B vitamin overdose?

Energy drinks are all the craze. My husband uses those little bottles of 5-HOUR ENERGY drinks. I read the label and it has extremely high amounts of Niacin and B12. I know certain vitamins are stored in the body while others aren't. Are these B vitamin doses safe on a regular basis? Also what happens to the body when high doses of B vitamins are ingested like this?

[didi2901]

B vitamins are water solubles (like vitamin C) the excess shouldl be flushed out by the urine.

[sweetadeline]

..that is until the energy drinks give you cysts in your kidneys and ruin your gallballder....happened to me:(