{"id":581,"date":"2016-03-11T15:09:46","date_gmt":"2016-03-11T14:09:46","guid":{"rendered":"https:\/\/viscojis.cz\/teens\/2016\/03\/11\/myty-kolem-vitaminu-b12\/"},"modified":"2025-03-14T14:21:09","modified_gmt":"2025-03-14T13:21:09","slug":"myty-kolem-vitaminu-b12","status":"publish","type":"post","link":"https:\/\/viscojis.cz\/teens\/myty-kolem-vitaminu-b12\/","title":{"rendered":"M\u00fdty kolem vitaminu B12"},"content":{"rendered":"

O vitaminu B12, jeho zdroj\u00edch, v\u00fdznamu pro lidsk\u00fd organismus a projevech nedostatku. Dozv\u00edte se, jak\u00e9 m\u00fdty koluj\u00ed o tomto vitaminu a zda jsou pravdiv\u00e9.<\/span><\/span><\/p>\n

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P\u0159esto\u017ee vitaminu B12 pot\u0159ebujeme jen n\u011bkolik mikrogram\u016f denn\u011b, je pro lidsk\u00fd organismus nepostradateln\u00fd. Jeho nedostatek vede k v\u00e1\u017en\u00fdm zdravotn\u00edm poruch\u00e1m. <\/span>Mezi zast\u00e1nci alternativn\u00edch zp\u016fsob\u016f stravov\u00e1n\u00ed, a nejen mezi nimi, koluje spousta m\u00fdt\u016f o tom, ve kter\u00fdch potravin\u00e1ch se tento vitamin vyskytuje a jestli je mo\u017en\u00e9 jej p\u0159ij\u00edmat v dostate\u010dn\u00e9m mno\u017estv\u00ed pouze z rostlinn\u00fdch zdroj\u016f. Jak to tedy je?<\/span><\/p>\n

<\/span> <\/p>\n

<\/span>Vitamin B12 pat\u0159\u00ed mezi vitaminy rozpustn\u00e9 ve vod\u011b, ale v n\u011bkter\u00fdch ohledech se od nich odli\u0161uje:<\/span><\/p>\n

    \n
  1. um\u00edme si jej ukl\u00e1dat do z\u00e1soby<\/strong> (podobn\u011b jako vitaminy rozpustn\u00e9 v tuc\u00edch),<\/span><\/li>\n
  2. d\u00edky z\u00e1sob\u00e1m v t\u011ble se jeho<\/strong> nedostatek projev\u00ed a\u017e za n\u011bkolik let<\/strong> (na rozd\u00edl od nap\u0159. vitaminu C, jeho\u017e t\u011b\u017ek\u00fd nedostatek se projev\u00ed ji\u017e po n\u011bkolika t\u00fddnech kurd\u011bjemi),<\/span><\/li>\n
  3. vyskytuje se<\/strong> t\u00e9m\u011b\u0159 v\u00fdhradn\u011b v potravin\u00e1ch \u017eivo\u010di\u0161n\u00e9ho p\u016fvodu<\/strong> (ostatn\u00ed vitaminy rozpustn\u00e9 ve vod\u011b se vyskytuj\u00ed v rostlinn\u00e9 i \u017eivo\u010di\u0161n\u00e9 strav\u011b nebo pouze v rostlinn\u00e9).<\/span><\/span><\/span><\/li>\n<\/ol>\n


    Jak se projevuje nedostatek vitaminu B12?
    <\/span><\/strong><\/span>
    Nedostatek vitaminu B12 se projevuje poruchami nervov\u00e9 \u010dinnosti a pozd\u011bji megaloblasticku an\u00e9mi\u00ed. Nervov\u00e9 poruchy za\u010d\u00ednaj\u00ed brn\u011bn\u00edm a necitlivost\u00ed rukou a nohou, d\u00e1le pot\u00ed\u017eemi s ch\u016fz\u00ed, zmatenost\u00ed, <\/span>demenc\u00ed<\/span> <\/span>aj. Pokud se stav nel\u00e9\u010d\u00ed, nastupuje an\u00e9mie, kdy se z nedostatku B12 tvo\u0159\u00ed v kostn\u00ed d\u0159eni velk\u00e9 nezral\u00e9 \u010derven\u00e9 krvinky. <\/span><\/p>\n


    Jak se dost\u00e1v\u00e1 vitamin B12 do potravin?
    <\/span><\/strong>
    Vitamin B12 vznik\u00e1 pomoc\u00ed mikroorganism\u016f v za\u017e\u00edvac\u00edm traktu b\u00fdlo\u017eravc\u016f. Je proto p\u0159\u00edtomen v potravin\u00e1ch p\u016fvodem z b\u00fdlo\u017eravc\u016f, nebo i z maso\u017eravc\u016f, kte\u0159\u00ed se b\u00fdlo\u017eravci \u017eiv\u00ed. N\u011bkter\u00e9 potraviny, hlavn\u011b obiloviny, se t\u00edmto vitaminem obohacuj\u00ed, nebo se p\u0159id\u00e1v\u00e1 do dopl\u0148k\u016f stravy.
    <\/span><\/p>\n

    Ve kter\u00fdch potravin\u00e1ch se vitamin B12 vyskytuje?
    <\/span><\/strong>
    Pro \u010dlov\u011bka jsou nejd\u016fle\u017eit\u011bj\u0161\u00edm a p\u0159irozen\u00fdm zdrojem potraviny \u017eivo\u010di\u0161n\u00e9ho p\u016fvodu<\/strong>, p\u0159edev\u0161\u00edm plody mo\u0159e, vnit\u0159nosti, ryby, maso, m\u00e9n\u011b pak ml\u00e9ko a ml\u00e9\u010dn\u00e9 v\u00fdrobky, vejce. <\/span><\/p>\n

    V rostlinn\u00fdch zdroj\u00edch byl nalezen tento vitamin pouze v n\u011bkter\u00fdch druz\u00edch jedl\u00fdch mo\u0159sk\u00fdch \u0159as<\/strong> \u2013 rody Enteromorpha<\/i> a Porphyra<\/i> (zn\u00e1m\u00e1 jako nori k v\u00fdrob\u011b japonsk\u00e9ho pokrmu sushi<\/span>), v n\u011bkter\u00fdch druz\u00edch jedl\u00fdch hub<\/strong> (li\u0161ka obecn\u00e1, stro\u010dek trubkovit\u00fd a japonsk\u00e1 houba shiitake \u2013 hou\u017eevnatec jedl\u00fd) a v tempehu, co\u017e je fermentovan\u00fd v\u00fdrobek ze s\u00f3ji. <\/span><\/p>\n

    Mno\u017estv\u00ed, kter\u00e9 bychom museli ale denn\u011b zkonzumovat, nen\u00ed \u017e\u00e1douc\u00ed a ani re\u00e1ln\u00e9. Tak nap\u0159\u00edklad doporu\u010denou denn\u00ed d\u00e1vku B12 obsahuje 1 kg \u010derstv\u00fdch li\u0161ek nebo 100 g su\u0161en\u00fdch, 50 g su\u0161en\u00fdch shitakee a 10 g uveden\u00fdch mo\u0159sk\u00fdch \u0159as. <\/span><\/p>\n

    Ot\u00e1zku d\u00e1le z\u016fst\u00e1v\u00e1, nakolik se z t\u011bchto rostlinn\u00fdch zdroj\u016f vitamin B12 dok\u00e1\u017ee vst\u0159ebat a nakolik se m\u016f\u017eeme spolehnout, \u017ee se bude vyskytovat v dostate\u010dn\u00e9 m\u00ed\u0159e v produktech r\u016fzn\u00fdch v\u00fdrobc\u016f? To zat\u00edm nev\u00edme.<\/span><\/p>\n

    D\u0159\u00edve se myslelo, \u017ee tak\u00e9 n\u011bkter\u00e9 jedl\u00e9 sinice, zejm\u00e9na rod Spirulina<\/i>, jsou vhodn\u00fdm zdrojem vitaminu B12. Bylo ale prok\u00e1z\u00e1no, \u017ee Spirulina<\/i> a jin\u00e9 druhy sinic vitamin B12 neobsahuj\u00ed.<\/span><\/p>\n

     <\/p>\n

    Kdo je ohro\u017een nedostatkem vitaminu B12?
    <\/span><\/strong>
    Mezi nejv\u00edce ohro\u017een\u00e9 skupiny pat\u0159\u00ed:<\/span><\/p>\n