Too much niacin can be toxic

Although it is touted on the Internet as a way to beat a drug test, taking large doses of the over-the-counter supplement niacin, also known as vitamin B3, is both ineffective and potentially dangerous, researchers at the University of Pennsylvania warn.

Emergency physician Manoj K. Mittal of Children’s Hospital of Philadelphia and colleagues reported last month in the Annals of Emergency Medicine that they had treated four patients for niacin overdose during the last two years. All had taken large quantities of the vitamin after using marijuana or cocaine, and all recovered from the niacin overdose.

Niacin is one of several over-the-counter supplements popularly believed to subvert the results of drug testing. It is erroneously believed, the authors write, that massive doses of vitamin B3 can rapidly flush drugs from a user’s body and produce a negative drug test for marijuana and cocaine by speeding up metabolism.

In reality, they write, it can prove toxic, causing heart palpitations, vomiting, blood sugar abnormalities and liver failure. The recommended daily dose of niacin is about 14 to 16 milligrams per day; a 14-year-old who was treated at Children’s Hospital said he took 5,500 milligrams.