Vitamin K i stareyushchy organizm
Vitamin K — zhiroras tvormy vitamin, kotory bolshinstvo lyudey svyazyvaet v pervuyu ochered s svertyvayemost yu krovi. Eto verno — vitamin K neobkhodim dlya karboksilirovaniya neskolkikh faktorov svertyvaniya — no dlya pozhilykh eto lish chast obshchey kartiny. Vitamin K takzhe aktiviruyet osteokaltsin (belok, neobkhodim y dlya mineralizatsii kostey) i matriksny Gla-belok (MGP), kotory ingibiru yet otklozhenie kaltsiya v stenk akh arteriy. Eti roli stanovyatsya vse bolee vazhnymi s vozrastom.
Suschestv uyut dve osnovnye formy vitamina K, aktualnye dlya dobavok: K1 (fillokhino n, soderzh ashchiysya v listoVykh ovoshchakh) i K2 (menakinon, soderzh ashchiysya v fermentirovannoy pishche i sinteziruemyy kishechnymi bakteriyami). K1 v pervuyu ochered napravlyaetsya v pechen dlya produkrovaniya faktorov svertyvaniya. K2, osobenno podforma MK-7 s dlinnnym periodor poluvy vede niya, shirochee tsirkuliruyet i okazyvayet bolee suschestvennoe vliyaniye na vnepechyonochnye tkani, vklyuchaya kosti i arterii.
Svyazannye s vozrastom izmeneniya v usvoenii i potrebnosti
Vsasyvanie vitamina K zavisit ot zhira i sleduy et tomu zhe puti, chto i drugie zhiroras tvorimye vitaminy. Ryad svyazannykh s vozrastom izmeneniy vliyayet na eto:
- Sni zheniye potrebleniya pishchevykh zhirov u pozhilykh lyudey mozhet umenshit vsasyvanie vitamina K.
- Dlitelnoe primene nie antibiotikov — bolee rasprostr anennoe u pozhilykh — naru shayet kishechnye bakterii, sinteziruyushchie mena kinony, snizhaya endogennoye produk tsii K2.
- Snizhennaya fizicheskaya aktivnost i ubyvayushchaya funktsiya osteo blastov oznachayut, chto neobkhodimo bolshe aktivatsii osteokaltsina (trebuet K2) dlya podderzhaniya kachestva kostey.
Arterialnaya kaltsifikatsiya progressiruyet s vozrastom; dostatochny K2 trebuetsya dlya podder zhaniya aktivnosti MGP i ing ibirovaniya etogo protsessa.
Issledovaniya u pozhilykh lyudey pokazali, chto bolee vysokoye potreblenie vitamina K2 bylo svyazano s bole nizkim riskom serdechno-sosudistykh zabole vaniy i perelomov v prospektivnykh koh ortnykh d annykh (Geleijnse et al., 2004), chto svidetelstvuyet o tom, chto adekvatny status K2 imeet sushchestvennoe znachenie dlya zdorovya v etoy populyatsii.
Doza i bezopasnost dlya pozhilykh
Vitamin K otnositsya k odnomu iz naibolee bezopasnykh zhiroras tvorimykh vitaminov. Dopustimogo verkhnego urovnya potrebleniya dlya vitamina K ne ustanovleno, tak kak v klinicheskikh issledovaniyakh ne bylo dokum entiro vano neblagopriyatnykh effektov ot vysokogo pishchevogo ili supplementarnogo potrebleniya — za odnim kriticheskim isklyucheniem.
K1 i antikoagulyantny e preparaty — v chastnosti varfarin (i analogichnye antagonisty vitamina K) — predstavlyayut soboy naibolee vazhnoye soobrazhe niye bezopasnosti vitamina K dlya pozhilykh. Varfarin deystvuyet, blo kiruya rol vitamina K v aktivatsii faktorov svertyvaniya. Lyuboye znachitelnoe ili neposled ovatelnoye izmenenie potrebleniya vitamina K mozhet destabilizirovat kontrol antikoagulyatsii i libo uvelichi vat risk tromboza (esli potreblenie K vozrastayet), libo uveli chivat risk krovotecheniya (esli potreblenie K rezko sni zhaetsya). Lyuboy, nakhodya shchiysya na terapii varfarinom, dolzhen obsuzhdal s vrachom lyubye izmeneniya v prieme dobavok vitamina K.
Novye antikoag ulyant y (apiksaban, rivar oksaban, dabigatran) NE vzaimodeystvuyut s vitaminom K takim zhe ob razom — oni deystvuyut cherez razlichnye mekhanizmy, i priom vitamina K v dobavkakh v obshchem mozhet primenyatsya s etimi preparatami bez destabilizatsii antikoagulyatsii.
NOW Vitamin K-2 (MK7) 100mcg 60 veg. caps., OstroVit Vitamin D3 + K2 90 tabs i OstroVit Vitamin K2 200 Natto MK-7 90tabs — vse dostupny na maxfit.ee — obespechivayut formu K2 MK-7, kotoraya predpochti tel na pered K1 ili bolee korotkotsepo chnymi formami K2 (MK-4) dlya kostey i sosudistoy podporzhki blagodarya bolee dlinnomu periodu poluvyve deniya i bolee shiro komu raspredeleniyu v tkanyakh.
Vzaimodeystviya s lekarstvami
Vzaimodeystvie s varfarinom yavlyaetsya osnovnoy proBlemoy, no sushchestvuyut i drugiye vzaimodeystviya:
- Antibiotiki shiroko go spektra mogut umenshit produkt siyu menakinonov kishechnymi bakteriyami, sni zhaya status K2 v techenie kursa lecheniya.
- Orlistat (blokiruyushchy vsasyvanie zhira) umen shayet vsasyvanie zhiroras tvorimykh vitaminov, vklyuchaya K1 i K2.
- Sekvestranty zhelchnykh kislot (kholestiramin, kolesevelam) umen shayut vsasyvanie vsekh zhiroras tvorimykh vitaminov.
- Mineralnoe maslo (ispolzuemoe nekotorymi pozhilymi lyudmi kak slabitelnoe) naru shayet vsasyvanie zhiroras tvorimykh vitaminov pri chastom primenenii.
Kogda dopolnyat vitamin K posle 50 let
Priom vitamina K naibolee aktual en dlya pozhilykh, u kotorykh:
- Dokumentiro vana nizkaya mineraln aya plotnost kostey (osteopen iya ili osteoporoz)
- Potreblenie listovykh ovoshchey ili fermentiro vanny kh produktov ogranicheno
- Byl provedon dlit elny kurs antib iotikov, naru shayushchiy kishechnuyu mikro biotu
- Prini mayutsya dobavki vitamina D — vitaminy D i K2 igrut sinergeticheskie roli v metabolizme kaltsiya, i dopol nenie D bez dostatochnogo K2 mozhet sposobst vovat otklozheniyu kaltsiya v myagkikh tkanyakh
Kombinatsiya vitaminov D3 i K2 MK-7 shiro ko rekomenduyetsya v literature o dobavkakh dlya pozhilykh kak ratsionalnoye sochetaniye. Mnogie kachestvennye formuly multivitaminov dlya pozhilykh teper vklyuchayut oba, priznavaya funktsional nuyu vzaimozavisimost.
Chasto zadavaemye voprosy
Mogut li pozhilye na varfarine prinimat dobavki vitamina K2?
Eto trebuyet neposredstvennogo rukovod stva vracha. Posledovatelnoye ezhednevnoye potreblenie fiksiro vanno y nizkoy dozy K2 (mene 45 mkg v den) mozhet perenositsya pri monitoringe i korrektsii MNO, no neregulyarny y ili vysokodoznyi priom K opasen dlya polzovateely varfarina. Nikogda ne izmenyayte potreblenie vitamina K, ne obsu div eto s komandoy menedzhmenta antikoagulyatsii.
Pomogayet li vitamin K2 pri osteoporoze posle 50 let?
Vitamin K2 aktiviruyet osteokaltsin, kotory vklyuchayet kaltsy v kos tny matriksu. Nablyudatelnye dann ye svyazyvayut bolee vysokoe potreblenie K2 s bolee nizkim riskom perelomov u pozhilykh (Geleijnse et al., 2004), i nekotorye dan nye RCT svidetelstvuyut o polze dlya podder zhaniya mineralnoy plotnosti kostey. K2 luchshe vsego ispol zovat kak chast komplek snoy strategii zdorovya kostey vme ste s vitaminom D, adekvatnym kaltsiem iz pishchi i uprazhneniyami s nag ruzkoy vesa.
Yest li raznitsa mezhdu vitaminom K2 MK-4 i MK-7 dlya pozhilykh?
MK-7 imet znachitel no dolshy period poluvyvede niya, chem MK-4, chto oznachayet, chto odna sutochnaya doza obesp echivayet bolee stabilnye urovy nyi v techenie vsego dnya i nochi. Dlya kostey i kardiovaskularnykh tseley u pozhilykh MK-7 v dozakh 90–200 mkg v den yavlyaetsya predpochtitelno y formoy na osnove tekushchikh dokazatelstv.
Literatura
Geleijnse, J. M., Vermeer, C., Grobbee, D. E., Schurgers, L. J., Knapen, M. H., van der Meer, I. M., Hofman, A., & Witteman, J. C. (2004). Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study. Journal of Nutrition, 134(11), 3100-3105.
Knapen, M. H., Schurgers, L. J., & Vermeer, C. (2007). Vitamin K2 supplementation improves hip bone geometry and bone strength indices in postmenopausal women. Osteoporosis International, 18(7), 963-972.
Schurgers, L. J., & Vermeer, C. (2000). Determination of phylloquinone and menaquinones in food: effect of food matrix on circulating vitamin K concentrations. Haemostasis, 30(6), 298-307.
