25-dihydroxyvitamin D and other variants, is the hormonally active metabolite of vitamin D which has three hydroxyl groups. It can be abbreviated 1α,25-(OH)D or simply 1,25(OH)D. Calcitriol increases the level of calcium (Ca) in the blood by increasing the uptake of calcium from the gut into the blood, increasing reabsorption of calcium by the kidneys, and possibly increasing the release of calcium into the blood from bone. Calcitriol usually refers specifically to 1,25-dihydroxycholecalciferol. Because cholecalciferol already has one hydroxyl group, only two (1,25) are further specified in this nomenclature, but there"
"consensus is that supplementing levels is not beneficial. It is thought that tuberculosis may result in lower levels. It, however, is not entirely clear how the two are related. Cholecalciferol is one of the five forms of vitamin D. Cholecalciferol is a secosteroid, that is, a steroid molecule with one ring open. By itself cholecalciferol is inactive. It is converted to its active form by two hydroxylations: the first in the liver, by CYP2R1 or CYP27A1, to form 25-hydroxycholecalciferol (calcifediol, 25-OH vitamin D). The second hydroxylation occurs mainly in the kidney through the action of CYP27B1 to convert 25-OH vitamin"
"Tocofersolan Tocofersolan (INN) or tocophersolan is a synthetic water-soluble version of vitamin E. Natural forms of vitamin E are fat soluble, but not water-soluble. Tocofersolan is polyethylene glycol derivative of α-tocopherol that enables water solubility. Tocofersolan is used as a vitamin E supplement or to treat vitamin E deficiency in individuals who cannot absorb fats due to disease. On 24 July 2009 the European Medicines Agency approved tocofersolan under the trade name Vedrop 50 mg/ml oral solution for the treatment of vitamin E deficiency due to digestive malabsorption in paediatric patients suffering from congenital or hereditary chronic cholestasis, from birth"
"chemical antioxidant, but do not all have the same vitamin E equivalence. Tocotrienols demonstrate activity depending on the type of antioxidant performance being measured. All tocotrienols have some physical antioxidant activity due to an ability to donate a hydrogen atom (a proton plus electron) from the hydroxyl group on the chromanol ring, to free radical and reactive oxygen species. Historically studies of tocotrienols account for less than 1% of all research into vitamin E. A scientific compilation of tocotrienol research, ""Tocotrienols: Vitamin E Beyond Tocopherols"", was published in 2013. A number of health benefits of tocotrienols have been proposed, included"
"a hormone involved in morphogenesis. Vitamin D Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and multiple other biological effects. In humans, the most important compounds in this group are vitamin D (also known as cholecalciferol) and vitamin D (ergocalciferol). Cholecalciferol and ergocalciferol can be ingested from the diet and from supplements. Only a few foods contain vitamin D. The major natural source of the vitamin is synthesis of cholecalciferol in the skin from cholesterol through a chemical reaction that is dependent on sun exposure (specifically UVB radiation). Dietary recommendations"
"the possibility of tumor protection from the oxidative damage intended by the treatments. Naturally sourced d-alpha-tocopherol can be extracted and purified from seed oils, or gamma-tocopherol can be extracted, purified, and methylated to create d-alpha-tocopherol. In contrast to alpha-tocopherol extracted from plants, which is also called d-alpha-tocopherol, industrial synthesis creates dl-alpha-tocopherol. ""It is synthesized from a mixture of toluene and 2,3,5-trimethyl-hydroquinone that reacts with isophytol to all-rac-alpha-tocopherol, using iron in the presence of hydrogen chloride gas as catalyst. The reaction mixture obtained is filtered and extracted with aqueous caustic soda. Toluene is removed by evaporation and the residue (all rac-alpha-tocopherol)"
"because the body requires them for good health but cannot synthesize them. Only two fatty acids are known to be essential for humans: alpha-linolenic acid (an omega-3 fatty acid) and linoleic acid (an omega-6 fatty acid). Vitamins are organic molecules essential for an organism that are not classified as amino acids or fatty acids. They commonly function as enzymatic cofactors, metabolic regulators or antioxidants. Humans require thirteen vitamins in their diet, most of which are actually groups of related molecules (e.g. vitamin E includes tocopherols and tocotrienols): vitamins A, C, D, E, K, thiamine (B), riboflavin (B), niacin (B), pantothenic"
"who studied AFA's fat content concluded that AFA ""should be a valuable nutritional resource."" AFA raises the blood levels of the good fatty acids more than would be expected based on its ALA content alone. They speculated that some micronutrients may enhance fatty acid utilization. The levels of ""good"" fatty acids (ALA, EPA, DHA) went up while the levels of arachidonic acid went down. Chlorophyll is the green pigment found in plants that is responsible for the production of oxygen through the process of photosynthesis. Chlorophyll is a significant phytonutrient as well as a powerful antioxidant. AFA contains 1 to"
"Alpha-fetoprotein Alpha-fetoprotein (AFP, α-fetoprotein; also sometimes called alpha-1-fetoprotein, alpha-fetoglobulin, or alpha fetal protein) is a protein that in humans is encoded by the ""AFP"" gene. The ""AFP"" gene is located on the ""q"" arm of chromosome 4 (4q25). AFP is a major plasma protein produced by the yolk sac and the fetal liver during fetal development. It is thought to be the fetal analog of serum albumin. AFP binds to copper, nickel, fatty acids and bilirubin and is found in monomeric, dimeric and trimeric forms. AFP is a glycoprotein of 591 amino acids and a carbohydrate moiety. AFP is the"
"(BMD) of vegans was 94 percent that of omnivores, but deemed the difference clinically insignificant. Vitamin D (calciferol) is needed for several functions, including calcium absorption, enabling mineralization of bone, and bone growth. Without it bones can become thin and brittle; together with calcium it offers protection against osteoporosis. Vitamin D is produced in the body when ultraviolet rays from the sun hit the skin; outdoor exposure is needed because UVB radiation does not penetrate glass. It is present in salmon, tuna, mackerel and cod liver oil, with small amounts in cheese, egg yolks, and beef liver, and in some"