Vithamine A: Melemo, Khaello, Chefo le Tse ling

Litaba

• Vithamine A ke eng?
• Mesebetsi 'meleng oa hau
• Melemo ea bophelo bo botle
• Antioxidant e matla
• E bohlokoa bakeng sa Bophelo ba Mahlo mme e Thibela Tlholeho ea Macular
• E kanna ea Sireletsa Khahlanong le Kankere e itseng
• E bohlokoa bakeng sa ho emola le kholo ea lesea
• E matlafatsa sesole sa hau sa 'mele
• Khaello
• Mehloli ea Lijo
• Litlhahiso tsa Chefo le Tekanyo
• Ntlha ea Bohlokoa

Vithamine A ke phepo e qhibilihang mafura e phethang karolo ea bohlokoa 'meleng oa hau.

E teng ka tlhaho lijong tseo u li jang hape e ka jeoa ka li-supplement.

Sengoliloeng sena se bua ka vithamine A, ho kenyelletsa melemo ea eona, mehloli ea lijo, le litlamorao tsa khaello le chefo.

Vithamine A ke eng?

Le ha vithamine A hangata e nkuoa e le phepo e le 'ngoe, ehlile ke lebitso la sehlopha sa metsoako e qhibilihang mafura, ho kenyelletsa le li-retinol, li-retina le li-estinyl esters ().

Ho na le mefuta e 'meli ea vithamine A e fumanoang lijong.

Li-vithamine A tse entsoeng esale pele - li-retinol le li-retinyl esters - li etsahala feela lihlahisoa tsa liphoofolo, joalo ka lebese, sebete le tlhapi, ha provitamin A carotenoids e le ngata lijong tsa limela tse kang litholoana, meroho le lioli ().

E le ho li sebelisa, 'mele oa hau o tlameha ho fetola mefuta e' meli ea vithamine A ho e etsa retina le retinoic acid, e leng mefuta ea vithamine.

Hobane vithamine A e qhibiliha mafura, e bolokiloe ka liseleng tsa 'mele hore e tle e sebelisoe hamorao.

Boholo ba vithamine A 'meleng oa hau bo bolokiloe sebeteng sa hau ka mofuta oa li-retinyl esters ().

Li-esters tsena li se li arotsoe ho trans-retinol eohle, e tlamang liprotheine tse tlamang tsa retinol (RBP). Ebe e kena maling a hau, ka nako eo 'mele oa hau o ka e sebelisa ().

Vithamine A ke lentsoe le tloaelehileng bakeng sa sehlopha sa metsoako e qhibilihang mafura e fumanoang lijong tsa liphoofolo le tsa limela.

Mesebetsi 'meleng oa hau

Vithamine A e bohlokoa molemong oa bophelo ba hau, ho ts'ehetsa kholo ea lisele, ts'ebetso ea 'mele ea ho itšireletsa mafung, kholo ea lesea le pono.

Mohlomong o mong oa mesebetsi e tsebahalang haholo ea vithamine A ke karolo ea eona ponong le bophelo bo botle ba mahlo.

Retinal, mofuta o sebetsang oa vithamine A, o kopana le protheine opsin ho theha rhodopsin, molek'hule e hlokahalang bakeng sa pono ea mmala le pono e fokolang ea khanya ().

E boetse e thusa ho sireletsa le ho boloka cornea - lera le ka ntle la leihlo la hau - le conjunctiva - lera le lesesaane le koahelang bokaholimo ba leihlo la hao le kahare ho mahlo a hao a mahlo ().

Ntle le moo, vithamine A e thusa ho boloka lisele tse kaholimo tse kang letlalo la hao, mala, matšoafo, senya le tsebe e ka hare.

E ts'ehetsa boits'ireletso ba mmele ka ho ts'ehetsa kholo le kabo ea li-T-cell, mofuta oa sele e tšoeu ea mali e sirelletsang mmele oa hau ho tsoaetso ().

Ho feta moo, vithamine A e tšehetsa lisele tsa letlalo tse phetseng hantle, ho ikatisa ha banna le basali le kholo ea lesea ().

Vithamine A ea hlokahala bakeng sa bophelo bo botle ba mahlo, pono, boits'ireletso ba mmele, kholo ea sele, ho ikatisa le kholo ea lesea.

Melemo ea bophelo bo botle

Vithamine A ke phepo ea bohlokoa e thusang bophelo bo botle ka litsela tse ngata.

Antioxidant e matla

Provitamin A carotenoids joalo ka beta-carotene, alpha-carotene le beta-cryptoxanthin ke li-precursor tsa vithamine A ebile li na le thepa ea antioxidant.

Li-carotenoids li loantša li-radicals tsa mahala - limolek'hule tse sebetsang haholo tse ka lematsang 'mele oa hau ka ho baka khatello ea mali ().

Ho imeloa kelellong ho hokahantsoe le mafu a fapa-fapaneng a sa foleng a kang lefu la tsoekere, mofetše, lefu la pelo le ho fokotseha ha mohopolo ().

Lijo tse nang le li-carotenoid tse ngata li amahanngoa le kotsi e tlase ea maemo ana a mangata, joalo ka lefu la pelo, mofetše oa matšoafo le lefu la tsoekere (,,).

E bohlokoa bakeng sa Bophelo ba Mahlo mme e Thibela Tlholeho ea Macular

Joalokaha ho boletsoe kaholimo, vithamine A e bohlokoa molemong oa pono le bophelo bo botle ba mahlo.

Ho ja lijo tse lekaneng tsa vithamine A ho thusa ho itšireletsa khahlanong le maloetse a itseng a mahlo, a kang ho senyeha ha macular ho amanang le lilemo (AMD).

Liphuputso li bonts'a hore maemo a phahameng a mali a beta-carotene, alpha-carotene le beta-cryptoxanthin a ka fokotsa kotsi ea hau ea AMD ho fihlela ho 25% ().

Phokotso ena ea likotsi e hokahane le ts'ireletso ea limatlafatsi tsa carotenoid ea lisele tsa macular ka ho theola maemo a khatello ea mali.

E kanna ea Sireletsa Khahlanong le Kankere e itseng

Ka lebaka la thepa ea tsona ea antioxidant, litholoana le meroho tse nang le carotenoid li ka sireletsa mefuta e itseng ea mofets'e.

Mohlala, phuputso ho batho ba baholo ba fetang 10 000 e ile ea etsa qeto ea hore batho ba tsubang ba nang le maemo a phahameng ka ho fetisisa a mali a alpha-carotene le beta-cryptoxanthin ba na le kotsi e tlase ea 46% le 61% ea ho bolaoa ke mofetše oa matšoafo, ho fapana le batho ba sa tsubeng tsa limatlafatsi tsena).

Ho feta moo, lithuto tsa li-test-tube li bontša hore li-retinoids li kanna tsa thibela kholo ea lisele tse itseng tsa mofets'e, joalo ka kankere ea senya, ea matsoele le ea mae a bomme ().

E bohlokoa bakeng sa ho emola le kholo ea lesea

Vithamine A e bohlokoa bakeng sa ho ikatisa ha banna le basali hobane e bapala karolo ea kholo ea peo le lehe.

Ho bohlokoa hape bakeng sa bophelo bo botle ba 'mele, nts'etsopele ea lisele tsa "fetal" le tlhokomelo, hammoho le kholo ea "fetal" (".

Ka hona, vithamine A e bohlokoa ho bophelo ba bakhachane le ba lesea le ho ba lekang ho emola.

E matlafatsa sesole sa hau sa 'mele

Vitamin A e ama bophelo bo botle ba 'mele ka ho matlafatsa likarabo tse sireletsang' mele oa hau mafung le tšoaetsong.

Vithamine A e kentse letsoho ho theheng lisele tse itseng, ho kenyeletsoa B- le T-cell, tse phethang karolo ea mantlha likarabong tsa boits'ireletso tse sirelletsang mafu.

Ho haella ha phepo ena ho lebisa ho maemo a eketsehileng a limolek'hule tse ruruhang tse fokotsang karabelo ea sesole sa 'mele le ts'ebetso ().

Vithamine A e ama bophelo bo botle ka ho boloka khatello ea mali e le matla, e matlafatsa sesole sa hau sa 'mele le ho itšireletsa mafung a itseng.

Khaello

Le ha khaello ea vithamine A e sa fumanehe linaheng tse tsoetseng pele joalo ka US, ho atile linaheng tse tsoelang pele, kaha baahi bana ba kanna ba ba le phihlello e fokolang ea mehloli ea lijo ea vithamine A e entsoeng esale pele le provitamin A carotenoids.

Ho haella ha vithamine A ho ka lebisa ho mathata a tebileng a bophelo bo botle.

Ho ea ka WHO, khaello ea vithamine A ke sesosa se ka sehloohong sa bofofu bo ka thibeloang ho bana lefatšeng ka bophara.

Ho haella ha vithamine A ho boetse ho eketsa ho teba le kotsi ea ho bolaoa ke mafu a kang maselese le letshollo (,).

Ho feta moo, khaello ea vithamine A e baka kotsi ea phokolo ea mali le lefu ho basali ba bakhachane mme e ama lesea le ka mpeng hampe ka ho liehisa kholo le kholo ().

Matšoao a fokolang a ho haella ha vithamine A a kenyelletsa litaba tsa letlalo joalo ka hyperkeratosis le makhopho (,).

Lihlopha tse ling tse kang masea a tlang pele ho nako, batho ba nang le cystic fibrosis le basali ba baimana kapa ba anyesang linaheng tse tsoelang pele ba kotsing ea ho haelloa ke vithamine A ().

Ho haella ha vithamine A ho ka lebisa bofofu, ho eketsa ts'oaetso ea tšoaetso, mathata a bokhachane le mathata a letlalo.

Mehloli ea Lijo

Ho na le mehloli e mengata ea phepo ea vithamine A le preitamin A carotenoids.

Vithamine A e entsoeng esale pele e kenella habonolo le ho sebelisoa ke 'mele oa hau ho feta mehloli ea semela ea provitamin A carotenoids.

Bokhoni ba 'mele oa hau ba ho fetola li-carotenoid ka nepo, joalo ka beta-carotene, hore e be vithamine A e sebetsang e ipapisitse le lintlha tse ngata - ho kenyeletsoa liphatsa tsa lefutso, lijo, bophelo bo botle ka kakaretso le meriana ().

Ka lebaka lena, ba latelang lijo tse thehiloeng lijalong - haholo-holo vegans - ba lokela ho ba seli mabapi le ho fumana lijo tse lekaneng tsa carotenoid.

Lijo tse phahameng ka ho fetisisa ho vithamine A e entsoeng esale pele ke:

• Mahe a linotši
• Sebete sa nama ea khomo
• Sebete
• Botoro
• Oli ea sebete sa cod
• Khoho ea sebete
• Salemone
• Cheese ea Cheddar
• Boroso ea sebete
• King mackerel
• Trout

Lijo tse nang le provitamin A carotenoids joalo ka beta-carotene li kenyelletsa (25, 26):

• Litapole tse monate
• Mokopu
• Lihoete
• Khale
• Sepinichi
• Meroho ea Dandelion
• Khábeche
• Chard ea Switzerland
• Pelepele e khubelu
• Meroho ea Collard
• Hanyane
• Mokopu oa butternut

Vithamine A e entsoeng esale pele e teng lijong tsa liphoofolo tse kang sebete, salmon le mahe a mahe, ha provitamin A carotenoids e fumanoa lijong tsa limela, ho kenyeletsoa litapole, khale le k'habeche.

Litlhahiso tsa Chefo le Tekanyo

Joalo ka ha khaello ea vithamine A e ka ama bophelo bo botle hampe, ho fumana e ngata haholo le hona ho ka ba kotsi.

Kabelo e khothalletsoang ea letsatsi le letsatsi (RDA) ea vithamine A ke 900 mcg le 700 mcg ka letsatsi bakeng sa banna le basali, ka ho latellana - e ka fihlelloang habonolo ka ho latela lijo tsa lijo tse felletseng (27).

Leha ho le joalo, ho bohlokoa hore o se ke oa feta moeli o ka holimo o mamellehang (UL) oa 10,000 IU (3,000 mcg) bakeng sa batho ba baholo ho thibela chefo (27).

Le ha ho khonahala ho sebelisa vithamine A e fetisitsoeng esale pele ka mehloli ea liphoofolo joalo ka sebete, chefo e hokahantsoe le tlatsetso ea kalafo le kalafo ka meriana e itseng, joalo ka Isotretinoin (,).

Kaha vithamine A e qhibiliha mafura, e bolokiloe 'meleng oa hau mme e ka fihla maemong a sa pheleng hantle ha nako e ntse e tsamaea.

Ho nka vithamine A e ngata haholo ho ka lebisa litlamorao tse mpe mme ho ka ba ha bolaea haeba o nooa ka tekanyetso e phahameng haholo.

Chefo e matla ea vithamine A e etsahala ka nako e khuts'oane ha ho nooa vithamine A e le 'ngoe, ha chefo e sa foleng e hlaha ha tekanyetso e fetang makhetlo a 10 RDA e kenoa ka nako e telele ().

Litla-morao tse tloaelehileng haholo tsa chefo ea vithamine A e sa foleng - eo hangata e bitsoang hypervitaminosis A - e kenyelletsa:

• Pherekano ea pono
• Bohloko bo kopaneng le ba masapo
• Takatso e fosahetseng ea lijo
• Ho nyekeloa le ho hlatsa
• Kutloisiso ea khanya ea letsatsi
• Ho hlotheha ha moriri
• Ho tšoaroa ke hlooho
• Letlalo le ommeng
• Tšenyo ea sebete
• Jaundice
• Kholo e liehang
• Ho fokotsa takatso ea lijo
• Pherekano
• Letlalo le hlohlona

Le ha e sa tloaeleha hakaalo ho feta chefo ea vithamine A e sa foleng, vithamine A e chefo e amanang le matšoao a matla haholo, ho kenyelletsa tšenyo ea sebete, khatello e matla ea cranial esita le lefu ().

Ho feta moo, chefo ea vithamine A e ka ama bophelo ba bakhachane le ba lesea le bobe mme e ka lebisa ho likoli tsa pelehi ().

E le ho qoba chefo, qoba li-supplement tsa vithamine A tse phahameng.

UL bakeng sa vithamine A e sebetsa mehloling ea lijo tse thehiloeng liphoofolong ea vithamine A, hammoho le livithamini A.

Ho ja haholo li-carotenoids ha ho amane le chefo, leha lithuto li hokahanya beta-carotene e tlatsetsang ka kotsi e kholo ea mofetše oa matšoafo le lefu la pelo ho batho ba tsubang ().

Kaha vithamine A e ngata haholo e ka ba kotsi, ikopanye le ngaka ea hau pele u noa li-supplement tsa vithamine A.

Vitamin A chefo e ka baka matšoao, joalo ka tšenyo ea sebete, pherekano ea pono, ho nyekeloa ke pelo esita le lefu. Lisebelisoa tse phahameng tsa vithamine A li lokela ho qojoa ntle le haeba ngaka ea hau e u laetse.

Ntlha ea Bohlokoa

Vitamin A ke phepo e qhibilihang mafura e bohlokoa molemong oa boits'ireletso ba mmele, bophelo ba mahlo, ho ikatisa le kholo ea lesea.

Ho haella le ho ja ka bongata ho ka baka litla-morao tse matla, ka hona le ha ho le bohlokoa ho kopana le RDA ea 700-900 mcg letsatsi le letsatsi bakeng sa batho ba baholo, u se ke oa feta moeli o kaholimo oa letsatsi le letsatsi oa 3,000 mcg.

Lijo tse phetseng hantle, tse leka-lekaneng ke tsela e ntle ea ho fa 'mele oa hau palo e sireletsehileng ea limatlafatsi tsena tsa bohlokoa.