I-Retinol (Vitamin A) ivithamini elincibilika ngamafutha kanye ne-antioxidant. Itholakala ekudleni kokuvela kwezitshalo nezilwane. Emzimbeni womuntu, i-retinol yakhiwa nge-beta-carotene.
Umlando kavithamini
IVitamin A yathola igama layo ngenxa yokuthi yatholwa kuqala kunezinye futhi yaba ngumnikazi wohlamvu lokuqala lwezinhlamvu zesiLatini esiqokweni. Ngo-1913, amaqembu amabili azimele ososayensi abasesimweni selabhoratri athola ukuthi ngaphezu kokudla okulinganiselayo ngama-carbohydrate kanye namaprotheni, umzimba udinga ezinye izingxenye ezingeziwe, ngaphandle kwalapho ukuthembeka kwesikhumba kwephulwa, umbono uyancipha futhi umsebenzi wazo zonke izitho zangaphakathi uhlakazekile.
Kukhonjwe amaqembu amabili abalulekile ezakhi. Elokuqala lalibizwa ngokuthi yiqembu A. Lalihlanganisa i-retinol eyakhiwe, i-tocopherol ne-calciferol. Iqembu lesibili, ngokulandelana, labizwa ngeB. Lalifaka izinto eziningi ezinezici ezifanayo. Ngemuva kwalokho, leli qembu lalekelelwa ngezikhathi ezithile, futhi ezinye zezakhi zalo, ngemuva kwesifundo eside, zasuswa ngokuphelele kulo. Kungakho kunevithamini B12 kepha kungekho B11.
Umsebenzi wesikhathi eside wokuhlonza izakhiwo eziwusizo ze-retinol unikezwe umklomelo weNobel kabili:
- ukuthola incazelo yefomula ephelele yamakhemikhali nguPaul Carrer ngo-1937;
- ekutadisheni kwakhe ngemiphumela ezuzisayo ye-retinol ekubuyiselweni komsebenzi wokubuka nguGeorge Wald ngo-1967.
UVitamin A unamagama amaningi. Okudume kakhulu yi-retinol. Ungathola futhi okulandelayo: i-dehydroretinol, i-anticerophthalmic noma i-vitamin elwa namagciwane.
Izakhiwo zamakhemikhali nezomzimba
Bambalwa abantu, uma bebheka le fomula, abazokwazi ukuqonda ukwehluka kwayo nezakhiwo zayo. Ngakho-ke, sizohlaziya ngokuningiliziwe.
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I-vitamin A molecule iqukethe kuphela amakristalu, abhujiswa ukukhanya, umoya-mpilo, futhi nawo awuncibiliki kahle emanzini. Kepha ngaphansi kwethonya lezinto eziphilayo, ihlanganiswe ngempumelelo. Abakhiqizi, bazi le vithamini, bayikhipha ngendlela yamaphilisi aqukethe amafutha, futhi, njengomthetho, basebenzisa ingilazi emnyama njengokupakisha.
Kanye emzimbeni, i-retinol yehla yaba izingxenye ezimbili ezisebenzayo - i-retinal ne-retinoic acid, iningi lazo eligxile kwizicubu zesibindi. Kepha ezinso bancibilika khona manjalo, kushiya kuphela okuncane okucishe kube ngu-10% wengqikithi. Ngenxa yekhono lokuhlala emzimbeni, kuvela indawo ethile ebekiwe, esetshenziswa ngokufanele ngumuntu. Le ndawo kavithamini A ilusizo ngokukhethekile kubasubathi, ngoba yibo abajwayele ukwanda kokusetshenziswa kwamavithamini ngenxa yokuvivinya umzimba njalo.
Emithonjeni ehlukahlukene, izinhlobo ezimbili zikavithamini A zingena emzimbeni.Kusuka ekudleni okuvela ezilwaneni, sithola ngqo i-retinol uqobo (encibilikayo enamafutha), kanye nemithombo yamaseli anikezela ngemvelaphi yezitshalo ane-bio-soluble carotene ngendlela ye-alpha, beta ne-gamma carotenes. Kepha i-retinol ingahlanganiswa nayo ngaphansi kwesimo esisodwa - ukuthola umthamo wemisebe ye-ultraviolet, ngamanye amagama - ukuhamba elangeni. Ngaphandle kwalokhu, i-retinol ayakhiwa. Into enjalo yokuguqulwa iyadingeka empilweni yesikhumba.
Izinzuzo zikavithamini A
- Ijwayelekile imetabolism.
- Ibuyisa ikhava yezicubu exhumanisayo.
- Kuvuselela amaseli wezicubu ze-lipid namathambo.
- Iphethe izakhiwo ezilwa namagciwane nezokulwa namagciwane.
- Kuqinisa izakhiwo zemvelo zokuvikela amaseli.
- Ivimbela izifo zezitho ezibonakalayo.
- Ihlanganisa amaseli oketshezi oluhlangene.
- Isekela ibhalansi yamanzi nosawoti wesikhala se-intracellular.
- Inomphumela we-antitumor.
- Ubamba iqhaza synthesis amaprotheni kanye steroid.
- Ibeka phakathi isenzo se-radicals.
- Ithuthukisa umsebenzi wezocansi.
Amandla kaVitamin A okulungisa amangqamuzana alimele kubalulekile kuzo zonke izinhlobo zezicubu ezixhunyiwe. Le mpahla isetshenziswa kakhulu ezinkambisweni zezimonyo; i-carotenoids ilwa ngamandla nezinguquko ezihlobene nobudala esikhunjeni, ithuthukise ukwakheka kwezinwele nezinzipho.
4 izakhiwo ezibalulekile ze-retinol ezidingwa ngabasubathi:
- kusiza ukuqinisa amathambo nokuvimbela i-calcium leaching;
- kugcina ileveli eyanele yokuthambisa amalunga;
- iqhaza ekwakhiweni kabusha kwamangqamuzana omzimba we-cartilage;
- ubamba iqhaza ekwandeni kwezakhamzimba kumaseli we-capsule fluid ehlangene, ayivimbele ekumeni.
Izinga lansuku zonke
I-Retinol iyadingeka kithi sonke ngobuningi obanele. Itafula likhombisa isidingo samavithamini nsuku zonke kumaqembu ahlukene ngeminyaka.
Isigaba | Isilinganiso sansuku zonke esivumelekile | Umthamo omkhulu ovunyelwe |
Izingane ezingaphansi konyaka owodwa ubudala | 400 | 600 |
Izingane ezineminyaka engu-1 kuya kwengu-3 ubudala | 300 | 900 |
Izingane ezineminyaka engu-4 kuya kwengu-8 ubudala | 400 | 900 |
Izingane ezineminyaka engu-9 kuya kwengu-13 ubudala | 600 | 1700 |
Amadoda aneminyaka engu-14 | 900 | 2800-3000 |
Abesifazane abaneminyaka engu-14 ubudala | 700 | 2800 |
Ukhulelwe | 770 | 1300 |
Omama abancelisayo | 1300 | 3000 |
Abasubathi abaneminyaka engu-18 ubudala | 1500 | 3000 |
Emabhodleleni anezithasiselo eziphilayo ezisebenzayo, njengomthetho, indlela yokuphatha nokuqukethwe kwento esebenzayo ku-1 capsule noma isipuni sokulinganisa kuchazwa. Ngokuya ngemininingwane etafuleni, ngeke kube nzima ukubala uvithamini A wakho ojwayelekile.
Uyacelwa uqaphele ukuthi isidingo samavithamini kubasubathi siphezulu kakhulu kunabantu abakude nezemidlalo. Kulabo abavame ukuveza umzimba ngokuzikhandla okukhulu, kubalulekile ukukhumbula ukuthi ukudla okwenziwa nsuku zonke kwe-retinol ukugcina impilo yezakhi zesistimu yemisipha kufanele okungenani kube yi-1.5 mg, kepha kungeqi ku-3 mg ukuze kugwenywe ukweqisa ngokweqile (lokhu kukhombisa netafula elingenhla) ...
Okuqukethwe kwe-Retinol kumikhiqizo
Sesishilo ukuthi izinhlobo ezahlukene ze-retinol zivela emikhiqizweni yezitshalo neyezilwane. Sazisa imikhiqizo engu-TOP 15 enokuqukethwe okuphezulu kwe-retinol:
Igama lomkhiqizo | Inani levithamini A ngamagremu ayi-100 (iyunithi yokukala - μg) | % wemfuneko yansuku zonke |
Isibindi (inyama yenkomo) | 8367 | 840% |
Isibindi Se-Cod Esikheniwe | 4400 | 440% |
Ibhotela / uswidi - ibhotela | 450 / 650 | 45% / 63% |
Ibhotela elicibilikile | 670 | 67% |
Isikhuphasha senkukhu | 925 | 93% |
I-caviar emnyama / i-caviar ebomvu | 550 | 55% |
I-caviar ebomvu | 450 | 45% |
Ijusi lesanqante / isanqante | 2000 | 200% |
Ijusi lesanqante | 350 | 35% |
Iparsley | 950 | 95% |
I-red rowan | 1500 | 150% |
AmaChives / amalikhi | 330 / 333 | 30%/33% |
Ushizi onzima | 280 | 28% |
Ukhilimu omuncu | 260 | 26% |
Ithanga, upelepele omnandi | 250 | 25% |
Abasubathi abaningi bakhulisa ukudla ngakunye okungafaki njalo ukudla okuvela kulolu hlu. Ukusetshenziswa kwezithako ezikhethekile ze-retinol kuzosiza ukuhlangabezana nesidingo sikavithamini A. Ifakwe kahle kanye namaprotheni nama-amino acid.
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Ukuphikisana nokusetshenziswa kwe-retinol
Kubalulekile ukukhumbula ukuthi uvithamini A ahlali untula ngaso sonke isikhathi. Ngenxa yekhono layo lokuqongelela esibindini, ingaba semzimbeni ngobuningi obanele isikhathi eside. Ngokuvivinya umzimba okunamandla nezinguquko ezihlobene nobudala, idliwa kakhulu, kepha noma kunjalo, akunconywa ukudlula okujwayelekile kwansuku zonke.
Ukudlula ngokweqile kwe-Retinol kungaholela emiphumeleni elandelayo:
- izinguquko zesifo esibindi;
- ukudakwa kwezinso;
- ukuphuzi kolwelwesi lwamafinyila kanye nesikhumba;
- umfutho wegazi ophakeme ngaphakathi.