Okuqukethwe
Igama lomhlaba jikelele -, njengesengezo sokudla esibizwa nangokuthi I-Retinol.
Ivithamini encibilika kumafutha, isakhi esibalulekile sokukhula okunempilo, ukwakheka kwezicubu zamathambo namazinyo, kanye nesakhiwo samaseli. Kubaluleke kakhulu ekuboneni ebusuku, kuyadingeka ukuvikela ezifweni zezicubu zokuphefumula, ukugaya ukudla kanye namapheshana omchamo. Unomthwalo wemfanelo wobuhle nobusha besikhumba, impilo yezinwele nezinzipho, i-acuity ebonakalayo. I-Vitamin A idonswa emzimbeni ngendlela ye-Retinol, etholakala esibindini, emafutheni ezinhlanzi, e-egg yolk, imikhiqizo yobisi futhi yengezwe kumajarini. I-Carotene, eguqulwa ibe yi-Retinol emzimbeni, itholakala emifino nezithelo eziningi.
Umlando wokutholakala
Izidingo zokuqala zokutholakala kukaVitamin A kanye nemiphumela yokushoda kwayo kwavela emuva ngonyaka we-1819, lapho udokotela womzimba waseFrance kanye nesazi sokusebenza kwengqondo uMagendie eqaphela ukuthi izinja ezingondlekile kahle kungenzeka zithole izilonda zamakhaza futhi zibe nezinga eliphakeme lokufa.
Ngo-1912, isazi samakhemikhali saseBrithani uFrederick Gowland Hopkins sathola izinto ezingaziwa obisini ezazingafani namafutha, ama-carbohydrate noma amaprotheni. Ngokuhlolisisa, kwavela ukuthi bakhuthaza ukukhula kwamagundane elebhu. Ngokuthola kwakhe, uHopkins wathola umklomelo weNobel ngo-1929. Ngo-1917, u-Elmer McCollum, uLafayette Mendel, noThomas Burr Osborne nabo babona izinto ezifanayo lapho befunda ngendima yamafutha adlayo. Ngo-1918, lezi “zinto ezingeziwe” kwatholakala ukuthi zincibilika emafutheni, kwathi ngo-1920 ekugcineni zabizwa ngoVitamin A.
Uvithamini A ukudla okunothile
Kuboniswe ukutholakala okulinganiselwa ku-100 g womkhiqizo
| + Ukudla okuningi okungu-16 okunothe ku-vitamin A (inani lama-μg ku-100 g womkhiqizo likhonjisiwe): | |||||||
| Basil | 264 | Iqanda lezigwaca | 156 | i-Mango | 54 | Utamatisi | 42 |
| I-mackerel eluhlaza | 218 | Cream | 124 | I-Fennel, impande | 48 | ama-prunes | 39 |
| I-Rosehip, izithelo | 217 | Ibhilikosi | 96 | Upelepele | 48 | I-broccoli | 31 |
| Iqanda eliluhlaza | 160 | isitshalo esihlobene no-anyanisi | 83 | ubhamubhamu | 46 | izimbaza | 8 |
Imfuneko yansuku zonke yevithamini A
Izincomo zokutholwa kukavithamini A nsuku zonke zisuselwa kunani elidingekayo lokunikezela ngeRetinol izinyanga ezimbalwa ngaphambi kwesikhathi. Lesi siqiwi sisekela ukusebenza komzimba okujwayelekile futhi siqinisekisa ukusebenza okunempilo kohlelo lokuzala, ukuzivikela komzimba, umbono nokusebenza kofuzo.
Ngo-1993, i-European Scientific Committee on Nutrition yashicilela imininingwane ngokudla okunconywayo kukavithamini A:
| Ubudala | Abesilisa (mcg ngosuku) | Abesifazane (mcg ngosuku) |
| 6-12 izinyanga | 350 | 350 |
| iminyaka 1-3 | 400 | 400 |
| iminyaka 4-6 | 400 | 400 |
| iminyaka 7-10 | 500 | 500 |
| iminyaka 11-14 | 600 | 600 |
| iminyaka 15-17 | 700 | 600 |
| Iminyaka engu-18 nangaphezulu | 700 | 600 |
| ukukhulelwa | - | 700 |
| Isisu | - | 950 |
Amakomidi amaningi ase-Europe okondla, njengeGerman Nutrition Society (DGE), ancoma u-0,8 mg (800 mcg) kavithamini A (Retinol) ngosuku kwabesifazane kanye no-1 mg (1000 mcg) wamadoda. Njengoba uvithamini A edlala indima enkulu ekukhuleni okujwayelekile kombungu nasenganeni esanda kuzalwa, abesifazane abakhulelwe bayelulekwa ukuthi bathathe u-1,1 mg kavithamini A kusukela enyangeni yesi-4 yokukhulelwa. Abesifazane abancelisayo kufanele bathole u-1,5 mg kavithamini A ngosuku.
Ngo-2015, i-European Food Safety Authority (i-EFSA) yasungula ukuthi ukudla ivithamini A nsuku zonke kufanele kube ngu-750 mcg kwabesilisa, 650 mcg kwabesifazane, kanye nezinsana nezingane ezingama-250 kuya ku-750 mcg kavithamini A ngosuku, kucatshangelwa iminyaka . … Ngesikhathi sokukhulelwa kanye ne-lactation, inani elengeziwe levithamini okufanele lingene emzimbeni ngenxa yokuqoqwa kweRetinol ezicutshini zombungu nomama, kanye nokufakwa kweRetinol obisini lwebele, kuboniswe inani lama-700 kanye 1,300 mcg ngosuku, ngokulandelana.
Ngo-2001, i-American Food and Nutrition Board nayo yasetha ukudla okunconywayo kukavithamini A:
| Ubudala | Abesilisa (mcg ngosuku) | Abesifazane (mcg ngosuku) |
| 0-6 izinyanga | 400 | 400 |
| 7-12 izinyanga | 500 | 500 |
| iminyaka 1-3 | 300 | 300 |
| iminyaka 4-8 | 400 | 400 |
| iminyaka 9-13 | 600 | 600 |
| iminyaka 14-18 | 900 | 700 |
| Iminyaka engu-19 nangaphezulu | 900 | 700 |
| Ukukhulelwa (iminyaka engu-18 nangaphansi) | - | 750 |
| Ukukhulelwa (iminyaka engu-19 nangaphezulu) | - | 770 |
| Ukuncelisa ibele (iminyaka engu-18 nangaphansi) | - | 1200 |
| Ukuncelisa ibele (iminyaka engu-19 nangaphezulu) | - | 1300 |
Njengoba sikwazi ukubona, yize inani lihluka ngokuya ngezinhlangano ezahlukahlukene, isilinganiso sokudla kwansuku zonke sikavithamini A sihlala ezingeni elifanayo.
Isidingo sikavithamini A siyanda nge:
- 1 ukuzuza kwesisindo;
- 2 umsebenzi okhandlayo;
- 3 ukusebenza ngokushintshana ebusuku;
- 4 ukubamba iqhaza emincintiswaneni yezemidlalo;
- Izimo ezi-5 ezicindezelayo;
- Umsebenzi we-6 ezimeni zokukhanya okungafanele;
- Ukukhishwa kwamehlo okwengeziwe okungama-7 kubaqaphi;
- 8 ukukhulelwa, ukuncelisa ibele;
- Izinkinga eziyi-9 ngomgudu wamathumbu;
- I-10 ARVI.
Izakhiwo zomzimba nezamakhemikhali
I-Vitamin A iyivithamini encibilikayo enamafutha eqembu lama-molecule anesakhiwo esifanayo - i-retinoids - futhi itholakala ngezindlela zamakhemikhali eziningana: i-aldehydes (retinal), i-alcohol (i-Retinol), ne-asidi (i-retinoic acid). Emikhiqizweni yezilwane, uhlobo oluvame kakhulu lwevithamini A i-ester, ngokuyinhloko i-retinyl palmitate, ehlanganiswa ku-Retinol emathunjini amancane. Ama-provitamins - ama-biochemical precursors we-vitamin A - akhona ekudleni kwezitshalo, ayingxenye yeqembu le-carotenoid. Ama-carotenoids ama-pigment emvelo avela ngokwemvelo kuma-chromoplast ezitshalo. Ngaphansi kwe-10% ye-carotenoid engama-563 eyaziwa isayensi ingahlanganiswa ibe uvithamini A emzimbeni.
UVitamin A uvithamini oncibilika njengamafutha. Leli yigama leqembu lamavithamini, lokwenziwa kwalo lapho umzimba udinga khona ukudla kwamafutha adliwayo, owoyela noma we-lipids. Lokhu kufaka phakathi, isibonelo, ukupheka ,,,, ukwatapheya.
Izithako zokudla i-Vitamin A zivame ukutholakala kumaphilisi agcwele uwoyela ukuze uvithamini amuncwe ngokuphelele ngumzimba. Abantu abangawadli ngokwanele amanoni adliwayo maningi amathuba okuthi bangabi namavithamini ancibilika ngamafutha. Izinkinga ezifanayo zingenzeka kubantu abanamafutha amuncu. Ngenhlanhla, amavithamini ancibilikayo anamafutha atholakala ngokwemvelo atholakala ekudleni okuqukethe amafutha. Ngakho-ke, ngokudla okwanele, ukuntuleka kwamavithamini anjalo akuvamile.
Ukuze uvithamini A noma i-carotene ingene egazini emathunjini amancane, kuyadingeka ukuthi, njengamanye amavithamini ancibilika amafutha, ahlangane nenyongo. Uma ukudla ngalesi sikhathi kuqukethe amafutha amancane, khona-ke i-bile encane ifihliwe, okuholela ekusetshenzisweni kwe-malabsorption kanye nokulahlekelwa ngamaphesenti angama-90 we-carotene novithamini A endle.
Cishe ama-30% we-beta-carotene amuncwa ekudleni kwezitshalo, cishe isigamu se-beta-carotene siguqulwa sibe nguvithamini A. Kusuka ku-6 mg we-carotene emzimbeni, kwakhiwa u-1 mg kavithamini A, ngakho-ke ukuguqulwa kwenani ye-carotene esilinganisweni sevithamini A ngu-1: 6.
Sincoma ukuthi uzijwayeze nge-assortment ye-Vitamin A enkulu kunazo zonke emhlabeni. Kunemikhiqizo engaphezu kuka-30,000 ehambisana nemvelo, izintengo ezikhangayo nokukhushulwa okuvamile, okungaguquki Isaphulelo esingu-5% esinekhodi yephromo CGD4899, ukuthunyelwa kwamahhala emhlabeni wonke kuyatholakala.
Izici ezizuzisayo zikavithamini A
UVitamin A unemisebenzi eminingana emzimbeni. Okudume kakhulu umphumela wayo kumbono. I-Retinyl ester iyiswa e-retina, engaphakathi kweso, lapho iguqulwa ibe yinto ebizwa nge-11-cis-retinal. Ngaphezu kwalokho, i-11-cis-retinal iphelela ezintanjeni (enye yama-photoreceptors), lapho ihlangana khona neprotheyini ye-opsin futhi yakhe i-pigment ebonakalayo "i-rhodopsin". Izinduku eziqukethe iRhodopsin zingathola ngisho nokukhanya okuncane kakhulu, kuzenze zibalulekile ekubukeni ebusuku. Ukumuncwa kwe-photon yokukhanya kukhuthaza ukuguqulwa kwe-11-cis-retinal ibuyele emuva kuwo wonke ama-trans retinal futhi kuholele ekukhishweni kwayo kuprotheni. Lokhu kudala uchungechunge lwezehlakalo eziholela ekwakhiweni kwesiginali ye-electrochemical kuya emthanjeni we-optic, ocutshungulwa futhi utolikwe ubuchopho. Ukuntuleka kweRetinol okutholakala kwi-retina kuholela ekuthini kungahambelani kahle nobumnyama obaziwa ngokuthi ukungaboni ebusuku.
Vitamin A ngesimo se-retinoic acid idlala indima ebalulekile ekulawulweni kwenkulumo yezakhi zofuzo. Lapho i-Retinol isimunce iseli, ingaxhunyaniswa ne-retinal, ehlanganiswe ne-retinoic acid. I-Retinoic acid iyimolekyuli enamandla kakhulu ebopha kuma-receptors ahlukahlukene enuzi ukuqala noma ukuvimbela ukubonakaliswa kofuzo. Ngokulawulwa kokuvezwa kwezakhi zofuzo ezithile, i-retinoic acid idlala indima ebalulekile ekuhlukanisweni kwamaseli, omunye wemisebenzi ebaluleke kakhulu yomzimba.
I-Vitamin A iyadingeka ekusebenzeni okujwayelekile kwesistimu yomzimba. I-Retinol nama-metabolite ayo ayadingeka ukugcina ubuqotho nokusebenza kwamaseli esikhumba kanye nolwelwesi lwamafinyila (izinhlelo zokuphefumula, zokugaya ukudla nezokuchama). Lezi zicubu zisebenza njengesithiyo futhi ziyindlela yokuqala yokuzivikela ezifweni. UVitamin A udlala indima enkulu ekwakhiweni nasekuhlukanisweni kwamangqamuzana amhlophe egazi, ama-lymphocyte, okuyizinto ezibalulekile ekuphenduleni amasosha omzimba.
UVitamin A ubalulekile ekukhuleni kombungu, uthatha ingxenye ngqo ekukhuleni kwezitho, ukwakheka kwenhliziyo, amehlo nezindlebe zombungu. Ngaphezu kwalokho, i-retinoic acid ithinta ukubonakaliswa kohlobo lofuzo lwe-hormone yokukhula. Kokubili ukungabi nalutho novithamini A okweqile kungadala ukukhubazeka kokuzalwa.
UVitamin A usetshenziselwa ukukhula okujwayelekile kwamaseli ezinhlayiya abe ngamaseli abomvu egazi. Ngaphezu kwalokho, uvithamini A ubonakala enza ngcono ukuhlanganiswa kwensimbi kusuka ezinqolobaneni ezisemzimbeni, eyiqondisa esitokisini segazi esibomvu esikhulayo. Lapho, i-iron ifakiwe ku-hemoglobin - othwala umoya-mpilo kuma-erythrocyte. I-Vitamin A metabolism kukholakala ukuthi iyasebenzisana futhi nangezindlela eziningana. Ukushoda kwe-Zinc kungaholela ekwehleni kwenani le-Retinol ethuthwayo, ukwehla kokukhishwa kwe-Retinol esibindi nokuncipha kokuguqulwa kwe-Retinol kuya ku-retina. Izithasiselo zika Vitamin A zinomthelela omuhle ekushodweni yensimbi (i-anemia) futhi zithuthukisa ukumuncwa kwensimbi ezinganeni nakwabesifazane abakhulelwe. Ukuhlanganiswa kukavithamini A nensimbi kubonakala kuphulukisa kahle kakhulu kunensimbi yokwengeza noma uvithamini A.
Ucwaningo lwakamuva lukhombisile ukuthi uvithamini A, i-carotenoids, ne-provitamin A carotenoids zingasebenza ekuvimbeleni ukukhula kwesifo senhliziyo. Umsebenzi we-antioxidant ka-vitamin A kanye ne-carotenoids unikezwa ngochungechunge lwe-hydrophobic yama-polyene units, angaqeda i-singlet oxygen (i-oxygen yamangqamuzana ngomsebenzi ophakeme), anciphise ama-radicals we-thiyl, futhi aqinise ama-radicals e-peroxyl. Ngamafuphi, uma uchungechunge lwe-polyene lude, kukhuphuka ukuzinza kwe-peroxyl radical. Ngenxa yokwakheka kwawo, uvithamini A kanye ne-carotenoids zingafakwa i-oxidized lapho ingcindezi ye-O2 yanda futhi ngenxa yalokho ingama-antioxidants asebenza kakhulu ekucindezelekeni komoya-mpilo okuyizici zamazinga womzimba atholakala ezicutshini. Sekukonke, ubufakazi bokusabalala kwezifo busikisela ukuthi uvithamini A kanye ne-carotenoids yizinto ezibalulekile ekudleni ekunciphiseni isifo senhliziyo.
I-European Food Safety Authority (i-EFSA), enikezela ngezeluleko zesayensi kubenzi bezinqubomgomo, iqinisekisile ukuthi izinzuzo zezempilo ezilandelayo zibonwe ngokusetshenziswa kukavithamini A:
- ukuhlukaniswa kweseli okuvamile;
- ukuthuthukiswa okuvamile nokusebenza kwamasosha omzimba;
- ukugcina isimo esijwayelekile sesikhumba kanye nolwelwesi lwamafinyila;
- ukugcinwa kombono;
- i-metabolism ejwayelekile yensimbi.
UVitamin A unokuhambisana okuphezulu namavithamini C no-E kanye namaminerali insimbi ne-zinc. Amavithamini C no-E avikela uvithamini A ekungenisweni yi-oxidation. Vitamin E kwandisa ukumuncwa uvithamini A, kodwa kuphela ezimweni lapho uvithamini E kudliwe ngamanani amancane. Okuqukethwe u-vitamin E okuphezulu ekudleni, nakho, kuphazamisa ukumuncwa kukavithamini A. Zinc kusiza ukumuncwa kukavithamini A ngokubamba iqhaza ekuguqukeni kwawo kube yiRetinol. IVitamin A ithuthukisa ukumuncwa kwensimbi futhi ithinta ukusetshenziswa kwenqolobane yensimbi ekhona esibindi.
I-Vitamin A nayo isebenza kahle ngamavithamini D no-K2, i-magnesium, namafutha adlayo. Amavithamini A, D no-K2 asebenza ngokubambisana ukusekela impilo yomzimba, ukukhuthaza ukukhula okwanele, ukugcina impilo yamathambo namazinyo, nokuvikela izicubu ezithambile ekubalweni. I-Magnesium ibalulekile ekukhiqizweni kwawo wonke amaprotheni, kufaka phakathi lawo asebenzisana namavithamini A no-D. Amaprotheni amaningi abandakanyeka ekusetshenzisweni komzimba kavithamini A kanye nama-receptors wawo womabili amavithamini A no-D asebenza kahle kuphela lapho kukhona i-zinc.
Amavithamini A no-D nawo asebenza ndawonye ukulawula ukukhiqizwa kwamaprotheni athile ancike kumavithamini. Lapho nje uvithamini K esebenze lawa maprotheni, asiza ukufaka amaminerali emathanjeni namazinyo, avikele imithambo nezinye izicubu ezithambile ekubalweni okungajwayelekile, futhi avikele ekufeni kweseli.
Ukudla kwe-Vitamin A kusetshenziswe kangcono ngokudla okunamafutha "anempilo". Isibonelo, isipinashi, esinevithamini A kanye ne-lutein, sinconywa ukuba sihlanganiswe naso. Okufanayo kuya ku-ulethisi kanye nezaqathi, ezihamba kahle nama-avocados kumasaladi. Njengomthetho, imikhiqizo yezilwane ecebile nge-vitamin A kakade iqukethe inani elithile lamafutha, anele ukumuncwa kwayo okuvamile. Ngokuqondene nemifino nezithelo, kunconywa ukwengeza inani elincane lamafutha emifino esaladini noma ijusi elisanda kufakwa - ngale ndlela sizoqiniseka ukuthi umzimba uzothola i-vitamin edingekayo ngokugcwele.
Kumele kuqashelwe ukuthi umthombo ongcono kakhulu we-vitamin A ikakhulukazi, kanye nezinye izinto ezizuzisayo, ukudla okulinganiselayo kanye nemikhiqizo yemvelo, kunokuba izithako zokudla. Ukusebenzisa amavithamini ngendlela yokwelapha, kulula kakhulu ukwenza iphutha ngomthamo futhi uthole okungaphezu kokudinga umzimba. Ukuchichima ngokweqile kwevithamini noma imineral eyodwa emzimbeni kungaba nemiphumela emibi kakhulu. Ingozi yokuthuthukisa izifo ze-oncological ingase ikhule, isimo somzimba jikelele siwohloka, i-metabolism kanye nomsebenzi wezinhlelo zezitho kuyaphazamiseka. Ngakho-ke, ukusetshenziswa kwamavithamini ezibhebheni kufanele kwenziwe kuphela uma kunesidingo nangemva kokubonisana nodokotela.
Isicelo kwezokwelapha
Ukusetshenziswa kwenani elikhulu likavithamini A kunqunywe ezimweni ezilandelayo:
- ngenxa yokushoda kukavithamini A, okungenzeka kubantu abanamaprotheni, i-thyroid gland, umkhuhlane, isifo sesibindi, i-cystic fibrosis, noma isifo esivela ku-abelatipoproteinemia.
- ngomdlavuza webele. Abesifazane be-premenopausal abanomlando womndeni womdlavuza webele abadla amazinga aphezulu kavithamini A ekudleni kwabo kucatshangwa ukuthi banciphisa ingozi yokuba nomdlavuza webele. Akwaziwa ukuthi ukwengeza i-vitamin A kunomphumela ofanayo yini.
- … Ucwaningo lukhombisa ukuthi ukudla kakhulu uvithamini A ekudleni kuholela engcupheni encishisiwe yokuhlaselwa ngulwelwelwe.
- ngesifo sohudo esibangelwa. Ukuthatha uvithamini A kanye nemithi ejwayelekile kubonakala kunciphisa ingozi yokufa kuhudo ezinganeni ezinegciwane lesandulela ngculaza ezinokushoda kukavithamini A.
- … Ukuthatha uvithamini A ngomlomo kunciphisa izimpawu zikamalaleveva ezinganeni ezingaphansi kweminyaka emithathu ubudala ezindaweni lapho umalaleveva uvame khona.
- … Ukuthatha uvithamini A ngomlomo kunciphisa ubungozi bezinkinga noma ukufa okubangelwa isimungumungwane ezinganeni ezinesimungumungwane ezingenawo uvithamini A.
- ngezilonda ezingaphambi komlomo (i-leukoplakia yomlomo). Ucwaningo lukhombisa ukuthi ukuthatha uvithamini A kungasiza ekwelapheni izilonda zangaphambi komlomo.
- lapho ululama ekuhlinzweni iso kwe-laser. Ukuthatha i-vitamin A ngomlomo kanye ne-vitamin E kuthuthukisa ukwelashwa ngemuva kokuhlinzwa kwamehlo laser.
- nezinkinga ngemuva kokukhulelwa. Ukuthatha uvithamini A kunciphisa ubungozi bohudo nomkhuhlane ngemuva kokukhulelwa kwabesifazane abangondlekile.
- nezinkinga ngesikhathi sokukhulelwa. Ukuthatha i-vitamin A ngomlomo kunciphisa ingozi yokufa nobumpumputhe ebusuku ngesikhathi sokukhulelwa kwabesifazane abangondlekile.
- yezifo zamehlo ezithinta i-retina (i-retinitis pigmentosa). Ucwaningo lukhombisa ukuthi ukuthatha uvithamini A kunganciphisa ukukhula kwezifo zamehlo ezilimaza i-retina.
Uhlobo lwe-vitamin A lwezemithi lungahluka. Kwezokwelapha, itholakala ngesimo samaphilisi, amaconsi okuphathwa ngomlomo, amaconsi okuphathwa ngomlomo ngendlela enamafutha, amaphilisi, isisombululo esinamafutha sokuphathwa kwemisipha, isisombululo esinamafutha sokuphathwa ngomlomo, ngesimo samaphilisi agqunywe ngefilimu. U-Vitamin A uthathwa nge-prophylaxis nangezinjongo zokwelapha, njengomthetho, imizuzu eyi-10-15 ngemuva kokudla. Izixazululo zika-oyela zithathwa uma kwenzeka i-malabsorption emgodini wamathumbu noma isifo esibi. Ezimweni lapho ukwelashwa kwesikhathi eside kudingekile, isixazululo somjovo we-intramuscular sihlangene namaphilisi. Kwezemithi, uvithamini A uvame ukucashunwa kuzinyunithi zomhlaba Ngokushoda kukavithamini okulingene ukuya kokulingene, abantu abadala babekelwa amayunithi angama-33 ayizinkulungwane zomhlaba ngosuku; nge-hemeralopia, i-xerophthalmia - i-IU / ngosuku eyizinkulungwane ezingama-50-100; izingane - 1-5 izinkulungwane IU / ngosuku, kuye ngeminyaka; ngezifo zesikhumba kubantu abadala - izinkulungwane ezingama-50-100 ze-IU / ngosuku; izingane - 5-20 izinkulungwane IU / ngosuku.
Imithi yendabuko yeluleka ukusebenzisa uvithamini A njengekhambi lesikhumba esintekenteke nesingenampilo. Ngenxa yalokhu, kunconywa ukusebenzisa uwoyela wezinhlanzi, isibindi, uwoyela namaqanda, kanye nemifino ecebile ngovithamini A - ithanga, ibhilikosi, izaqathe. Ijusi lesanqante elisanda kufakwa ngokufaka ukhilimu noma uwoyela wemifino yikhambi elihle lokuntuleka. Elinye ikhambi lesintu lokuthola i-vithamini lithathwa njenge-decoction yezilimo eziyizigaxa ze-potbelly tuber - isetshenziswa njenge-tonic, restorative and antirheumatic agent. Imbewu yefilakisi nayo ibhekwa njengomthombo obalulekile kavithamini A, kanye nezinye izinto eziwusizo, ezisetshenziswa ngaphakathi nanjengengxenye yamamaski angaphandle, amafutha okugcoba kanye nama-decoctions. Ngokusho kweminye imibiko, inani eliphakeme levithamini A liqukethwe eziqongweni zezaqathe, ngisho nangaphezu kwesithelo uqobo. Ingasetshenziselwa ukupheka, kanye nokwenza i-decoction, esetshenziswa ngaphakathi njengenkambo yenyanga.
Ucwaningo Lwakamuva Lwesayensi kuVithamini A:
Abaphenyi e-Case Western Reserve University School of Medicine bathole ukuthi umzimba ongalawulwa wevithamini A esiswini ungadala ukuvuvukala okuyingozi. Ukutholwa kusungula ukuxhumana phakathi kokwakheka kokudla kanye nezifo zokuvuvukala - kanye ne-sore gut syndrome.
Abaphenyi bathole iphuzu legatsha emzileni we-vitamin A we-metabolic oncike kuphrotheni ethile ebizwa nge-ISX. Ukuqala kwendlela yi-beta-carotene - into enomsoco kakhulu enombala, ngenxa yokuthi umbala wombhatata namanqathe wakhiwa kanjani. I-beta-carotene iguqulwa ibe yi-vitamin A emgudwini wokugaya ukudla. Ukusuka lapho, ingxenye enkulu kavithamini A iyiswa kwezinye izicubu, iqinisekise umbono omuhle neminye imisebenzi ebalulekile. Ocwaningweni lwamagundane ayesuswe yi-ISX, ososayensi baqaphela ukuthi iphrotheni lisiza umzimba ukulinganisa le nqubo. Amaprotheni asiza ithumbu elincane ukuthi linqume ukuthi Kudingeka isikhathi esingakanani i-beta-carotene ukuhlangabezana nesidingo somzimba sevithamini A. Amaseli omzimba ancike kule ndlela yokulawula ukuphendula kahle ekudleni okungena emathunjini amancane. Lokhu kunikeza isithiyo esisebenzayo ekulweni nezinsongo ezihlobene nokudla. Abaphenyi bathole ukuthi lapho i-ISX ingekho, amaseli omzimba asemgudwini wokugaya ukudla aphendula kakhulu ekudleni okugcwele i-beta-carotene. Imiphumela yabo ifakazela ukuthi i-ISX iyisixhumanisi esiyinhloko phakathi kwalokho esikudlayo nokuzivikela emathunjini. Ososayensi baphethe ngokuthi ukukhipha iphrotheni ye-ISX kusheshisa ukubonakaliswa kofuzo okuguqula i-beta carotene ibe yi-vitamin A 200. Ngenxa yalokhu, amagundane asuswe yi-ISX athola i-vitamin A eyeqile futhi aqala ukuyiguqula yaba yi-retinoic acid, i-molecule elawula ukusebenza kwezakhi zofuzo eziningi, kufaka phakathi lezo ezakha ukuzivikela. Lokhu kubangele ukuvuvukala okwenziwe endaweni njengamaseli omzimba agcwalisa indawo emathunjini phakathi kwesisu nekholoni futhi aqala ukwanda. Lokhu kuvuvukala okukhulu kwasakazeka kumanyikwe futhi kwabangela ukungasebenzi komzimba kumagundane.
Ucwaningo lwakamuva lukhombisa ukuthi uvithamini A wandisa umsebenzi wama-insulin-cell akhiqiza i-insulin. Ososayensi bathole ukuthi amangqamuzana e-beta akhiqiza i-insulin anenani eliphakeme lama-receptors ebusweni bawo azwela uvithamini A. Abaphenyi bakholelwa ukuthi lokhu kungenxa yokuthi uvithamini A ubamba iqhaza elibalulekile ekukhuleni kwamaseli e-beta ezigabeni zokuqala zempilo. , kanye nokwenza okulungile nokusebenza ngesikhathi sempilo yonke, ikakhulukazi phakathi kwezimo ze-pathophysiological - okungukuthi, ngezifo ezithile zokuvuvukala.
Ukufunda ukubaluleka kukavithamini A oshukela, abacwaningi basebenze namaseli e-insulin avela kumagundane, abantu abaphilile, nabantu abanesifo sikashukela sohlobo lwe-2. Ososayensi bavimbe kancane ama-receptors futhi banikeza iziguli ushukela. Babona ukuthi amandla amaseli okukhipha i-insulin ayesewohloka. Umkhuba ofanayo ungabonwa lapho uqhathanisa amaseli e-insulin avela kubaxhasi nohlobo 2 lwesifo sikashukela. Amaseli eziguli ezinesifo sikashukela sohlobo 2 ayengakwazi ukukhiqiza i-insulini uma kuqhathaniswa namaseli avela kubantu abangenaso isifo sikashukela. Ososayensi bathole nokuthi ukumelana kwamaseli we-beta nokuvuvukala kuncishisiwe uma kungekho vithamini A. Uma uvithamini A engekho, amaseli ayafa. Lolu cwaningo lungahle lube nemithelela kwezinye izinhlobo zohlobo lwesifo sikashukela esingu-1, lapho amaseli e-beta engakhuli kahle ezigabeni zokuqala zempilo. “Njengoba kuye kwacaca ngemuva kokufunda nezilwane, amagundane asanda kuzalwa adinga uvithamini A ukuze kuthuthukiswe ngokugcwele amaseli awo e-beta. Siyaqiniseka ukuthi kuyafana nakubantu. Izingane zidinga ukuthola uvithamini A owanele ekudleni kwazo, ”kusho u-Albert Salehi, oyi-Senior Research Fellow esikhungweni sikashukela eLund University eSweden.
Ososayensi e-University of Lund eSweden bathole umphumela obengakahlolwa ngaphambili kavithamini A ekukhuleni kombungu womuntu. Ucwaningo lwabo lukhombisa ukuthi uvithamini A unomthelela ekwakhekeni kwamaseli egazi. I-molecule esayinayo eyaziwa ngokuthi i-retinoic acid isuselwa ku-vitamin A okusiza ukunquma ukuthi izinhlobo ezahlukahlukene zezicubu zizokwakhiwa kanjani embungwini okhulayo.
Ucwaningo olungakaze lubonwe elebhu elenziwa nguSolwazi Niels-Bjarn Woods eLund Stam Cell Centre eSweden luveze umphumela we-retinoic acid ekwakheni amangqamuzana abomvu egazi, amangqamuzana amhlophe egazi kanye nama-platelet avela kuma-stem cell. Elebhu, amaseli ama-stem athonywe ama-molecule athile okusayina, aguqulwa abe ngamaseli we-hematopoietic. Ososayensi baqaphele ukuthi amazinga aphezulu e-retinoic acid anciphisa ngokushesha inani lamaseli egazi akhiqizwayo. Ukwehla kwe-retinoic acid, kukhuphule ukukhiqizwa kwamaseli egazi ngo-300%. Ngaphandle kokuthi i-vitamin A iyadingeka enkambweni ejwayelekile yokukhulelwa, kutholakele ukuthi uvithamini A owedlulele ulimaza umbungu, wethula ubungozi bokumiswa kabi noma ukuqedwa kokukhulelwa. Ngenxa yalokhu, abesifazane abakhulelwe bayelulekwa ngokuqinile ukuthi balawule ukusetshenziswa kokudla okuqukethe inani elikhulu likavithamini A ngendlela yama-retinoids, njengesibonelo, isibindi. “Imiphumela yocwaningo lwethu ikhombisa ukuthi inani elikhulu likavithamini A linomthelela omubi kwi-hematopoiesis. Lokhu kuphakamisa ukuthi abesifazane abakhulelwe kufanele futhi bagweme ukudla ngokweqile uvithamini A, ”kusho uNiels-Bjarn Woods.
Uvithamini A ku-cosmetology
Ingesinye sezithako eziyinhloko zesikhumba esinempilo nesinethoni. Lapho uthola inani elanele lamavithamini, ungakhohlwa ngezinkinga ezinjengokukhathala kwesikhumba, izindawo zeminyaka, induna, ukoma.
I-Vitamin A ngendlela ehlanzekile, egxilile ingatholakala kalula kuma-pharmacy, ngendlela yama-capsules, izixazululo zamafutha kanye nama-ampoules. Kuyafaneleka ukukhumbula ukuthi lokhu kuyingxenye esebenzayo, ngakho-ke, kufanele isetshenziswe ngokuqapha, futhi mhlawumbe ngemva kweminyaka engama-35. I-cosmetologists yeluleka ukwenza imaski equkethe i-vitamin A ngesikhathi esibandayo kanye ngenyanga. Uma kukhona ukuphikisana nokusetshenziswa kwe-vitamin A ekhemisi ekwakhiweni kwemaski, ungayifaka esikhundleni semikhiqizo yemvelo ecebile kule vithamini - i-kalina, i-parsley, isipinashi, izikhupha zamaqanda, imikhiqizo yobisi, ithanga, izaqathe, amafutha ezinhlanzi, ulwelwe.
Kunezindlela eziningi zokupheka zamamaski ezine-vitamin A. Zivame ukufaka izinto eziqukethe amafutha - ukhilimu omuncu omuncu, uwoyela we-burdock. I-Vitamin A (isixazululo samafutha ne-Retinol acetate) isebenza kahle ngejusi le-aloe, i-oatmeal noju. Ukuqeda imibimbi nokulimaza ngaphansi kwamehlo, ungasebenzisa ingxube kavithamini A nanoma yimuphi uwoyela wemifino, noma isidakamizwa i-Aevit, esivele iqukethe kokubili uvithamini A novithamini E. Ikhambi elihle lokuvikela nokwelapha induna imaski umhlabathi, uvithamini A ku-ampoule noma inani elincane lamafutha e-zinc, lisetshenziswa izikhathi ezimbili ngenyanga. Lapho kukhona ukungezwani komzimba, izilonda ezivulekile nokulimala esikhunjeni, noma yisiphi isifo saso, kufanele uyeke ukusebenzisa imaski enjalo.
UVitamin A ubuye alungele impilo yezipikili lapho exutshwe nezinye izithako. Isibonelo, ungalungisa imaski yesandla enamavithamini angu-A, B, no-D, ukhilimu wesandla oily, ujusi kalamula, nethonsi le-iodine. Le nhlanganisela kufanele isetshenziswe esikhumbeni sezandla nakumapuleti ezipikili, ukubhucungwa imizuzu engu-20 bese ushiya ukumunca. Ukwenza le nqubo njalo kuzothuthukisa isimo sezinzipho zakho nezandla zakho.
Imiphumela kavithamini A empilweni yezinwele nobuhle akufanele ibukelwe phansi. Ingangezelwa kuma-shampoo (ngaphambi nje kwenqubo ngayinye, ukuze kugwenywe uketshezi lwento lapho ingezwa kuyo yonke iphakethe le-shampoo), kumaski - ukwandisa ukukhanya, ukuthamba kwamandla ezinwele. Njengakumaski obuso, i-vitamin A inconywa ukuthi ihlanganiswe nezinye izithako - uvithamini E, uwoyela ohlukahlukene, ama-decoctions (i-chamomile, i-horsetail), (ukuthamba), lwesinaphi noma upelepele (ukusheshisa ukukhula kwezinwele). Lezi zimali kufanele zisetshenziswe ngokuqapha kulabo abaguliswa i-vitamin A ekhemisi kanye nalabo abanezinwele ezithambekele kokuqukethwe okunamafutha amaningi.
Uvithamini A emfuyweni, esitshalweni nasembonini
Kutholakala otshanini obuluhlaza, i-alfalfa kanye namanye amafutha ezinhlanzi, i-vitamin A, eyaziwa nangokuthi i-Retinol, ingenye yezakhi zomzimba ezidingekayo empilweni yezinkukhu. Ukushoda kukavithamini A kuholela emapulazini amabi kanye nobuthakathaka, izinkinga zamehlo nezomlomo, kuze kufike lapho kulimala khona. Esinye isici esibalulekile ekukhiqizweni ukuthi ukuntuleka kukavithamini A kunganciphisa ukukhula.
Uvithamini A unempilo eshalofini elifushane uma kuqhathaniswa, ngenxa yalokho, ukudla okomile okugcinwe isikhathi eside kungahle kungabi novithamini A. owanele Ngemuva kokugula noma kwengcindezi, amasosha omzimba ale nyoni abuthaka kakhulu. Ngokwengeza inkambo kavithamini A emfushane yokondla noma yokunisela, okunye ukugula kungavinjelwa, njengoba ngaphandle kukavithamini A owanele, izinyoni zingabanjwa ngamagciwane amaningi ayingozi.
UVitamin A ubalulekile ekukhuleni okunempilo kwezilwane ezincelisayo, ukugcina ukudla kahle, ukugqoka impilo nokuzivikela komzimba.
Amaqiniso anentshisekelo ngevithamini A
- yivithamini yokuqala etholwe ngabantu;
- isibindi se-polar bear sicebile ku-vitamin A kangangokuba ukudla sonke isibindi kungabulala abantu;
- cishe izingane eziyizigidi ezingama-259 kuye kwezingu-500 zilahlekelwa ukubona unyaka nonyaka ngenxa yokushoda kukavithamini A;
- kuzimonyo, uvithamini A uvame ukutholakala ngaphansi kwamagama i-Retinol acetate, i-retinyl linoleate ne-retinyl palmitate;
- Irayisi enevithamini A, eyakhiwa cishe eminyakeni eyi-15 eyedlule, ingavimbela amakhulu ezinkulungwane zamacala wobumpumputhe ezinganeni. Kepha ngenxa yokukhathazeka ngokudla okushintshwe izakhi zofuzo, akukaze kufakwe ekukhiqizweni.
Izakhiwo eziyingozi zikavithamini A, ukuphikisana kwayo nezixwayiso
UVitamin A umelana nokushisa okuphezulu, kepha ubhujiswa yilanga. Ngakho-ke, gcina ukudla okunothe amavithamini kanye nezengezo zezokwelapha endaweni emnyama.
Izimpawu Zokushoda Kuka-Vitamin A.
Ukushoda kukavithamini A kuvame ukwenzeka ngenxa yokungadli okwanele kokudla okunevithamini A, beta-carotene noma enye i-provitamin A carotenoids; ezithathwa njengevithamini A emzimbeni. Ngaphezu kwezinkinga zokudla, ukusetshenziswa ngokweqile kophuzo oludakayo kanye ne-malabsorption kungaba nomthelela ekushodeni kukavithamini A.
Uphawu lokuqala lokushoda kukavithamini A ukungaboni kahle ebumnyameni, noma ebumpumputhe ebusuku. Ukushoda okunamandla noma isikhathi eside kukavithamini A kudala ushintsho kumaseli we-cornea, okugcina kuholele ezilondeni ze-corneal. Ukushoda kukavithamini A ezinganeni emazweni asathuthuka kuyimbangela ehamba phambili yobumpumputhe.
Ukushoda kukavithamini A kuxhumene nokuntuleka komzimba, kunciphisa amandla okulwa nezifo. Ngisho nezingane ezinokushoda okuncane kukavithamini A zinezinga eliphakeme lezifo zokuphefumula nohudo, kanye nezinga lokufa eliphakeme ezifweni ezithathelwanayo (ikakhulukazi), uma kuqhathaniswa nezingane ezidla inani elanele likavithamini A. Ngaphezu kwalokho, ukuntuleka kukavithamini A kungadala ukukhula okungakhuli kahle nokwakheka kwamathambo ezinganeni nasebusheni. Kubantu ababhemayo, ukuntuleka kukavithamini A kungaba nomthelela esigulini esingapheliyo se-pulmonary disease (COPD) ne-emphysema, okucatshangwa ukuthi kwandisa ingozi yomdlavuza wamaphaphu.
Izimpawu zevithamini A eyeqile
I-vitamin A hypervitaminosis ebangelwa yimithamo ephezulu kakhulu ye-Retinol, eshutheka ngokushesha futhi ikhishwe kancane emzimbeni, ayijwayelekile. Izimpawu zifaka isicanucanu, ikhanda, ukukhathala, ukungathandi ukudla, isiyezi, isikhumba esomile ne-cerebral edema. Kunezifundo ezifakazela ukuthi ukwedlula isikhathi eside kukavithamini A emzimbeni kungaholela ekukhuleni kwamathambo. Izakhi ezithile ze-Retinol zokwenziwa (isb. I-tretinate, isotretinoin, tretinoin) zingadala ukukhubazeka kumbungu ngakho-ke akufanele zisetshenziswe ngesikhathi sokukhulelwa noma lapho kuzanywa ukukhulelwa. Ezimweni ezinjalo, i-beta-carotene ibhekwa njengomthombo ophephe kakhulu kavithamini A.
Imiphumela evela ku-Beta-Carotene ne-Retinol Efficacy Study (CARET) ikhombisa ukuthi i-vitamin A (Retinol) ne-beta-carotene supplementation yesikhathi eside kufanele igwenywe esikhathini eside kubantu abasengozini enkulu yomdlavuza wamaphaphu, njengabantu ababhemayo nabantu abadaluliwe ku-asbestosi.
Ukusebenzelana neminye imikhiqizo yokwelapha
I-Vitamin A, esivele ingene egazini, iqala ukonakala ngokushesha uma umzimba ungenawo uvithamini E. Futhi uma i-vitamin B4 (choline) ishoda, i-vitamin A ayigcinelwa ukusetshenziswa esikhathini esizayo. Imithi elwa namagciwane kucatshangwa ukuthi inciphisa kancane imiphumela kavithamini A. Ngaphezu kwalokho, uvithamini A ungadala imiphumela yento ebizwa nge-isotretinoin futhi idale imiphumela emibi kakhulu.
Siqoqe amaphuzu abaluleke kakhulu ngevithamini A kulo mfanekiso futhi sizojabula uma wabelana ngesithombe kwinethiwekhi yokuxhumana noma kubhulogi, ngesixhumanisi saleli khasi:
- Isihloko se-Wikipedia "Vitamin A"
- IBritish Medical Association. I-AZ Family Medical Encyclopedia
- UMaria Polevaya. Izaqathe ezilwa nezicubu kanye ne-urolithiasis.
- UVladimir Kallistratov Lavrenov. I-Encyclopedia Yezitshalo Zokwelapha Ngokwamasiko.
- Amaprotheni alawula izindlela zikavithamini A zokuvimbela umzimba, evimbela ukuvuvukala,
- Indima kavithamini A oshukela,
- Umphumela ka-vitamin A owawungaziwa ngaphambilini,
- UWalter A. Droessler. Kumnandi kanjani ukudla futhi ubukeka umuhle (ikhasi 64)
- Imininingwane yolwakhiwo lwe-USDA,
Ukusetshenziswa kwanoma iyiphi into ngaphandle kwemvume yethu ebhaliwe akuvunyelwe.
Abaphathi ababophezelekile kunoma imuphi umzamo wokusebenzisa noma iyiphi iresiphi, iseluleko noma ukudla, futhi futhi akuqinisekisi ukuthi imininingwane ebekiwe izokusiza noma ikulimaze wena uqobo. Hlakanipha futhi ngaso sonke isikhathi uthintane nodokotela ofanele!