Vitamini D ndi vitamini wambiri. Lilipo mu mitundu inayi yosiyana: cholecalciferol, calcifediol, calcitriol, ndi ergocalciferol.
Cholecalciferol: Fomu iyi imatchedwanso vitamini D3, ndipo imapangidwa kuchokera ku kolesterolini m'thupi mwathu pamene khungu lanu limatulukira kuwala kwa ultraviolet. Kwa ambiri a ife, zimatengera mphindi zisanu kapena 30 kutuluka kwa dzuwa masiku awiri sabata iliyonse kuti tikhale ndi vitamini D okwanira ngakhale kuti zimasiyana malinga ndi nyengo komanso nthawi.
Cholecalciferol sichigwira ntchito; iyenera kuyenda kudutsa m'magazi anu mpaka chiwindi kumene imasandulika kukhala mtundu wina wa vitamini D wotchedwa calcifediol.
Calcifediol: Vitamini D imatchedwa 25-hydroxyvitamin D kapena calcifediol. Ndilo mavitamini D omwe amayesedwa m'mayesero a magazi pamene wothandizira zaumoyo wanu akufuna kudziwa ngati muli ndi zizindikiro za kuchepa kwa vitamini D. Ngati ma calcidiol anu ali otsika, simungathe kupanga vitamini D okwanira, zomwe zingayambitse mafupa anu. Kwa ana, izi zimatchedwa rickets ndi akuluakulu, amatchedwa osteomalacia. Osteomalacia amatha kudwala matenda otupa mafupa.
Calcitriol: Impso zanu zimatenga calcifediol ndikuzisandutsa ku vitamini D yogwira ntchito yotchedwa 1,25-hydroxyvitamin D, kapena calcitriol. Mtundu wa vitamini Dwu umalimbikitsa kutentha kwa calcium komanso kumathandiza kuchepetsa magazi.
Iyenso ili ndi gawo mu kukula kwa maselo ndi mitsempha ndi minofu ntchito. Calcitriol imathandizanso kuti chitetezo cha mthupi chitetezeke komanso chingathandize kuchepetsa kutupa. Thupi lanu limayendetsa magulu anu a calcitriol mwachangu kwambiri, choncho si njira yabwino yoyesa kapena kuyang'anira kuchepa kwa vitamini D.
Ndipotu maseĊµera a calcitriol akhoza kukhala abwino pamene ma calcifediol amayamba kusiya.
Ergocalciferol: Vitamini D2, kapena ergocalciferol, ndi ofanana ndi cholecalciferol, koma ndi mawonekedwe a vitamini D opangidwa mu zomera. Chiwindi chanu chingasinthe ergocalciferol ku calcifediol. Sitikutembenuzidwa kukhala calcidiol moyenera monga cholecalciferol, koma zikuwoneka kuti ndi okwanira kuti mugwiritsire ntchito monga chakudya chowonjezera .
Kodi Vitamini D Ichokera Kuti?
Vitamini D sichipezeka m'makudya ambiri pokhapokha atakhala otetezedwa , monga mkaka, yogurt, mkaka wa soya ndi chakudya cham'mawa. Mavitamini D ang'onoang'ono amapezeka mu nsomba zonenepa komanso chiwindi cha ng'ombe.
Thupi lanu limapangitsa vitamini D pamene khungu lanu limapezeka kuwala kwa ultraviolet B (UVB) dzuwa. Pakadutsa mphindi 5 mpaka 30 khungu lanu pamaso, mikono, mmbuyo kapena miyendo (popanda kuwala kwa dzuwa) kawiri mlungu uliwonse ndikwanira.
Koma, kutentha kwambiri kwa dzuwa ndi chiopsezo cha khansara ya khungu, kotero muyenera kugwiritsa ntchito sunscreen patapita mphindi zochepa padzuwa, ngakhale kuti mulibe mitambo kapena mitambo.
Kuchuluka kwa kukhudzidwa kumadalanso nthawi ya chaka. Kumpoto kwa dziko lapansi, mazira a UVB amakhala oopsa kwambiri m'miyezi ya chilimwe komanso mochepa kwambiri m'nyengo yozizira. Ndipotu, ngati mukukhala kumpoto kwa digiri 42-degree, mudzakhala ndi nthawi yovuta kupeza kuwala kwa dzuwa kuyambira November mpaka February.
Onani mapu a North America. Ngati mumakhala kumpoto kwa mzere wochokera pamapu ochokera kumpoto kumpoto kwa California kupita ku Boston, Massachusetts, mwinamwake muyenera kupeza vitamini D ochuluka kuchokera ku zakudya zomwe mumadya (kapena kuchokera ku zowonjezeretsa) m'nyengo yozizira, ngakhale mutachita pitani kunja tsiku lirilonse.
Mphamvu ya kuwala kwa UVB imachepetsedwanso ndi mitambo ndi kuipitsidwa. Mazira a UVB sangayende kudzera mu galasi kotero kukhala pafupi ndi zenera sikukupatsani dzuwa lokwanira kuti likhale ndi vitamini D.
N'chifukwa Chiyani Mufunikira Vitamini D?
Thupi lanu limafuna vitamini D kuti imve ndi kugwiritsa ntchito calcium , yomwe imachititsa kuti mafupa ndi mano anu akhale olimba, ndipo ndizofunika kuti magazi azikhala ochepa komanso azigwira ntchito.
Kulephera kwa vitamini D kungatheke ngati simukupeza dzuwa, ngati impso zanu sizingasinthe mawonekedwe osungirako, kapena ngati simungatenge ma vitamini D chifukwa cha mavuto anu. Kulephera kwa vitamini D kumatengera mafupa ndi matenda ofooka omwe amatchedwa rickets ana ndi osteomalacia akuluakulu.
National Academy of Sciences, Engineering ndi Medicine, Health and Medicine Division imaika chakudya chamtundu uliwonse cha mavitamini ndi mchere. Ngakhale kuti kuwala kwa dzuwa kumayambira kwambiri, IOM yakhazikitsa tsiku lililonse chakudya cha vitamini D chomwe chimadalira zaka. N'chimodzimodzi kwa amuna ndi akazi.
Ma CDI amaimira ndalama zomwe munthu wathanzi amafunikira, choncho ngati muli ndi zovuta zaumoyo, muyenera kufunsira kwa wothandizira zaumoyo wanu.
Zolemba Zowonjezera Zakudya
- Kufikira zaka 70: 600 Zogwirizanitsa Mayiko (IUs) pa tsiku
- Zaka 71 kapena kupitirira: 800 UU pa tsiku
Kafukufuku wowonetsetsa amasonyeza kuti kukhala ndi vitamini D osakwanira kungagwirizane ndi chiopsezo cha khansa, multiple sclerosis, shuga ndi kuthamanga kwa magazi.
Koma mpaka tsopano, kutenga zowonjezerapo ndi lingaliro la kuchitira zinthu izi sizinapangidwe kuti ndi zopindulitsa.
Vitamini D zowonjezereka zingakhale zothandiza kwa anthu ena, makamaka m'nyengo yozizira kapena kwa iwo amene amapewa kutuluka dzuwa. Mungasankhe kuchokera ku mitundu iwiri, kaya vitamini D2 (ergocalciferol, mawonekedwe omwe amapezeka mu zomera) kapena vitamini D3 (cholecalciferol, mtundu umene umapezeka mwa nyama). Thupi lanu lingadye kwambiri vitamini D3 kuti D2, koma kafukufuku ambiri amasonyeza kuti mtundu uliwonse udzakupatseni vitamini D wokwanira ngati mutatsatira malangizo pa lemba kapena malangizo a dokotala wanu.
Kafukufuku wina wa 2017 anafufuza kugwiritsa ntchito madzi kapena ma coki olimbikitsidwa ndi mitundu iwiri ya vitamini D kuti amayi omwe anapatsidwa D3 mawonekedwe a masabata khumi ndi awiri amakhala ndi mavitamini D opitirira magazi poyerekeza ndi amayi omwe adatenga D2, ndizofunika kuti musinthe zotsatila zamakono.
Kutenga mavitamini akuluakulu a mavitamini D kwa nthawi yaitali kungayambitse vitamini D, kotero Institute of Medicine inatsimikiza kuti ndi yotheka. Kugwiritsa ntchito mlingo wa nthawi yayitali pamtundu uwu kungapangitse ziwerengero za minofu zomwe zingapangitse kuwonongeka kwa mtima, mitsempha ya magazi, ndi impso. Osagwiritsa ntchito mlingo waukulu wa vitamini D zowonjezereka popanda kulankhula ndi dokotala poyamba.
Zolembera Zokwera Zosalekeza
- Mibadwo 1-3: 2500 UU pa tsiku
- Mibadwo 4-8: 3000 UU pa tsiku
- Mibadwo 9 ndi pamwamba: 4,000 UU pa tsiku
Vitamini D poizoni sichichokera ku vitamini D yomwe thupi lanu limapanga pamene khungu lanu likuwonekera ku dzuwa.
> Zotsatira:
> Tripkovic L, Wilson LR, Hart K, Johnsen S, de Lusignan S, et.al. "Mavitamini tsiku lililonse ndi 15 mg vitamini D2 poyerekeza ndi vitamini D3 kuonjezera nyengo yachisanu 25-hydroxyvitamin D m'dera labwino la South Asia ndi azungu a ku Ulaya: chidziwitso cha zakudya chokhazikitsa chakudya cha 12-wk. Am J Clin Nutr. 2017 Jul 5. pii: ajcn138693. do: 10.3945 / ajcn.116.138693.
> National Academy of Sciences, Engineering ndi Medicine, Health ndi Medicine Division. "Zolemba Zowonjezera Zakudya Zakudya ndi Machitidwe."
> Ma Institutes of Health, Office of Food Supplements. "Vitamini D - Zapangidwe Za Zaumoyo."