Vitamini A: maubwino, Kuperewera, poizoni ndi zina zambiri

Zamkati

• Kodi Vitamini A ndi Chiyani?
• Nchito m'thupi lanu
• Mapindu azaumoyo
• Antioxidant Wamphamvu
• Chofunikira pa Thanzi Labwino ndikuletsa Kusintha kwa Macular
• Mutha Kuteteza Kansa Ina
• Chofunikira pa Kubala ndi Kukula Kwa Khanda
• Kumalimbitsa Chitetezo Cha M'thupi Lanu
• Kuperewera
• Zakudya
• Malangizo Azoopsa ndi Mlingo
• Mfundo Yofunika Kwambiri

Vitamini A ndi chopatsa thanzi chosungunuka chomwe chimagwira gawo lofunikira mthupi lanu.

Zilipo mwachilengedwe pazakudya zomwe mumadya ndipo amathanso kudyedwa ndi zowonjezera.

Nkhaniyi ikufotokoza za vitamini A, kuphatikiza maubwino ake, magwero a chakudya, komanso zovuta zakusowa ndi kawopsedwe.

Kodi Vitamini A ndi Chiyani?

Ngakhale kuti vitamini A nthawi zambiri imawerengedwa kuti ndi michere, ndi dzina la gulu la zinthu zosungunuka ndi mafuta, kuphatikiza retinol, retinal ndi retinyl esters ().

Pali mitundu iwiri ya vitamini A yomwe imapezeka mchakudya.

Mavitamini A opangidwa kale - retinol ndi retinyl esters - amapezeka makamaka muzogulitsa nyama, monga mkaka, chiwindi ndi nsomba, pomwe provitamin A carotenoids imapezeka muzakudya zambiri zamasamba monga zipatso, ndiwo zamasamba ndi mafuta ().

Kuti muzigwiritsa ntchito, thupi lanu liyenera kusintha mitundu yonse ya vitamini A kukhala retinal ndi retinoic acid, mitundu yogwira ntchito ya vitamini.

Chifukwa vitamini A ndi mafuta osungunuka, amasungidwa mthupi kuti adzawagwiritse ntchito mtsogolo.

Mavitamini A ambiri m'thupi lanu amasungidwa m'chiwindi mwanu ngati ma retinyl esters ().

Ma ester awa amathyoledwa kukhala trans-retinol yonse, yomwe imamangiriza ku mapuloteni omangiriza a retinol (RBP). Kenako imalowa m'magazi anu, pomwe thupi lanu limatha kugwiritsa ntchito ().

Vitamini A ndi dzina lodziwika bwino la gulu la zosungunuka zamafuta zomwe zimapezeka muzakudya za nyama ndi zomera.

Nchito m'thupi lanu

Vitamini A ndiyofunikira pa thanzi lanu, kuthandizira kukula kwama cell, chitetezo cha mthupi, kukula kwa mwana wosabadwayo komanso masomphenya.

Mwina imodzi mwazinthu zodziwika bwino za vitamini A ndi gawo lake m'masomphenya ndi thanzi lamaso.

Retinal, mtundu wa vitamini A, umagwirizana ndi protein opsin kupanga rhodopsin, molekyulu yofunikira pakuwona kwamitundu ndi kuwonera pang'ono ().

Zimathandizanso kuteteza ndi kusungitsa diso lam'maso - lakumapeto kwa diso lanu - ndi conjunctiva - nembanemba yopyapyala yomwe imaphimba diso lanu komanso mkati mwazikope zanu ().

Kuphatikiza apo, vitamini A imathandizira kukhalabe ndi khungu monga khungu, matumbo, mapapo, chikhodzodzo ndi khutu lamkati.

Imathandizira chitetezo cha mthupi pochirikiza kukula ndi kugawa kwa T-cell, mtundu wa khungu loyera lomwe limateteza thupi lanu ku matenda ().

Kuphatikiza apo, vitamini A imathandizira khungu lamtundu wathanzi, kubereka amuna ndi akazi komanso kukula kwa fetus ().

Vitamini A amafunikira thanzi lamaso, masomphenya, chitetezo chamthupi, kukula kwamaselo, kubereka komanso kukula kwa mwana.

Mapindu azaumoyo

Vitamini A ndi michere yofunika yomwe imapindulitsa thanzi m'njira zambiri.

Antioxidant Wamphamvu

Provitamin A carotenoids monga beta-carotene, alpha-carotene ndi beta-cryptoxanthin ndizomwe zimayambitsa vitamini A ndipo zimakhala ndi antioxidant.

Carotenoids imalimbana ndi ma radicals aulere - mamolekyulu otakasika kwambiri omwe angawononge thupi lanu pakupanga kupsinjika kwa okosijeni ().

Kupsinjika kwa oxidative kumalumikizidwa ndi matenda osiyanasiyana monga matenda a shuga, khansa, matenda amtima komanso kuchepa kwazindikiritso ().

Zakudya zomwe zili ndi carotenoids zimayenderana ndi chiopsezo chochepa cha izi, monga matenda amtima, khansa yam'mapapo ndi shuga (,,).

Chofunikira pa Thanzi Labwino ndikuletsa Kusintha kwa Macular

Monga tafotokozera pamwambapa, vitamini A ndikofunikira pakuwona komanso kukhala ndi thanzi lamaso.

Kudya chakudya chokwanira cha vitamini A kumathandiza kuteteza kumatenda ena amaso, monga kuchepa kwa makulidwe azaka (AMD).

Kafukufuku akuwonetsa kuti kuchuluka kwamagazi a beta-carotene, alpha-carotene ndi beta-cryptoxanthin kumachepetsa chiopsezo chanu cha AMD mpaka 25% ().

Kuchepetsa chiopsezo kumeneku kumalumikizidwa ndi chitetezo cha michere ya carotenoid yoteteza macular minofu pochepetsa kupsinjika kwa oxidative.

Mutha Kuteteza Kansa Ina

Chifukwa cha antioxidant, zipatso ndi ndiwo zamasamba zolemera ndi carotenoid zitha kuteteza ku mitundu ina ya khansa.

Mwachitsanzo, kafukufuku woposa akulu 10,000 adazindikira kuti osuta omwe ali ndi magazi apamwamba kwambiri a alpha-carotene ndi beta-cryptoxanthin anali ndi chiopsezo chotsika ndi 46% ndi 61% chomwalira ndi khansa yamapapu, motsatana, kuposa osasuta omwe amadya kwambiri Zakudya izi ().

Kuphatikiza apo, kafukufuku wapa test-tube akuwonetsa kuti ma retinoid amatha kulepheretsa kukula kwa maselo ena a khansa, monga chikhodzodzo, khansa ya m'mawere ndi yamchiberekero ().

Chofunikira pa Kubala ndi Kukula Kwa Khanda

Vitamini A ndiwofunikira pakuchulukitsa kwa amuna ndi akazi chifukwa kumathandiza pakukula kwa umuna ndi dzira.

Ndizofunikanso pakukhala ndi thanzi labwino, kukula kwa minofu ya fetus ndi kukonza, komanso kukula kwa fetus ().

Chifukwa chake, vitamini A imathandizanso paumoyo wa amayi ndi a fetus komanso kwa iwo omwe amayesera kutenga pakati.

Kumalimbitsa Chitetezo Cha M'thupi Lanu

Vitamini A imakhudza thanzi lathu poyambitsa mayankho omwe amateteza thupi lanu ku matenda ndi matenda.

Vitamini A imakhudzidwa pakupanga maselo ena, kuphatikiza ma B- ndi T-cell, omwe amakhala ndi gawo lofunikira pakuyankha mthupi komwe kumateteza matenda.

Kuperewera kwa michere imeneyi kumabweretsa kuchuluka kwama mamolekyulu otupa omwe amachepetsa kuyankha kwa chitetezo cha m'thupi ndikugwira ntchito ().

Vitamini A imakhudza thanzi lanu mwa kuchepetsa kupsinjika kwa makutidwe ndi okosijeni, kulimbikitsa chitetezo cha mthupi lanu komanso kuteteza matenda ena.

Kuperewera

Ngakhale kuchepa kwa vitamini A ndikosowa m'maiko otukuka ngati US, ndizofala m'maiko akutukuka, popeza anthuwa atha kukhala ndi mwayi wochepa wopezera zakudya za vitamini A komanso provitamin A carotenoids.

Kulephera kwa Vitamini A kumatha kubweretsa zovuta ku thanzi.

Malinga ndi WHO, kuchepa kwa vitamini A ndiye komwe kumayambitsa matenda akhungu mwa ana padziko lonse lapansi.

Kulephera kwa Vitamini A kumawonjezeranso kuopsa komanso chiopsezo chofa ndi matenda monga chikuku ndi kutsegula m'mimba (,).

Kuphatikiza apo, kuchepa kwa vitamini A kumadzetsa chiwopsezo cha kuchepa kwa magazi m'thupi komanso kumwalira kwa amayi apakati ndipo zimasokoneza mwanayo pochepetsa kukula ndi chitukuko ().

Zizindikiro zochepa za kuchepa kwa vitamini A zimaphatikizaponso khungu monga hyperkeratosis ndi ziphuphu (,).

Magulu ena monga makanda asanakwane, anthu omwe ali ndi cystic fibrosis komanso amayi apakati kapena oyamwitsa m'maiko omwe akutukuka ali pachiwopsezo chotaya vitamini A ().

Kuperewera kwa Vitamini A kumatha kubweretsa khungu, chiwopsezo chowonjezeka cha matenda opatsirana, zovuta zamimba komanso zovuta pakhungu.

Zakudya

Pali zakudya zambiri zomwe zimapangidwira kale vitamini A komanso provitamin A carotenoids.

Vitamini A wokonzedweratu amatengeka mosavuta ndikugwiritsidwa ntchito ndi thupi lanu kuposa magwero azitsamba a provitamin A carotenoids.

Kukhoza kwa thupi lanu kusintha bwino ma carotenoid, monga beta-carotene, kukhala vitamini A yogwira zimadalira pazinthu zambiri - kuphatikiza majini, zakudya, thanzi lathunthu ndi mankhwala ().

Pachifukwa ichi, iwo omwe amatsata zakudya zopangidwa ndi mbewu - makamaka vegans - ayenera kukhala tcheru kuti apeze zakudya zokwanira za carotenoid.

Zakudya zomwe zili ndi vitamini A wokonzedweratu ndi izi:

• Mazira a mazira
• Chiwindi cha ng'ombe
• Chiwombankhanga
• Batala
• Cod mafuta a chiwindi
• Chiwindi cha nkhuku
• Salimoni
• Tchizi cha Cheddar
• Soseji ya chiwindi
• Mfumu mackerel
• Nsomba ya trauti

Zakudya zomwe zili ndi provitamin A carotenoids monga beta-carotene ndizo (25, 26):

• Mbatata
• Dzungu
• Kaloti
• Kale
• Sipinachi
• Dandelion amadyera
• Kabichi
• Swiss chard
• Tsabola wofiira
• Maluwa a Collard
• Mochepera
• Sikwashi yam'madzi

Vitamini A wokonzedweratu amapezeka mu zakudya zanyama monga chiwindi, nsomba ndi mazira a dzira, pomwe provitamin A carotenoids imapezeka muzakudya zamasamba, kuphatikiza mbatata, kale ndi kabichi.

Malangizo Azoopsa ndi Mlingo

Monga momwe kusowa kwa vitamini A kumakhudzira thanzi, kuchuluka kwambiri kungakhale koopsa.

Ndalama yolimbikitsidwa tsiku ndi tsiku (RDA) ya vitamini A ndi 900 mcg ndi 700 mcg patsiku la amuna ndi akazi, motsatana - zomwe zimatha kupezeka mosavuta potsatira zakudya zonse (27).

Komabe, ndikofunika kuti musapitirire malire apamwamba (UL) a 10,000 IU (3,000 mcg) akuluakulu kuti ateteze poizoni (27).

Ngakhale ndizotheka kudya mavitamini A ochulukirachulukira kudzera mu ziweto monga chiwindi, poyizoni nthawi zambiri amalumikizidwa ndi kupatsidwa mankhwala owonjezera komanso mankhwala ena, monga Isotretinoin (,).

Popeza vitamini A imasungunuka mafuta, imasungidwa mthupi lanu ndipo imatha kufikira misinkhu yopanda thanzi pakapita nthawi.

Kutenga vitamini A wambiri kumatha kubweretsa zovuta zoyipa ndipo kumatha kupha ngati kumeza kwambiri.

Mavitamini oopsa a vitamini A amapezeka kwakanthawi kochepa pomwe mavitamini A amamwa kamodzi, mopitirira muyeso, pomwe poyizoni amapezeka nthawi yayitali kuposa 10 RDA imamwa nthawi yayitali ().

Zotsatira zoyipa kwambiri za vitamini A poyizoni wambiri - omwe nthawi zambiri amatchedwa hypervitaminosis A - ndi awa:

• Kusokonezeka kwamasomphenya
• Kuphatikizana ndi mafupa
• Kulakalaka kudya
• Nseru ndi kusanza
• Kuzindikira kwa dzuwa
• Kutaya tsitsi
• Mutu
• Khungu louma
• Kuwonongeka kwa chiwindi
• Jaundice
• Kukula kochedwa
• Kuchepetsa chilakolako
• Kusokonezeka
• Khungu loyabwa

Ngakhale sichicheperako poyerekeza ndi poyizoni wa vitamini A, mavitamini A owopsa amayambitsidwa ndi zizindikilo zowopsa, kuphatikiza kuwonongeka kwa chiwindi, kuchuluka kwa kuthamanga kwa cranial ngakhale kufa ().

Kuphatikiza apo, mavitamini A poizoni amatha kusokoneza thanzi la amayi ndi a fetus ndipo atha kubweretsa zolepheretsa kubadwa ().

Pofuna kupewa poizoni, pewani mavitamini A owonjezera.

UL wa vitamini A imagwira ntchito pazakudya zopangidwa ndi nyama za vitamini A, komanso zowonjezera mavitamini A.

Kudya kwambiri ma carotenoids sikumayenderana ndi kawopsedwe, ngakhale kuti kafukufuku amalumikiza beta-carotene zowonjezerapo ndi chiopsezo chowonjezeka cha khansa yamapapo ndi matenda amtima mwa omwe amasuta ().

Popeza kuchuluka kwa vitamini A kumatha kukhala kovulaza, funsani dokotala musanadye zowonjezera vitamini A.

Vitamini A kawopsedwe angayambitse zizindikiro, monga kuwonongeka kwa chiwindi, kusokonezeka kwa masomphenya, nseru komanso kufa. Mavitamini A okwera kwambiri ayenera kupewa pokhapokha ataperekedwa ndi dokotala wanu.

Mfundo Yofunika Kwambiri

Vitamini A ndi chopukutira mafuta chosungunuka chofunikira pakulimbitsa thupi, thanzi lamaso, kubereka komanso kukula kwa mwana.

Kulephera konse komanso kuchuluka kwa zakudya zambiri kumatha kuyambitsa zovuta zina, chifukwa chake ndikofunikira kukumana ndi RDA ya 700-900 mcg tsiku lililonse kwa achikulire, musapitirire malire apamwamba a tsiku ndi tsiku a 3,000 mcg.

Chakudya chopatsa thanzi, chopatsa thanzi ndi njira yabwino yoperekera thupi lanu ndi chakudya chopatsa thanzi.