UVitamin A: Izinzuzo, Ukushoda, Ubuthi nokunye

-Delile

• Yini uVithamini A?
• Imisebenzi Emzimbeni Wakho
• Izinzuzo Zezempilo
• I-Antioxidant enamandla
• Kubalulekile ku-Eye Health futhi kuvimbela ukwenziwa kwe-Macular Degeneration
• Kwangathi Kungavikelwa Eminye Imdlavuza
• Okubalulekile Ekuzala Nentuthuko Yengane
• Kuqinisa Amasosha Wakho Omzimba
• Ukushoda
• Imithombo Yokudla
• Izincomo Zobuthi Nesikali
• Okusemqoka

UVitamin A yisakhi esincibilikayo esinamafutha esidlala indima ebalulekile emzimbeni wakho.

Kukhona ngokwemvelo ekudleni okudlayo futhi kungasetshenziswa ngezithasiselo.

Lo mbhalo ukhuluma ngovithamini A, kufaka phakathi izinzuzo zawo, imithombo yokudla, kanye nemiphumela yokushoda nobuthi.

Yini uVithamini A?

Yize uvithamini A uvame ukubhekwa njengesakhi esisodwa, empeleni igama leqembu lama-compounds ancibilikisa amafutha, kufaka phakathi i-retinol, i-retinal kanye ne-retinyl esters ().

Kunezinhlobo ezimbili zikavithamini A ezitholakala ekudleni.

I-vitamin A eyenziwe kabusha - i-retinol ne-retinyl esters - ivela kuphela kwimikhiqizo yezilwane, njengobisi, isibindi nenhlanzi, kuyilapho i-provitamin A carotenoids inezinto eziningi ekudleni kwezitshalo njengezithelo, imifino kanye namafutha ().

Ukuze uwasebenzise, ​​umzimba wakho kufanele uguqule zombili izinhlobo zikavithamini A zibe i-retinal ne-retinoic acid, izinhlobo ezisebenzayo zevithamini.

Ngenxa yokuthi uvithamini A unamafutha ancibilikayo, ugcinwa ezicutshini zomzimba ukuze zisetshenziswe kamuva.

Iningi levithamini A elisemzimbeni wakho ligcinwa esibindini sakho ngendlela yama-retinyl esters ().

Lawa ma-esters abe esehlukaniswa abe yi-trans-retinol yonke, ebophezela kumaprotheni abopha i-retinol (RBP). Bese lingena egazini lakho, lapho umzimba wakho ungalisebenzisa khona ().

I-Vitamin A yigama elijwayelekile leqembu lama-compounds ancibilikayo anamafutha atholakala kokudla kwezilwane nezitshalo.

Imisebenzi Emzimbeni Wakho

IVitamin A ibalulekile empilweni yakho, isekela ukukhula kwamaseli, ukusebenza komzimba, ukukhula kombungu nokubona.

Mhlawumbe omunye wemisebenzi eyaziwa kakhulu kavithamini A yiqhaza lawo embonweni nasempilweni yamehlo.

I-Retinal, uhlobo olusebenzayo lukavithamini A, luhlangana ne-protein opsin ukwakha i-rhodopsin, i-molecule edingekayo ekuboneni umbala nokubona okuncane ().

Kuyasiza nokuvikela nokugcina i-cornea - ungqimba lwangaphandle lweso lakho - kanye ne-conjunctiva - ulwelwesi oluncane olumboze ubuso beso lakho nangaphakathi kwamajwabu amehlo akho ().

Ngokwengeziwe, uvithamini A usiza ukugcina izicubu ezingaphezulu kwesikhumba sakho, amathumbu, amaphaphu, isinye nendlebe yangaphakathi.

Isekela ukusebenza komzimba ngokusekela ukukhula nokusatshalaliswa kwama-T-cell, uhlobo lwamaseli amhlophe egazi avikela umzimba wakho ekuthelelekeni ().

Ngaphezu kwalokho, uvithamini A usekela amangqamuzana esikhumba aphilile, ukuzala kwabesilisa nabesifazane kanye nokukhula kombungu ().

UVitamin A uyadingeka empilweni yamehlo, ukubona, ukusebenza komzimba, ukukhula kwamaseli, ukuzala nokukhula kombungu.

Izinzuzo Zezempilo

UVitamin A yisakhi esibalulekile esizuzisa impilo ngezindlela eziningi.

I-Antioxidant enamandla

I-Provitamin A carotenoids efana ne-beta-carotene, i-alpha-carotene ne-beta-cryptoxanthin yizandulela zikavithamini A futhi zinezinto zokulwa ne-antioxidant.

AmaCarotenoids alwa nama-radicals amahhala - ama-molecule asebenza kakhulu angalimaza umzimba wakho ngokudala ukucindezeleka kwe-oxidative ().

Ukucindezeleka okwenziwe nge-oxidative kuye kwaxhunyaniswa nezifo ezahlukahlukene ezingamahlalakhona njengesifo sikashukela, umdlavuza, isifo senhliziyo kanye nokwehla kwengqondo ().

Ukudla okuphezulu kuma-carotenoids kuhlotshaniswa nengozi ephansi yezimo eziningi, njengesifo senhliziyo, umdlavuza wamaphaphu nesifo sikashukela (,,).

Kubalulekile ku-Eye Health futhi kuvimbela ukwenziwa kwe-Macular Degeneration

Njengoba kushiwo ngenhla, uvithamini A ubalulekile embonweni nasempilweni yamehlo.

Ukudla okwanele i-vitamin A kusiza ukuvikela ezifweni ezithile zamehlo, njengokuwohloka kwe-macular okuhlobene nobudala (i-AMD).

Ucwaningo lukhombisa ukuthi amazinga aphezulu egazi we-beta-carotene, alpha-carotene ne-beta-cryptoxanthin anganciphisa ubungozi be-AMD kuze kufike ku-25% ().

Lokhu kuncishiswa kobungozi kuxhunywe ekuvikeleni izakhi zomzimba ze-carotenoid ngezicubu ze-macular ngokwehlisa amazinga okuxineka kwe-oxidative.

Kwangathi Kungavikelwa Eminye Imdlavuza

Ngenxa yezinto zabo zokulwa ne-antioxidant, izithelo nemifino ecebile nge-carotenoid ingavikela ezinhlotsheni ezithile zomdlavuza.

Isibonelo, ucwaningo olwenziwe kubantu abadala abangaphezu kuka-10 000 luthole ukuthi ababhemayo abanamazinga aphezulu egazi e-alpha-carotene ne-beta-cryptoxanthin babe nengozi ephansi engama-46% kanye no-61% yokubulawa umdlavuza wamaphaphu, ngokulandelana, kunabantu abangabhemi abanokudla okuphansi kwalezi izakhamzimba ().

Ngaphezu kwalokho, izifundo ze-test-tube zibonisa ukuthi ama-retinoids angavimbela ukukhula kwamangqamuzana athile omdlavuza, njenge-bladder, umdlavuza webele nowe-ovarian ().

Okubalulekile Ekuzala Nentuthuko Yengane

IVitamin A ibalulekile ekukhiqizweni kowesilisa nowesifazane ngoba idlala indima ekukhuleni kwesidoda neqanda.

Kubaluleke kakhulu futhi empilweni yezitho zomzimba, ukuthuthukiswa kwezicubu zomntwana kanye nokugcinwa, kanye nokukhula kwe-fetus ().

Ngakho-ke, uvithamini A ubalulekile empilweni kamama neyomntwana kanye nalabo abazama ukukhulelwa.

Kuqinisa Amasosha Wakho Omzimba

Uvithamini A unomthelela empilweni yomzimba ngokuvuselela izimpendulo ezivikela umzimba wakho ezifweni nasezifweni.

Uvithamini A ubandakanyekile ekwakheni amaseli athile, kufaka phakathi ama-B- no-T-cell, adlala indima enkulu ekuphenduleni komzimba okuvikela izifo.

Ukushoda kwalesi sakhi kuholela emazingeni akhuphukile ama-molecule e-pro-inflammatory anciphisa ukuphendula kwamasosha omzimba nokusebenza ().

Uvithamini A uyithinta impilo ngokugcina ukucindezeleka kwe-oxidative, kukhulise amasosha akho omzimba nokuvikela ezifweni ezithile.

Ukushoda

Yize ukuntuleka kukavithamini A kuyivelakancane emazweni athuthukile njenge-US, kuvamile emazweni asathuthuka, njengoba laba bantu kungenzeka babe nokufinyelela okulinganiselwe emithonjeni yokudla ye-preformed vitamin A ne-provitamin A carotenoids.

Ukushoda kukavithamini A kungaholela ezinkingeni ezinkulu zempilo.

Ngokwe-WHO, ukushoda kukavithamini A kuyimbangela ehamba phambili yokungaboni okungavikeleka ezinganeni emhlabeni wonke.

Ukushoda kukavithamini A futhi kwandisa ubunzima kanye nengozi yokufa ngenxa yezifo ezifana nesimungumungwane nohudo (,).

Ngokwengeziwe, ukushoda kukavithamini A kukhuphula ubungozi bokushoda kwegazi nokufa kwabesifazane abakhulelwe futhi kuthinta kabi umbungu ngokunciphisa ukukhula nentuthuko ().

Izimpawu ezinzima kakhulu zokushoda kukavithamini A zifaka izingqinamba zesikhumba ezifana ne-hyperkeratosis kanye nezinduna (,).

Amaqembu athile anjengezingane ezizalwe ngaphambi kwesikhathi, abantu abane-cystic fibrosis nabesifazane abakhulelwe noma abancelisayo emazweni asathuthuka basengozini yokushoda kukavithamini A ().

Ukushoda kuka-Vitamin A kungaholela ekungaboni, ukwanda kwengozi yokutheleleka, izinkinga zokukhulelwa kanye nezinkinga zesikhumba.

Imithombo Yokudla

Kunemithombo eminingi yokudla kokubili i-vitamin A eyenziwe ngaphambilini ne-provitamin A carotenoids.

IVithamini A eyenziwe ngaphambili ifakwa kalula futhi isetshenziswe ngumzimba wakho kunemithombo esuselwa ezitshalweni ye-provitamin A carotenoids.

Amandla omzimba wakho wokuguqula ngempumelelo ama-carotenoid, njenge-beta-carotene, abe uvithamini A osebenzayo kuncike ezintweni eziningi - kufaka phakathi ufuzo, ukudla, impilo yonke kanye nemithi ().

Ngalesi sizathu, labo abalandela ukudla okususelwa ezitshalweni - ikakhulukazi ama-vegans - kufanele baqaphele ukuthola ukudla okwanele okunothe kwe-carotenoid.

Ukudla okuphezulu kakhulu ku-vitamin A owenziwe ngaphambili yilokhu:

• Izikhupha zamaqanda
• Isibindi senkomo
• Isibindi
• Ibhotela
• Uwoyela we-cod wesibindi
• Inkukhu yesibindi
• Uhlobo lwenhlanzi
• Ushizi kaCheddar
• Umvimba wesibindi
• King mackerel
• Ithrawuthi

Ukudla okuphezulu ku-provitamin A carotenoids njenge-beta-carotene kufaka (25, 26):

• Ubhatata
• Ithanga
• Izaqathe
• Kale
• Isipinashi
• Imifino yedandelion
• Iklabishi
• I-Swiss chard
• Upelepele obomvu
• Imifino yeCollard
• Kancane
• Isikwashi se-Butternut

IVithamini A eyenziwe ngaphambilini ikhona ekudleni kwezilwane njengesibindi, isalmon kanye namaqanda amaqanda, kuyilapho i-provitamin A carotenoids itholakala ekudleni kwezitshalo, kufaka phakathi ubhatata, i-kale neklabishi.

Izincomo Zobuthi Nesikali

Njengoba ukuntuleka kukavithamini A kungaba nomthelela omubi empilweni, ukuthola okuningi kakhulu nakho kungaba yingozi.

Isabelo esinconywayo sansuku zonke (i-RDA) sevithamini A singama-900 mcg kanye nama-700 mcg ngosuku kwabesilisa nabesifazane, ngokulandelana - okungafinyelelwa kalula ngokulandela ukudla kokudla okuphelele (27).

Kodwa-ke, kubalulekile ukuthi ungeqi umkhawulo ongaphezulu ongabekezeleleka (UL) we-10,000 IU (3,000 mcg) wabantu abadala ukuvimbela ubuthi (27).

Yize kungenzeka ukuthi kudle uvithamini A owenziwe ngokweqile ngokweqile ngemithombo esekwe ezilwaneni njengesibindi, ubuthi buvame kakhulu ukuxhunyaniswa nokudla ngokweqile nokwelashwa ngemithi ethile, efana ne-Isotretinoin (,).

Njengoba uvithamini A ancibilika emafutheni, igcinwa emzimbeni wakho futhi ingafinyelela emazingeni angenampilo ngokuhamba kwesikhathi.

Ukuthatha uvithamini A omningi kakhulu kungaholela emiphumeleni emibi kakhulu futhi kungabulala ngisho nokufa uma ungeniswe ngemithamo ephezulu kakhulu.

I-vitamin A toxicity enobuthi yenzeka esikhathini esifushane lapho kudliwe umthamo owodwa, ophakeme ngokweqile kavithamini A, kuyilapho ubuthi obungapheli benzeka lapho imithamo iphindwe izikhathi ezingaphezu kwezingu-10 i-RDA ifakwa esikhathini eside ().

Imiphumela emibi kakhulu ye-vitamin A enobuthi engapheli - evame ukubizwa ngokuthi yi-hypervitaminosis A - ifaka:

• Ukuphazamiseka kombono
• Ubuhlungu obuhlangene nobethambo
• Ukudla okungekuhle
• Isicanucanu nokuhlanza
• Ukuzwela kwelanga
• Ukulahleka kwezinwele
• Ubuhlungu bekhanda
• Isikhumba esomile
• Ukulimala kwesibindi
• I-jaundice
• Ukukhula okubambezelekile
• Ukwehla kwesifiso sokudla
• Ukudideka
• Isikhumba esilumayo

Yize ingajwayelekile kangako kunobuthi obungamahlalakhona be-vitamin A, i-vitamin A enobuthi ihambisana nezimpawu ezinzima kakhulu, kufaka phakathi ukulimala kwesibindi, ukukhuphuka kwengcindezi ye-cranial ngisho nokufa ().

Ngaphezu kwalokho, ubuthi bukavithamini A bungaba nomthelela omubi empilweni kamama nengane futhi kungaholela ekukhubazekeni kokuzalwa ().

Ukugwema ubuthi, hlukana nezithasiselo ezinomthamo omkhulu kavithamini A.

I-UL kavithamini A isebenza kwimithombo yokudla esuselwa ezilwaneni kavithamini A, kanye nezengezo zikavithamini A.

Ukudla okuphezulu kwama-carotenoid okudla akuhlotshaniswa nobuthi, yize izifundo zixhumanisa izengezo ze-beta-carotene ngengozi eyengeziwe yomdlavuza wamaphaphu nesifo senhliziyo kubantu ababhemayo ().

Njengoba uvithamini A omningi kakhulu angaba yingozi, thintana nodokotela wakho ngaphambi kokuthatha izengezo zikavithamini A.

U-Vitamin A ubuthi ungadala izimpawu, njengokulimala kwesibindi, ukuphazamiseka kombono, isicanucanu nokufa imbala. Izithako eziphezulu zevithamini A kufanele zigwenywe ngaphandle uma kuchazwe ngudokotela wakho.

Okusemqoka

UVitamin A yisakhi esincibilikayo esinamafutha esibalulekile ekusebenzeni komzimba, impilo yamehlo, ukuzala kanye nokukhula kombungu.

Kokubili ukuntuleka nokudla okusele kungadala imiphumela emibi kakhulu, ngakho-ke yize kubalulekile ukuhlangabezana ne-RDA engu-700-900 mcg nsuku zonke kubantu abadala, ungeqi umkhawulo wansuku zonke ophezulu we-3,000 mcg.

Ukudla okunempilo, okulinganisela kahle kuyindlela enhle yokunikeza umzimba wakho inani eliphephile lalesi sakhi somzimba esibalulekile.