It is also given to patients with heart stroke history. Rather, in studies shown that patients who regularly took vitamin B3 were more likely exposed to developing infections, liver problems, and internal bleeding. Researchers found out that niacin (vitamin B3) has no role in preventing heart problems, instead, have dreadful side effects. They are now saying that this vitamin should not be prescribed anymore. They are also saying that niacin can be fulfilled through eating salmon, tuna, or even beets.