Vitamin A

Vitamin A yog hom vitamin-fat-soluble uas muab khaws cia hauv lub siab.

Muaj ob hom vitamin A uas pom hauv kev noj haus.

• Preformed vitamin A muaj nyob hauv cov tsiaj xws li nqaij, ntses, nqaij qaib, thiab khoom noj siv mis.
• Provitamin A pom muaj hauv cov khoom noj cog qoob loo xws li txiv hmab txiv ntoo thiab zaub. Qhov feem ntau hom pro-vitamin A yog beta-carotene.

Vitamin A kuj tseem muaj nyob hauv kev pabcuam noj haus. Nws feem ntau tau los hauv daim ntawv ntawm retinyl acetate lossis retinyl palmitate (preformed vitamin A), beta-carotene (provitamin A) los yog kev sib txuas ntawm preformed thiab provitamin A.

Vitamin A pab tsim thiab tswj cov hniav zoo, cev pob txha thiab cov nqaij mos, hnoos qeev, thiab tawv nqaij. Nws kuj tseem hu ua retinol vim tias nws ua cov pigments hauv retina ntawm lub qhov muag.

Vitamin A txhawb nqa kev pom kev zoo, tshwj xeeb hauv lub teeb qis. Nws tseem muaj lub luag haujlwm hauv kev xeeb tub thiab kev pub mis niam.

Vitamin A pom muaj ob hom:

• Retinol: Retinol yog ib hom vitamin A. Nws muaj nyob hauv tsiaj daim siab, mis nyuj, thiab qee yam zaub mov muaj zog.
• Carotenoids: Carotenoids yog cov xim tsaus xim (cov xim). Lawv muaj nyob hauv cov khoom noj cog uas tuaj yeem hloov mus rau hauv cov tshuaj vitamin A. Muaj ntau dua 500 cov carotenoids paub. Ib qho xws li carotenoid yog beta-carotene.

Beta-carotene yog cov tshuaj antioxidant. Antioxidants tiv thaiv hlwb los ntawm kev puas tsuaj los ntawm cov tshuaj hu ua dawb radicals.

Dawb radicals ntseeg kom:

• Pab txhawb rau qee cov kab mob mus ntev
• Ua lub luag haujlwm ntawm kev laus

Noj cov zaub mov ntawm beta-carotene tuaj yeem txo qhov kev pheej hmoo ua mob cancer.

Cov tshuaj Beta-carotene tsis zoo li txo qis kev mob qog noj ntshav.

Vitamin A yog los ntawm cov tsiaj txhu, xws li cov qe, nqaij, mis uas muaj roj, cheese, qab zib, nplooj siab, raum, cod, thiab roj halibut.

Txawm li cas los xij, ntau yam ntawm cov peev txheej no, tsuas yog muaj Vitamin A muaj roj mis nyuj muaj roj ntau ntau hauv cov rog thiab roj cholesterol.

Qhov zoo tshaj plaws ntawm cov vitamin A yog:

• Cod daim siab cov roj
• Cov qe
• Fortified tshais cereals
• Fortified skim mis
• Cov txiv kab ntxwv thiab zaub daj thiab txiv hmab txiv ntoo
• Lwm qhov chaw ntawm beta-carotene xws li zaub cob pob, zaub ntsuab, thiab feem ntau tsaus ntsuab, nplooj zaub

Qhov ntau qhov tob xim cov txiv hmab txiv ntoo lossis zaub, qhov ntau dua cov nqi ntawm cov beta-carotene. Cov zaub ntsuab ntawm beta-carotene yog cov muaj roj- thiab tsis muaj roj cholesterol. Lawv txoj kev nqus tau zoo dua yog tias cov chaw no tau noj nrog cov rog.

TXHEEJ TXHEEM:

Yog tias koj tsis tau txais cov vitamin A txaus, koj muaj feem ntau qhov muag teeb meem xws li:

• Cov qhov muag tsis pom kev thaum hmo ntuj
• Cov mob puas tsuaj uas tsis thim rov qab los hu ua xerophthalmia

Tsis muaj cov vitamin A tuaj yeem ua rau hyperkeratosis lossis qhuav, ua tawv nqaij.

KEV RUAJ NTSEG:

Yog tias koj tau txais cov vitamin A ntau dhau, koj tuaj yeem ua rau mob.

• Ntau ntawm cov vitamin A kuj tseem tuaj yeem ua rau muaj lub hnub nyoog tsis xws luag.
• Yuav tsum siv tshuaj vitamin A lom feem ntau tshwm sim thaum ib tus neeg laus noj ntau pua txhiab IUs ntawm vitamin A.
• Ntev mus kuaj tshuaj vitamin A yuav tshwm sim rau cov neeg laus noj ntau dua 25,000 IU nyob rau ib hnub.

Cov menyuam mos thiab menyuam yaus yuav nkag siab zoo txog cov tshuaj vitamin A. Lawv tuaj yeem mob tau tom qab noj cov vitamin A lossis cov tshuaj vitamin ntau ntau xws li retinol (pom hauv cov tawv nqaij).

Cov ntau ntau ntawm beta-carotene yuav tsis ua rau koj muaj mob. Txawm li cas los xij, cov roj ntau ntawm beta-carotene tuaj yeem hloov daim tawv nqaij daj lossis txiv kab ntxwv. Cov xim tawv nqaij yuav rov zoo li qub thaum koj txo qis koj cov beta-carotene.

Txoj hauv kev zoo tshaj plaws kom tau txais cov kev xav tau niaj hnub ntawm cov vitamins tseem ceeb yog noj ntau yam txiv hmab txiv ntoo, zaub, zaub mov muaj mis, legumes (taum qhuav), lentils, thiab nplej.

Pawg Tswj Xyuas Khoom Noj thiab Khoom Noj ntawm Lub Tsev Kawm Txuj Ci Kev Noj Qab Haus Huv - Kev Nyuaj Siab Kev Nyuaj Siab (DRIs) Pom zoo kom nkag mus rau cov tib neeg muaj vitamin A:

Cov menyuam mos (nruab nrab qhov nqus)

• 0 txog 6 hlis: 400 micrograms ib hnub (mcg / hnub)
• 7 txog 12 hli: 500 mcg / hnub

Qhov Pom Zoo Noj Zaub Mov Noj (RDA) rau cov vitamins yog ntau npaum li cas ntawm txhua cov vitamins feem ntau cov neeg yuav tsum tau txais nyob rau ib hnub. RDA rau cov vitamins yuav siv los ua lub hom phiaj rau txhua tus neeg.

Cov menyuam yaus (RDA)

• 1 mus rau 3 xyoos: 300 mcg / hnub
• 4 txog 8 xyoo: 400 mcg / hnub
• 9 txog 13 xyoos: 600 mcg / hnub

Cov hluas thiab cov laus (RDA)

• Cov txiv neej hnub nyoog 14 thiab laus dua: 900 mcg / hnub
• Cov poj niam hnub nyoog 14 thiab laus dua: 700 mcg / hnub (rau cov poj niam hnub nyoog 19 txog 50, 770 mcg / hnub thaum cev xeeb tub thiab 1,300 mcg / hnub thaum pub niam mis)

Ntau npaum li cas ntawm cov vitamin koj xav tau yog nyob ntawm koj lub hnub nyoog thiab poj niam txiv neej. Lwm yam, xws li cev xeeb tub thiab koj li kev noj qab haus huv kuj tseem ceeb. Nug koj tus kws kho mob saib yam tshuaj twg zoo tshaj rau koj.

Retinol; Retinal; Retinoic acid; Carotenoids

• Kev pab cuam Vitamin A
• Vitamin A los

Mason JB. Cov vitamins, lw cov zaub mov, thiab lwm yam micronutrients. Hauv: Goldman L, Schafer AI, eds. Goldman-Cecil TshuajCov. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016: tshooj 218.

Ross CA. Vitamin A muaj qhov tsis txaus thiab tshaj. Hauv: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Phau Ntawv ntawm PediatricsCov. 21st ed. Philadelphia, PA: Elsevier; 2020: chap 61.

Salwen MJ. Cov vitamins thiab kab kawm. Hauv: McPherson RA, Pincus MR, eds. Henry's Kev Kuaj Mob thiab Kev Tswj Xyuas los ntawm Laboratory Txoj KevCov. 23rd ed. St Louis, MO: Elsevier; 2017: chap 26.

Yog li YT. Kev tiv thaiv kab mob tsis txaus ntawm cov hlab ntsha tsis sib haum. Hauv: Daroff RB, Jankovic J, Mazziotta JC, Pomeroy SL, eds. Bradley's Neurology nyob rau hauv Kev Soj NtsuamCov. 7 tus ed. Philadelphia, PA: Elsevier; 2016: chap 85.