I-Vitamin D iyinvithamini enamafutha anamunwe. Kukhona izinhlobo ezine ezahlukene: i-cholecalciferol, i-calcifediol, i-calcitriol, ne-ergocalciferol.
I-Cholecalciferol: Le fomu ibizwa nangokuthi i-vitamin D3, futhi yenziwa nge-cholesterol emzimbeni wakho lapho isikhumba sakho sibonakala ekukhanyeni kwe-ultraviolet. Kwabaningi bethu, kuthatha imizuzu engama-5 kuya kwezingama-30 ukushiswa kwelanga izinsuku ezimbili ngesonto ukwenza inani elanele levithamini D nakuba lihluka ngokuya kwezimo zezulu nesikhathi sonyaka.
I-Cholecalciferol ayisebenzisi ngokwanele; kufanele uhambe ngegazi lakho embindi lapho liguqulwa khona libe uhlobo oluthile lwevithamini D olubizwa ngokuthi i-calcifediol.
I-Calcifediol: Ifomu lokugcina levithamini D libizwa ngokuthi i-25-hydroxyvitamin D noma i-calcifediol. Kubuye kube uhlobo lwevithamini D olulinganiselwa ekuhlolweni kwegazi uma umhlinzeki wakho wezempilo efuna ukunquma uma unesifo se-vitamin D. Uma amazinga akho e-calcidiol ephansi, ungase ungenzi vithamini D ngokwanele, okungaholela ekunciphiseni nasekubuthakeni kwamathambo akho. Ezinganeni, lokhu kuthiwa ama-rickets kanye nabantu abadala, kuthiwa i-osteomalacia. I-osteomalacia ingabangela ukuguqulwa kwamathambo.
I-Calcitriol: Izinso zakho zithatha i-calcifediol futhi ziyiguqulela kwifomu esebenzayo ye-vitamin D ebizwa ngokuthi i-1,25-hydroxyvitamin D, noma i-calcitriol. Lolu hlobo lwe-vitamin D lukhuthaza ukuxiliswa kwe- calcium futhi kusiza ukulinganisa amazinga egazi.
Ibuye inendima ekukhuleni kwamaselula okujwayelekile kanye nomsebenzi wesisindo nomisipha. I-Calcitriol nayo iyadingeka ukuze isistimu ye-immune enempilo futhi ingasiza ukunciphisa ukuvuvukala. Umzimba wakho ulawula amazinga egazi lakho nge-calcitriol ngokucophelela, ngakho akuyona ifomu elifanele lokuhlola noma lokuqapha ukutholakala kwevithamini D.
Eqinisweni, amazinga e-calcitriol angase ahlale evamile ngenkathi amazinga e-calcifediol eqala ukwehla.
I-Ergocalciferol: I- Vitamin D2, noma i-ergocalciferol, ifana ne-cholecalciferol, kodwa uhlobo lwevithamini D olwenziwe ngezitshalo. Isibindi sakho singaguqula i-ergocalciferol ku-calcifediol. Awuguqulwa ku-calcidiol ngendlela ephumelelayo njenge-cholecalciferol, kodwa kubonakala sengathi yanele ukuyisebenzisa njengokwengeza kokudla .
Uphi I-Vitamin D Evela Kuyo?
I-Vitamin D ayitholakali ekudleni okuningi ngaphandle kokuthi iqinisekiswe , njengobisi, i-yogurt, ubisi lwe-soy kanye namabele okusasa kwasekuseni. Amancane amavithamini D atholakala enhlanzi enamafutha nenyama yesilwane.
Umzimba wakho wenza i-vitamin D lapho isikhumba sakho sibonakala emisebeni ye-ultraviolet B (UVB) emini. Emaminithini angaba ngu-5 kuya kwangu-30 okuvezwa esikhumba ebusweni bakho, izingalo, emuva noma imilenze (ngaphandle kwesihenqo selanga) izikhathi ezimbili ngesonto lanele.
Kodwa, ukukhanya kakhulu kwelanga kuyingozi engozini yomdlavuza wesikhumba, ngakho-ke kufanele usebenzise i-sunscreen ngemva kwemizuzu embalwa elangeni, ngisho nasezinsukwini ezinzima noma ezinamafu.
Inani lokuchayeka lixhomeke nesikhathi sonyaka. Enyakatho ye-hemisphere, imisebe ye-UVB ikhulu kakhulu ezinyangeni zasehlobo futhi ingabi namandla phakathi nezinyanga zasebusika. Eqinisweni, uma uhlala enyakatho ye-42-degree latitude, uzoba nesikhathi esinzima ukuthola ukukhanya kwelanga okwanele kusukela ngoNovemba kuya kuFebhuwari.
Bonisa imephu yaseNyakatho Melika. Uma uhlala enyakatho komugqa odwetshwe ebalazweni osuka emngceleni osenyakatho weCalifornia ukuya eBoston, eMassachusetts, cishe uzodinga ukuthola u-vithamini D ngaphezulu kokudla okudlayo (noma okuvela ezithebeni) phakathi nezinyanga zasebusika, ngisho noma wenza hamba ngaphandle nsuku zonke.
Ukuqina kwemisebe ye-UVB kuncishiswe ngamafu nokungcola. Imibala ye-UVB ngeke ihambe ngeklasi ukuze uhlale eduze kwefasitela ngeke ikunike ilanga elanele lokwenza i-vitamin D.
Kungani Udinga I-Vitamin D?
Umzimbeni wakho udinga i-vitamin D ukuze ubambe futhi isebenzise i- calcium , egcina amathambo akho namazinyo akho eqinile, futhi kubalulekile ekuvaleni kwegazi okujwayelekile nokusebenza komzimba.
Ukuntuleka kwe-vitamin D kungenzeka uma ungatholi ukukhanya kwelanga elanele, uma izinso zakho zingenakuguqula ifomu lokugcina kufomu elisebenzayo, noma uma ungakwazi ukumbamba i-vitamin D ngenxa yezinkinga zesistimu yakho yokugaya. Ukuntuleka okungavamile kwamavithamini D kuholela emathanjeni nasezifo ezibuthakathaka ezibizwa ngokuthi i-rickets ezinganeni kanye ne-osteomalacia kubantu abadala.
I-National Academy of Sciences, Engineering and Medicine, Health and Medicine Division ibeka zonke izindlela zokudla eziphathelene namavithamini namaminerali. Nakuba ukukhanya kwelanga kungumthombo oyinhloko, i-IOM ibeke imfuneko yansuku zonke yevithamini D yokudla esekelwe eminyakeni yobudala. Kufana nalabo abesilisa nabesifazane.
La ma-DRI amelela inani elidingwa ngumuntu onempilo, ngakho-ke uma unenkinga yezempilo, kufanele uthintane nomhlinzeki wakho wokunakekela impilo.
Izindleko zokudluliswa kwezidakamizwa
- Kuze kube iminyaka engu-70: 600 Izinyunyana Zomhlaba Wonke (IUs) ngosuku
- Iminyaka engu-71 nangaphezulu: ama-IU angu-800 ngosuku
Ucwaningo lwe-Observational lubonisa ukuthi ukuba namavithamini D anganele ngokwanele kungase kuhlotshaniswe nengozi enkulu yomdlavuza, multiple sclerosis, isifo sikashukela kanye nokucindezelwa kwegazi eliphezulu.
Kodwa kuze kube manje, ukuthatha izithako nomqondo wokuphatha lezi zimo akubonwanga ukuthi kuzuzisa.
Izithako ze-Vitamin D zingase zibe usizo kwabanye abantu, ikakhulukazi ebusika noma kulabo abavame ukugwema ukushisa kwelanga. Ungakhetha kusuka kumafomu amabili, noma i-vitamin D2 (ergocalciferol, ifomu etholakala ezitshalweni) noma i-vitamin D3 (cholecalciferol, uhlobo olutholakala ezilwaneni). Umzimba wakho ungathatha i-vitamin D3 kancane kangcono ukuthi i-D2, kodwa ucwaningo oluningi lubonisa ukuthi uhlobo olulodwa luzokunika uvithamini D ngokwanele uma ulandela izinkomba zelebula noma iseluleko esivela kudokotela wakho.
Ucwaningo olulodwa luka-2017 oluhlolisise ukusetshenziswa kwamanzi noma amakhukhi aqinisekiswe ngamafomu amabili kavithamini D atholakala ukuthi abesifazane abanikezwa i-D3 ifomu lamaviki angu-12 babevame ukuba namazinga aphezulu egazini ka-vitamin D uma kuqhathaniswa nabesifazane ababethathile i-D2, noma kunjalo kuyadingeka ukwenza noma yiziphi izinguquko ezinconyweni zamanje.
Ukuthatha ama-vitamin D amaningi isikhathi eside kungase kubangele ukungcola kwe-vitamin D, ngakho-ke i-Institute of Medicine inqume amazinga aphezulu angenakubekezeleka. Ukusebenzisa isikhathi esiningi isikhathi esingaphezu kwalezi zimali kungabangela izibalo zamathisimu ezingabangela ukulimala enhliziyweni, imithwalo yegazi, nezinso. Ungasebenzisi ama-vitamin D amaningi ngaphandle kokukhuluma nodokotela wakho kuqala.
Izilinganiso ezingaphezulu ezingapheli
- Iminyaka 1-3: 2500 IUs ngosuku
- Iminyaka engu-4-8: 3000 IUs ngosuku
- Iminyaka engu-9 nangaphezulu: ama- IU angu-4 000 ngosuku
I-Vitamin D yobuthi ngeke ivela ku-vitamin D eyenziwa umzimba wakho lapho isikhumba sakho sibonakala elangeni.
> Imithombo:
> Tripkovic L, Wilson LR, Hart K, Johnsen S, de Lusignan S, et.al. "Ukwengezwa kwansuku zonke nge-15 μg vitamin D2 uma kuqhathaniswa ne-vitamin D3 ukwandisa isikhathi sasebusika isimo sama-25-hydroxyvitamin D emazweni aseNingizimu Afrika asempilweni aseNingizimu Afrika nabomhlophe abamhlophe: ukuhlolwa kwe-food-fortification e-randomised-12-wk." I-Am J Clin Nutr. 2017 Julayi 5. pii: ajcn138693. doi: 10.3945 / ajcn.116.138693.
> National Academy of Sciences, Engineering and Medicine, Health and Medicine Division. "Ukudluliswa Kwezinkuni Kufaka Amathebula Ne-App."
> Izikhungo Zempilo Zesizwe, iHhovisi Lokudla Kwezondlo. "I-Vitamin D - I-Health Professional Fact Sheet."