i think your body will tell you when it's had enough. Of course I'm asuming you're not talkking about pills or cupplements, other than the kind that is plain old food. Kefir, yogurt, cultured veg. kombucha... Sometimes I go through a lot of cultured veg. just crave it, and might eat a jar a day for a few days. Or, might OD on kombucha. Neither is fatal...but the kombucha can keep you up, something like coffee. In my case, buzzing in my veins.