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Maret G Traber - One of the best experts on this subject based on the ideXlab platform.
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A history of Vitamin E.
Annals of Nutrition and Metabolism, 2012Co-Authors: Etsuo Niki, Maret G TraberAbstract:Vitamin E (α-tocophErol) was discovErEd nEarly 100 yEars ago bEcausE it was rEquirEd to prEvEnt fEtal rEsorption in prEgnant, Vitamin E-dEficiEnt rats fEd lard-containing diEts that wErE Easily oxidizablE. ThE human diEt contains Eight diffErEnt Vitamin E-rElatEd molEculEs synthEsizEd by plants; dEspitE thE fact that all of thEsE molEculEs arE pEroxyl radical scavEngErs, thE human body prEfErs α-tocophErol. ThE biological activity of Vitamin E is highly dEpEndEnt upon rEgulatory mEchanisms that sErvE to rEtain α-tocophErol and ExcrEtE thE non-α-tocophErol forms. This prEfErEncE is dEpEndEnt upon thE combination of thE function of α-tocophErol transfEr protEin (α-TTP) to Enrich thE plasma with α-tocophErol and thE mEtabolism of non-α-tocophErols. α-TTP is critical for human hEalth bEcausE mutations in this protEin lEad to sEvErE Vitamin E dEficiEncy charactErizEd by nEurologic abnormalitiEs, EspEcially ataxia and EvEntually dEath if Vitamin E is not providEd in largE quantitiEs to ovErcomE thE lack of α-TTP. α-TocophErol sErvEs as a pEroxyl radical scavEngEr that protEcts polyunsaturatEd fatty acids in mEmbranEs and lipoprotEins. Although spEcific pathways and spEcific molEcular targEts havE bEEn sought in a variEty of studiEs, thE most likEly Explanation as to why humans rEquirE Vitamin E is that it is a fat-solublE antioxidant.
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Vitamin E rEgulatory mEchanisms
Annual Review of Nutrition, 2007Co-Authors: Maret G TraberAbstract:AbstractDiEtary and supplEmEntal Vitamin E is absorbEd and dElivErEd to thE livEr, but of thE various antioxidants with Vitamin E activity, only α-tocophErol is prEfErEntially rEcognizEd by thE α-tocophErol transfEr protEin (α-TTP) and is transfErrEd to plasma, whilE thE othEr Vitamin E forms (E.g., γ-tocophErol or tocotriEnols) arE rEmovEd from thE circulation. HEpatic α-TTP is rEquirEd to maintain plasma and tissuE α-tocophErol concEntrations. ThE livEr is thE mastEr rEgulator of thE body's Vitamin E lEvEls in that it not only controls α-tocophErol concEntrations, but also appEars to bE thE major sitE of Vitamin E mEtabolism and ExcrEtion. Vitamin Es arE mEtabolizEd similarly to xEnobiotics; thEy arE initially ω-oxidizEd by cytochromE P450s, undErgo sEvEral rounds of β-oxidation, and thEn arE conjugatEd and ExcrEtEd. As a rEsult of thEsE various mEchanisms, livEr α-tocophErol and othEr Vitamin E concEntrations arE closEly rEgulatEd; thus, any potEntial advErsE Vitamin E EffEcts arE limitEd.
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Vitamin E REgulatory MEchanisms
Annual Review of Nutrition, 2007Co-Authors: Maret G TraberAbstract:DiEtary and supplEmEntal Vitamin E is absorbEd and dElivErEd to thE livEr, but of thE various antioxidants with Vitamin E activity, only alpha-tocophErol is prEfErEntially rEcognizEd by thE alpha-tocophErol transfEr protEin (alpha-TTP) and is transfErrEd to plasma, whilE thE othEr Vitamin E forms (E.g., gamma-tocophErol or tocotriEnols) arE rEmovEd from thE circulation. HEpatic alpha-TTP is rEquirEd to maintain plasma and tissuE alpha-tocophErol concEntrations. ThE livEr is thE mastEr rEgulator of thE body's Vitamin E lEvEls in that it not only controls alpha-tocophErol concEntrations, but also appEars to bE thE major sitE of Vitamin E mEtabolism and ExcrEtion. Vitamin Es arE mEtabolizEd similarly to xEnobiotics; thEy arE initially omEga-oxidizEd by cytochromE P450s, undErgo sEvEral rounds of bEta-oxidation, and thEn arE conjugatEd and ExcrEtEd. As a rEsult of thEsE various mEchanisms, livEr alpha-tocophErol and othEr Vitamin E concEntrations arE closEly rEgulatEd; thus, any potEntial advErsE Vitamin E EffEcts arE limitEd.
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Vitamin E in humans dEmand and dElivEry
Annual Review of Nutrition, 1996Co-Authors: Maret G Traber, Helmut SiesAbstract:How much Vitamin E is Enough? An EstablishEd usE of supplEmEntal Vitamin E in humans is in thE prEvEntion and thErapy of dEficiEncy symptoms. ThE causE of Vitamin E dEficiEncy, charactErizEd by pEriphEral nEuropathy and ataxia, is usually malabsorption—a rEsult of fat malabsorption or gEnEtic abnormalitiEs in lipoprotEin mEtabolism. GEnEtic abnormalitiEs in thE hEpatic α-tocophErol transfEr protEin also causE Vitamin E dEficiEncy—dEfEcts in this protEin causE an impairmEnt in plasma Vitamin E transport. ImpairEd dElivEry of Vitamin E to tissuEs, thErEby, rEsults in dEficiEncy symptoms. Also discussEd is thE usE of supplEmEntal Vitamin E in chronic disEasEs such as ischEmic hEart disEasE, athErosclErosis, diabEtEs, cataracts, Parkinson's disEasE, AlzhEimEr's disEasE, and imparEd immunE function, as wEll as in subjEcts rEcEiving total parEntErol nutrition. In hEalthy individuals, a daily intakE of about 15-30 mg of α-tocophErol is rEcommEndEd to obtain “optimal plasma alpha-tocophErol concEntrations” (30 μM...
Lin Hui-jing - One of the best experts on this subject based on the ideXlab platform.
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DEtErmination of NaturE Vitamin E in NaturE Vitamin E Soft CapsulEs by HPLC
Pharmacy Today, 2020Co-Authors: Lin Hui-jingAbstract:ObjEctivE To Establish a HPLC mEthod for thE dEtErmination of naturE Vitamin E in naturE Vitamin E soft capsulEs. MEthods ThE HPLC mEthod was adoptEd.ThE column is AgilEnt-C 18(250 mm×4.6 mm,5 μm).ThE mobilE phasE was mEthanol,at a flow ratE of 1.0 ml/min,and thE dEtEcting wavElEngth was at 291 nm.REsults ThE linEar rangE was 0.05~1.00 mg/ml(r =1.0000),thE avEragE rEcovEry(n= 9) was 100.2%(RSD=1.1%).Conclusion ThE mEthod is simplE,fast,and rEliablE.It is an EffEctivE mEthod for thE dEtErmination of naturE Vitamin E in Vitamin E soft capsulEs.
Anne P. Spencer - One of the best experts on this subject based on the ideXlab platform.
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Vitamin E: cautionary issuEs
Current Treatment Options in Cardiovascular Medicine, 2000Co-Authors: Anne P. SpencerAbstract:ComparEd with many mEdications usEd in thE patiEnt with cardiovascular disEasE, Vitamin E is a rElativEly safE supplEmEnt. ThErE arE a fEw populations in which caution nEEds to bE EmployEd, howEvEr. PatiEnts rEcEiving warfarin thErapy should bE discouragEd from using Vitamin E supplEmEnts and should bE closEly monitorEd if thEy do. SmokErs should avoid Vitamin E duE to potEntial nEgativE EffEcts on Vitamin C, and Vitamin E should nEvEr bE administErEd in conjunction with bEta-carotEnE in this population. ThE rarE patiEnt rEquiring Vitamin A thErapy or having rEtinitis pigmEntosa should also avoid Vitamin E supplEmEntation. BEcausE of thE incrEasEd risk of blEEding, Vitamin E should bE discontinuEd in thE pEriopErativE pEriod in any patiEnt rEquiring surgEry.
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Vitamin E: Cautionary IssuEs.
Current Treatment Options in Cardiovascular Medicine, 2000Co-Authors: Anne P. SpencerAbstract:ComparEd with many mEdications usEd in thE patiEnt with cardiovascular disEasE, Vitamin E is a rElativEly safE supplEmEnt. ThErE arE a fEw populations in which caution nEEds to bE EmployEd, howEvEr. PatiEnts rEcEiving warfarin thErapy should bE discouragEd from using Vitamin E supplEmEnts and should bE closEly monitorEd if thEy do. SmokErs should avoid Vitamin E owing to potEntial nEgativE EffEcts on Vitamin C, and Vitamin E should nEvEr bE administErEd in conjunction with bEta-carotEnE in this population. ThE rarE patiEnt rEquiring Vitamin A thErapy or having rEtinitis pigmEntosa should also avoid Vitamin E supplEmEntation. BEcausE of thE incrEasEd risk of blEEding, Vitamin E should bE discontinuEd in thE pEriopErativE pEriod in any patiEnt rEquiring surgEry.
Helmut Sies - One of the best experts on this subject based on the ideXlab platform.
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Vitamin E in humans dEmand and dElivEry
Annual Review of Nutrition, 1996Co-Authors: Maret G Traber, Helmut SiesAbstract:How much Vitamin E is Enough? An EstablishEd usE of supplEmEntal Vitamin E in humans is in thE prEvEntion and thErapy of dEficiEncy symptoms. ThE causE of Vitamin E dEficiEncy, charactErizEd by pEriphEral nEuropathy and ataxia, is usually malabsorption—a rEsult of fat malabsorption or gEnEtic abnormalitiEs in lipoprotEin mEtabolism. GEnEtic abnormalitiEs in thE hEpatic α-tocophErol transfEr protEin also causE Vitamin E dEficiEncy—dEfEcts in this protEin causE an impairmEnt in plasma Vitamin E transport. ImpairEd dElivEry of Vitamin E to tissuEs, thErEby, rEsults in dEficiEncy symptoms. Also discussEd is thE usE of supplEmEntal Vitamin E in chronic disEasEs such as ischEmic hEart disEasE, athErosclErosis, diabEtEs, cataracts, Parkinson's disEasE, AlzhEimEr's disEasE, and imparEd immunE function, as wEll as in subjEcts rEcEiving total parEntErol nutrition. In hEalthy individuals, a daily intakE of about 15-30 mg of α-tocophErol is rEcommEndEd to obtain “optimal plasma alpha-tocophErol concEntrations” (30 μM...
Sun Xin-jian - One of the best experts on this subject based on the ideXlab platform.
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DEtErmination thE contEnt of Vitamin E in Vitamin E soft capsulEs by GC-MS
Chinese Journal of Hospital Pharmacy, 2020Co-Authors: Sun Xin-jianAbstract:OBJECTIVE To Establish a mEthod for dEtErmining thE contEnt of Vitamin E in Vitamin E soft capsulE by GC/MS.METHODS ThE GC/MS was EquippEd with a mass dEtEctor.A chromatographic column(30 m×0.32 mm,0.25 μm)with DB-5MS was adoptEd.ThE carriEr gas was hElium.ThE m/z was 430.ThE assay of Vitamin E was calculatEd according to thE ExtErnal standard mEthod.RESULTS Vitamin E is dEtEctEd in thE samplE of Vitamin E soft capsulE.ThE standard curvEs wErE linEar within thE rangEs of 0.01-10 mg· L-1(r=0.9998,n=6).ThE avEragE rEcovEriEs wErE 100.3%(RSD=1.06%,n=5).ThE limits of dEtEction wErE 10 pg.CONCLUSION This mEthod appEars to bE sEnsitivE,accuratE,rEpEatablE,Easy to opEratE and can bE usEd for thE quality control of Vitamin E soft capsulEs.
