UBrian Walsh
Cishe bonke ochwepheshe bayayincoma. Futhi wonke umuntu uyakwamukela. Kodwa kuthiwani uma siyisebenzisa? Kuthiwani uma izithasiselo zethu zikavithamini D zingasisizi ngalutho?
Kungani sintula amavithamini?
Ucwaningo lweminyaka embalwa edlule luye lwabonisa ukuthi ingxenye enkulu yabantu emhlabeni ine-vitamin D. Nokho, impendulo yombuzo wezizathu zalesi simo ibonakala iyinqaba.
Abahlinzeki bezempilo ngokuvamile bahlola amazinga kavithamini D eziguli futhi baqaphele ukuthi aphansi. Bese benikeza izithasiselo. Isiguli sibuya ezinyangeni ezimbalwa kamuva futhi izinga likavithamini D lisephansi. Bese udokotela andisa izithasiselo. Kule minyaka eyishumi edlule, i-vitamin D isiphenduke into eyisithako esiyisimangaliso, efundwa kakhulu kunanoma yimuphi omunye uvithamini ekhulwini lama-21.
Amakhulu ocwaningo lwesayensi abonisa ukuthi uvithamini D ungasiza ekuvimbeleni izifo ezisukela ku-osteoporosis kanye nezifo ezizimele zokuzivikela ezifweni zenhliziyo nemithambo yegazi nomdlavuza. Kuthinta izinqubo zokuvuselela umzimba, kanye nezakhi zethu zofuzo. Abanye baze basikisela ukuthi ukuntula uvithamini D kungaholela ekukhuluphaleni ngokweqile. Khonamanjalo, izibalo zibonisa ukuthi u-40-50% wabantu abadala abanempilo kanye nezingane abanawo uvithamini D.
Eqinisweni, eminyakeni embalwa edlule kuye kwaba nokwanda emhlabeni wonke kwama-rickets, futhi ukuntuleka kukavithamini D kuvame ukutholakala ezinganeni ezingondlekile—ngisho nasemazweni anezimboni!
Izindaba ezinhle ukuthi ochwepheshe bezokunakekelwa kwempilo bayalwazi lolu cwaningo kanye nezingozi ezihlobene namazinga aphansi kavithamini D. Odokotela abaningi bajwayele ukunikeza imithamo ephezulu yezithako zamavithamini, 2000-10000 IU (Amayunithi Omhlaba Wonke) ngosuku, kufika ku-50 IU ngesonto, futhi ngezinye izikhathi nangaphezulu. .
I-Vitamin D ngokusobala isekela impilo yomuntu. Kodwa kungani singaxazululi izizathu eziyisisekelo zokuthi kungani amazinga ethu kavithamini D ehla njalo? Futhi iphephe kangakanani i-vitamin D yesikhathi eside, empeleni? Iyini i-vitamin D futhi isebenza kanjani?
Igama elithi "vitamin D" libhekisela eqenjini lezinhlanganisela ezincibilikayo ezisebenza njengama-prehormones, ama-hormone precursors, futhi uhlobo olusebenzayo lwevithamini D lubizwa ngokuthi i-calcitriol.
Phakathi kwezinhlobo zikavithamini D ezaziwa kakhulu uvithamini D3 (i-cholecalciferol), otholakala ezinhlanzini, ezikhipheni zamaqanda, noshizi, futhi wahlanganiswa esikhumbeni sabantu nezilwane. Olunye uhlobo oluvamile, i-vitamin D2 (ergocalciferol), ihlanganiswa yisikhunta futhi ivame ukusetshenziselwa ukuqinisa ukudla okufana nobisi. Sikhiqiza uvithamini D esikhumbeni sethu lapho siphuma elangeni - ikakhulukazi, lapho isikhumba sethu sichayeka emisebeni ye-ultraviolet. Lolu hlobo lokuqala lukavithamini D lubizwa nge-7-dehydrocholesterol futhi luthunyelwa esibindini lapho luguqulwa lube olunye, uhlobo olusebenza kancane lukavithamini D olubizwa ngokuthi i-25-hydroxyvitamin D. Lolu uhlobo lwevithamini oluhlolwa odokotela lapho bebheka. ngenxa yokuntula.
Lapho uvithamini D ephuma esibindini, uya ezinso, lapho eguqulwa abe uhlobo olusebenza kakhulu lukavithamini D olubizwa ngokuthi i-calcitriol, noma i-1,25 dihydroxyvitamin D. Leli fomu alisabhekwa njengevithamini, kodwa kunalokho libhekwa njengehomoni ye-steroid. (Ungase ujwayele amanye amahomoni e-steroid afana ne-estrogen, testosterone, ne-cortisol.)
Indima ye-vitamin D emzimbeni
Njengoba igama lefomu elisebenzayo likavithamini D libonisa, i-calcitriol isiza ekumunceni i-calcium namanye amaminerali emzimbeni wethu. I-Calcitriol inyusa ukumuncwa kwe-calcium ekudleni emgudwini wethu wokugaya ukudla.
Uma sidinga i-calcium eningi, izinso zethu zingakhiqiza okwengeziwe kohlobo olusebenzayo lwevithamini D, okuphakamisa amazinga e-calcium yethu ngokwandisa inani esilimunca ekudleni kwethu.
Kuze kube muva nje, izitho ezimbalwa kuphela emizimbeni yethu ebezicatshangwa ukuthi zinama-receptor e-vitamin D, abizwa ngokuthi ama-varistors. Kodwa-ke, ucwaningo lwakamuva lubonisa ukuthi cishe wonke amangqamuzana emzimbeni wethu anama-receptors e-vitamin D, okubonisa indima ebaluleke kakhulu yale vithamini kunalokho esasikucabanga ngaphambili.
Lolu lwazi olusha lusisizile ukuthi sithole ukuthi uvithamini D uthinta namasosha omzimba futhi usiza ekwehlukaniseni amaseli, ukulawula umfutho wegazi, ukukhiqizwa kwe-insulin, nokunye.
Lokhu kusibuyisela embuzweni wethu wokuqala: kusho ukuthini ukuntula uvithamini D? Kuvele ukuthi lokhu kuwuphawu - ngomqondo obanzi - ukuthi mhlawumbe kukhona okungahambanga kahle ezinqubweni zethu zomzimba.
I-Vitamin D Debate
I-25-hydroxyvitamin D, uhlobo lwevithamini D, ikhiqizwa ikakhulukazi isibindi futhi ngokuvamile yamukelwa njengomaka othembeke kakhulu wokuhlola amazinga kavithamini D. Kodwa-ke, ososayensi abakwazi ngisho ukuvumelana ngohlu olufanele lwamazinga kavithamini D.
Ukushoda kwe-Vitamin D kwaziwa ukuthi kuholela ekuphambeni kwamathambo njengama-rickets kanye ne-osteomalacia lapho amazinga egazi engaphansi kuka-25 ng/mL. Abanye abacwaningi bakholelwa ukuthi ibanga elilunge kakhulu liphakathi kuka-50 - 80 ng/mL. Kodwa akukho ukuvumelana ngalolu daba.
Ngo-2010, i-National Institutes of Health (USA) yabeka ukudla okunconyiwe kwe-vitamin D ku-600 IU nsuku zonke ezinganeni, izingane, kanye nabantu abadala abafika eminyakeni engu-70. Lokhu kungaphezu kwesincomo sangaphambilini se-200 IU ngosuku. Nakuba lokhu kwanda kungase kubonakale kubalulekile, abanye abantu baphikisa ngokuthi akukukhulu ngokwanele ukuba kube nemiphumela yezempilo “eyinhlekelele”.
Izinsuku ezinelanga… noma cha?
NgokweNational Institutes of Health, singahlangabezana kalula nesidingo somzimba wethu sikavithamini D ngokuthola ukukhanya kwelanga okwanele. Uma u-30% wesikhumba sethu sivezwa (okungukuthi singagqoki noma singasikhiphile ilanga) sibe siselangeni imizuzu emihlanu kuya kwengamashumi amathathu phakathi kuka-10 ekuseni no-3 ntambama kathathu ngesonto, kwanele lokho.
Kodwa uma kubhekwa inani labantu abahlushwa amazinga aphansi kavithamini D - ngisho nasezindaweni ezinelanga elishisayo - kufanele uzibuze ukuthi lesi sincomo sinembile yini. Kithina esihlala enyakatho ye-49th parallel, ake sithi ngeke sidalule u-30% wesikhumba sethu esingavikelekile elangeni kaningi ebusika.
Uma amazinga akho ephansi, ingabe kufanele udle izithasiselo?
Kuyacaca ukuthi uvithamini D udlala izindima eziningi ezibalulekile emzimbeni nokuthi ukuntuleka kukavithamini D kungakulimaza. Olunye ucwaningo lubonisa ukuthi ukuncipha kwezinga likavithamini D, kwandisa ingozi yokufa kwezimbangela.
Ngakolunye uhlangothi, ucwaningo lubonisa nokuthi ingozi yokufa okuphelele ikhuphuka ngokushesha nje lapho amazinga kavithamini D edlula ama-40 ng/mL. Futhi, ngokuvamile, asinabo ubufakazi besayensi obungangabazeki bokuphepha kwesikhathi eside kwemithamo ephezulu kavithamini D. Mhlawumbe ngaphambi kokuthi siqale ukugwinya amaphilisi amaningi, kufanele sihlole ukuthi siyakwenza yini. Phela, isayensi yezokwelapha ivame ukuba nephutha.
Ukuze siqonde kangcono le ndaba, ake sibheke ubudlelwano obubalulekile phakathi kukavithamini D nezinye izakhi ezibalulekile.
I-Vitamin D ne-calcium
Enye yezingozi ezingaba khona zokuthatha uvithamini D kakhulu ukukhula kwe-hypercalcemia, noma amazinga aphezulu e-calcium egazini. I-Vitamin D ibulala amagundane. I-rodenticide iwumthamo onobuthi kavithamini D—okwanele ukubulala isilwane. Kodwa-ke, i-hypercalcemia ayivamisile ukuvela ngaphandle kwemithamo eyeqile kavithamini D, emzimbeni womuntu ingaba ndawana-thile ku-30,000-40,000 IU nsuku zonke. Abantu abaningi abathatha izithako ze-vitamin D abathathi kangako.
Nokho, lokhu akusho ngempela ukuthi umthamo othathiwe uphephile. Amazinga e-calcium emzimbeni alawulwa ngokuqinile kangangokuthi ukungavamile akubonakali njalo ekuhlolweni kwe-serum yegazi. Kodwa bangavela ngezinye izindlela. Omunye umphumela kungaba i-hypercalciuria, eyaziwa nangokuthi amatshe ezinso ze-calcium.
I-Hypercalciuria yenzeka lapho umzimba uzama ukukhipha i-calcium eningi futhi uyikhiphe ngezinso. Ngokusekelwe kulokhu okutholakele, abanye abacwaningi bakholelwa ukuthi amazinga aphezulu e-vitamin D eyengeziwe angase aholele ekwakhekeni kwamatshe ezinso.
Ngempela, ucwaningo olulodwa lwathola ukuthi izakhamuzi zasemakhaya asebekhulile ezithatha i-5000 IU kavithamini D nsuku zonke izinyanga eziyisithupha zibonise ukwanda kwe-urinary calcium ratio, i-creatinine. Kucatshangelwa ukuthi i-calcium eyeqile yakhishwa emchamweni, mhlawumbe ngenxa yokuthi ibiningi kakhulu emizimbeni yabo.
Ngakolunye uhlangothi, olunye ucwaningo lwakamuva lwathola ukuthi phakathi kwalabo amazinga kavithamini D asukela ku-20 kuya ku-100 ng/mL, kwakungekho mehluko lapho kwenzeka khona amatshe ezinso. Ngakho, isinqumo asicacile. Kodwa amatshe ezinso akuyona ukuphela kwengozi ye-calcium eningi.
Uma umzimba ungakwazi ukulawula amazinga e-calcium, imineral ingafaka izicubu ezithambile zomzimba, kuhlanganise nemithambo. Futhi, ngeshwa, olunye ucwaningo luphakamisa ukuthi lokhu kungenzeka ngempela lapho amazinga kavithamini D eba phezulu kakhulu.
Ucwaningo oluthathu ikakhulukazi luye lwabonisa ukwanda kwe-arterial calcification ezilwaneni eziphakelwa izithasiselo zikavithamini D. Futhi olunye ucwaningo lubonisa ukuthi amanani aphezulu kavithamini D angalimaza nesistimu yenhliziyo yomuntu.
Uyazi ukuthi imithamo ephezulu kavithamini D ingakhuphula inani le-calcium ezicutshini ezithambile zomzimba (njengemithambo), ngakho-ke kufanele uthathe ukwesekwa ngokungathi sína.
Ikakhulukazi uma kubhekwa ukwanda kwesifo senhliziyo nemithambo yegazi emphakathini wethu. Ngakho-ke, manje, ungase ulungele ukuphonsa uvithamini D wakho emgqonyeni kadoti. Kodwa ngaphambi kokuthi senze lokho, futhi, kudingeka sicabangele ngempela ukuthi kungani amazinga ethu kavithamini D ebonakala enganele kangangokuthi sivame ukuthatha izithasiselo. Khumbula ukuthi i-vitamin D ne-calcium kuhlangana ngokulingana okubucayi.
Ngakho-ke mhlawumbe amazinga kavithamini D aphansi ngenxa ye-calcium eningi? Futhi umzimba ucindezela ukukhiqizwa kwe-vitamin D nokuguqulwa ukuze kuncishiswe ukwanda okwengeziwe kwe-calcium. Kungani amazinga e-calcium ethu engase abe phezulu kakhulu? Amathuba ahlanganisa ukushoda kwe-magnesium, ukuntula amaprotheni, ukungasebenzi kahle kwesibindi, nokunye. Ake sibheke okunye ukusebenzelana okungenzeka.
I-Vitamin D ne-Vitamin K
Igama elithi vitamin K livela egameni lesiJalimane elithi koagulation. I-coagulation ibhekisela ohlelweni lokwakhiwa kwehlule legazi. Lokhu kufanele kukubonise ukuthi uvithamini K udlala indima ebalulekile enqubweni yokujiyisa igazi. Kalula nje, uvithamini K uvumela umzimba ukuba usebenzise i-calcium ukuze wenze umsebenzi wawo wokujiyisa. Uma i-vitamin K inganele, umzimba awukwazi ukusebenzisa i-calcium ukwakha ihlule.
Ngaphezu kokubamba iqhaza enqubweni yokujiyisa, uvithamini K usiza futhi ukwakha nokugcina amathambo namazinyo ethu. Lokhu ikwenza ngokuvula iphrotheni ethile ebizwa ngokuthi i-osteocalcin, esiza umzimba ukuthi usebenzise i-calcium.
Ngamanye amazwi, inhlanganisela ye-calcium ne-vitamin K isiza umzimba ukusebenzisa i-calcium ngendlela efanele. Futhi uma sintula kuvithamini K, i-calcium inganqwabelana ezicutshini zethu ezithambile.
Abantu abanamazinga aphansi kavithamini K bahlushwa i-atherosclerosis, ukubalwa kwemithambo yegazi. Futhi labo abadla u-vitamin K omningi (ikakhulukazi uvithamini K2) abathambekele kakhulu ekubalweni kwemithambo.
Ngempela, ucwaningo lwamagundane lubonise ukuthi ukuxhaswa kwe-vitamin K2 (kodwa hhayi i-K1) akuvimbeli nje kuphela ukubala kwe-arterial, kungase futhi kususe i-30-50% ye-calcium esivele ihlezi emithanjeni. Ngeshwa, lo mphumela womlingo awukakahlolwa kubantu kuze kube manje. Ngethemba ukuthi manje niyawubona umdanso ocashile owenzeka ngaphakathi kithina. I-Vitamin D inyusa izinga le-calcium emzimbeni. I-Vitamin K isiza umzimba ukusebenzisa i-calcium. Ngakho uma sithatha imithamo emikhulu kavithamini D lapho kukhona ukushoda kwevithamini K, imiphumela yesikhathi eside ingaba yinhlekelele.
I-Vitamin D ne-magnesium
I-Magnesium iyiminerali ebalulekile ebandakanyeka ezinqubweni ezihlukene ezingaphezu kuka-300 emzimbeni, kuhlanganise nekhono lokuthatha nokusebenzisa amandla. I-Magnesium ihlotshaniswa nokukhiqizwa nokusetshenziswa kwe-vitamin D. Ikakhulukazi, i-magnesium iyakwazi ukuguqula ukuzwela kwezicubu zethu kuvithamini D.
Kodwa okubaluleke kakhulu, kusiza nokugcina ibhalansi ye-calcium. Okungenani ingxenye yabantu abayidli inani elinconyiwe le-magnesium. Lokhu kungase kube ngenxa yokuthi okuqukethwe kwe-magnesium emhlabathini kwehle kakhulu eminyakeni engu-50 edlule, okwenza kube nzima ngokwengeziwe ukuhlangabezana nezidingo zethu.
Ngenxa yokuthi i-magnesium isetshenziswa ku-vitamin D metabolism, abanye abacwaningi bakholelwa ukuthi ukugcwalisa ngenani elikhulu likavithamini D kungase kuholele ekuntulekeni okwengeziwe kwe-magnesium. Kuyathakazelisa ukuthi ucwaningo lwakamuva lubonise ukuhlobana okuqinile phakathi kokuntuleka kwe-magnesium ne-vitamin D.
Lolu cwaningo lwathola ukuthi ukuthatha i-magnesium ngezithako ze-vitamin D kwaphumelela kakhulu ekulungiseni ukuntula kwe-vitamin D kunokuthatha u-vitamin D yedwa. Ngokumane ukhulise ukudla kwakho kwe-magnesium, unganciphisa ukufa okuhlobene nokushoda kwe-vitamin D-ngaphandle kokuthatha noma yiziphi izithako ze-vitamin D. uvithamini D
Kodwa, ngaphezu kokuxhumana kwe-vitamin D ne-magnesium, kukhona ubudlelwano be-magnesium ne-calcium. Futhi ngandlela thile, lawa maminerali amabili anemiphumela ephambene. Isibonelo, i-calcium ivuselela ukufinyela kwemisipha, kuyilapho i-magnesium ikhuthaza ukuphumula kwemisipha. I-calcium inyusa umsebenzi weplatelet kanye nokujiya kwegazi, kuyilapho i-magnesium iwavimbela.
Ngokuphambene nenkolelo evamile, amazinga angawodwa eyodwa yalawa amaminerali angase angabalulekile kunebhalansi phakathi kwawo. Ukweqile kwe-calcium kanye nokuntuleka kwe-magnesium kungabangela izinkinga ezinjengokwanda kwe-calcium efakwa emithanjeni. Phakathi naleso sikhathi, i-magnesium ingavimbela ukubalwa kwe-arterial.
Kodwa kwenzekani uma ungenayo i-magnesium futhi unquma ukuthatha uvithamini D? Kungaba nemiphumela eminingi engemihle, okuhlanganisa—ukuqagele—i-calcium efakwa emithanjeni.
I-Vitamin D kanye ne-Vitamin A
Ngaphezu kokusebenzelana okumnene ne-calcium ne-vitamin K, uvithamini D ubuye abe nobudlelwane novithamini A emizimbeni yethu. Igama elithi “vitamin” libhekisela eqenjini lezinhlanganisela ezincibilika emafutheni ezikhuthaza ukukhula nokuthuthuka, ukuzala, ukusebenza kwamasosha omzimba, ukubona, impilo yesikhumba, nokubonakaliswa kwezakhi zofuzo. Ngenxa yokuthi amavithamini ancibilikayo amafutha angagcinwa emzimbeni, angafinyelela emazingeni anobuthi.
Futhi nakhu okuthakazelisayo: kuvela ukuthi i-vitamin A ingavimbela imiphumela enobuthi ye-vitamin D, futhi ngokuphambene nalokho. Lokhu kusho ukuthi uma untula uvithamini A, amanani aphezulu kavithamini D angabangela izinkinga.
Phakathi naleso sikhathi, olunye ucwaningo lubonisa ukuthi ukwanda kukavithamini A kungase kunciphise ukunqwabelana kwe-calcium evame ukuhambisana namazinga aphezulu kavithamini D. Ingase futhi ivikele ekubalweni kwe-pathological ngenxa yobuningi bevithamini D.
Njengamanje, kusobala ukuthi kufanele siqaphele ngemithamo ephezulu kavithamini D. Abantu abangafika ku-35% abanawo uvithamini K. Olunye ucwaningo lubonisa ukuthi izithasiselo zikavithamini D zingase zibe nomthelela ekuntulekeni kukavithamini K, ukuncipha kwamathambo, nokuthamba. ukubalwa kwezicubu.
Abacwaningi batusa ukuthatha amavithamini A no-K ngesikhathi esifanayo ne-vitamin D ukuze kuthuthukiswe umphumela wokwelapha we-vitamin D futhi kunciphise imiphumela yayo engathandeki engase ibe khona.
Okukhathaza kakhulu kulokhu umphumela wevithamini D eyeqile ekubalweni kwenhliziyo nemithambo yegazi. Isifo senhliziyo kakade sesingumbulali ohamba phambili emazweni anezimboni. Akufanele siyibhebhethekise le nkinga.
Thatha I-Vitamin D Ngokuqapha
Sicabanga ukuthi sazi okuningi ngomzimba womuntu, kodwa asazi okuningi. Futhi uma kuziwa ku-physiology yomuntu kanye ne-biochemistry, kanye nendima umsoco kanye nezakhi zomuntu ngamunye ezidlalayo emizimbeni yethu, sazi okuncane nakakhulu.
Ukuntuleka kwevithamini D kuyisenzakalo sangempela futhi kuyingozi yangempela yezempilo, ngakho-ke kudingeka siqiniseke ukuthi sithola okwanele kwalesi sakhi esibalulekile.
Ngesikhathi esifanayo, kufanele futhi:
hlola imiphumela yesikhathi eside engaba khona yemithamo ephezulu yevithamini D; cabangela indima yezinye izakhi ezibalulekile ezisebenzisana novithamini D;
bheka njalo izimbangela zanoma yiziphi izimpawu nokushoda.
Yini okufanele siyenze?
1. Thola uvithamini D owanele, kodwa hhayi kakhulu.
Thatha cishe u-1000 IU ngosuku, kodwa ungadluli ku-2000 IU ngosuku phakathi nezinyanga zasebusika lapho ungakutholi ukukhanya kwelanga okwanele. Kuphephile, ikakhulukazi uma kufakwe ezinye izakhamzimba ezibalulekile, njengovithamini K, uvithamini A, ne-magnesium. Ungaqiniseka ukuthi uwathola ngokwanele ngokuthatha i-multivitamin.
Gwema ukweqisa izidakamizwa. Nakuba kusobala ukuthi isincomo sangaphambilini se-200 IU ngosuku cishe siphansi kakhulu, kusalindwe ucwaningo oluqinile mayelana nezinzuzo zesikhathi eside zemithamo ephezulu yevithamini D, qaphela ukudla kakhulu.
Yebo, akulona uhlelo oluphelele, ikakhulukazi phakathi nezinyanga zasebusika. Kodwa ukukhanya kwelanga kuseyindlela engcono kakhulu yokuba imizimba yethu ithole uvithamini D.
2. Sekela uVithamini D
Qaphela ukuthi ezinye izakhamzimba zisebenzisana novithamini D. Yidla ukudla okunhlobonhlobo okugaywe kancane ukuze uthole i-magnesium, uvithamini A, novithamini K.
Yidla imifino kanye nokudla okuvutshiwe. I-Kale, isipinashi, ne-chard imithombo emihle kavithamini K1. Bacebile futhi nge-magnesium. I-sauerkraut kanye noshizi ovutshiwe yimithombo emihle kavithamini K2.
Yidla izithelo nemifino emibalabala. I-carotenoid, uhlobo lukavithamini A, itholakala ezithelweni nemifino emibalabala. Ibhotela, ubisi, noshizi nakho kuyimithombo emihle yohlobo olusebenzayo lwevithamini A.
Gcina izitshalo zamathumbu ezinempilo. I-Vitamin K iguqulwa emgudwini wesisu. Yidla ukudla okuvutshiwe, thatha izithasiselo ze-probiotic, gwema ama-antibiotic ngaphandle uma kunesidingo (ucwaningo lwathola ukuthi ama-antibiotic abanzi anganciphisa ukukhiqizwa kukavithamini K ngo-75%).
Xoxa ngayo yonke imithi kanye nezithako zokudla ozithatha nodokotela wakho noma usokhemisi. Izidakamizwa eziningi, njenge-corticosteroids, i-prednisone, i-orlistat, ama-statins, i-thiazide diuretics, zingaphazamisa ibhalansi ethambile yamavithamini namaminerali emzimbeni. Qinisekisa ukuthi uyazi yonke imiphumela emibi nokusebenzisana kwemithi kanye nezithako "ezinempilo" ozithathayo.