I have been taking a 100 mg capsule of B complex four times a day for years and it has not been toxic to me. Like I said in previous posts, one should not take a particular B vitamin without taking a B complex also so the others aren’t imbalanced. I think this is what has kept me from getting nerve damage and pain during my GBS. Most B’s are water soluable so the more liquids you drink, the more you get rid of them from your body. People that retain water probably need B6…people with whistle marks from smoking are lacking B2. Lots of little ways the body tells us what it needs. I think it is a lot safer to take B’s than many of the prescription medicines. The one that really scares me is vitamin K – that can do alot of damage if you don’t know what you are doing. It has to do with the clotting of the blood. I do not mess with that one.