I take b-100 2x a day for cholesterol, really for the niacin, is that a good amount?

Probably not: Most b-100's contain b3 in the form of niacineamide, which does not lower cholesterol, not niacin. The doses of Niacin shown to lower cholesterol are at least 500 mg/day. But while Niacin lowers LDL & raises hdl, it's not clear if this lowers risk of heart disease, in part because cholesterol is not the main cause of heart disease. See http://www.Ccjm.Org/content/79/1/38.Full re: Niacin & comment:.