The present invention relates to a method for increasing the amount of K2 vitamin obtained by culturing at least one stem of a lactic bacteria that produces K2 vitamin, wherein the culture of said stem is realized in resting-cells conditions so that the amount of K2 vitamin produced by the resting-cells culture is higher by a ratio of at least 1.2 to that obtained by the culture of said stem under standard fermentation conditions. The present invention also relates to the biomass obtained from the culture of a lactic bacteria producing K2 vitamin according to the above method. The invention further relates to a method for producing K2 vitamin, to a method for preparing food products, including fermented products and/or fresh diary products, enriched with K2 vitamin, and to the food products thus obtained.
