Vitamini V12 – (siankobalamin) dar jarayoni khunhosilgardi ishtirok mekunand. Az norasogii vitamini V12 kamkhuni ruy medihad. In vitamin dar jigar, gurda, mahsuloti mohi, khususan jigar va tukhmhoyash) bisyortar ast.
Vitamin V12 dar gusht, shir, panir, zardii tukhm kamtar ast.