Peata,
SourceAt the other end of the spectrum there are people who experience nausea and loss of appetite on a dose of 1,000 mg three times a day. When this happens, if these people are tested they will have elevated liver enzymes that correlate closely with the sensation of nausea. These people are very sensitive to niacinamide and they need to take less. As their nausea clears their liver enzymes will return to normal and never has there been any liver damage resulting from this transient elevation of liver enzymes.